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关于iOS 的一些总结

發(fā)布時(shí)間：2023/12/3 综合教程 25 生活家

生活随笔收集整理的這篇文章主要介紹了关于iOS 的一些总结小編覺(jué)得挺不錯(cuò)的,現(xiàn)在分享給大家,幫大家做個(gè)參考.

總結(jié)了幾個(gè)月的東西終于能和大家分享了，不多說(shuō)，直接看東西！由于比較懶部分直接從別人那里拿來(lái)的，在這里感謝一下原作者。不喜勿噴

1、禁止手機(jī)睡眠

[UIApplication sharedApplication].idleTimerDisabled = YES;

2、隱藏某行cell

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
// 如果是你需要隱藏的那一行，返回高度為0if(indexPath.row == YouWantToHideRow)return 0; return 44;
}// 然后再你需要隱藏cell的時(shí)候調(diào)用
[self.tableView beginUpdates];
[self.tableView endUpdates];

3、禁用button高亮

button.adjustsImageWhenHighlighted = NO;
或者在創(chuàng)建的時(shí)候UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];

4、tableview遇到這種報(bào)錯(cuò)failed to obtain a cell from its dataSource

是因?yàn)槟愕腸ell被調(diào)用的早了。先循環(huán)使用了cell，后又創(chuàng)建cell。順序錯(cuò)了
可能原因：1、xib的cell沒(méi)有注冊(cè) 2、內(nèi)存中已經(jīng)有這個(gè)cell的緩存了(也就是說(shuō)通過(guò)你的cellId找到的cell并不是你想要的類(lèi)型)，這時(shí)候需要改下cell的標(biāo)識(shí)

5、cocoa pods報(bào)這個(gè)錯(cuò)誤：unable to access 'https://github.com/facebook/pop.git/': Operation timed out after 0 milliseconds with 0 out of 0 bytes received

解決辦法：原因可能是網(wǎng)絡(luò)問(wèn)題，網(wǎng)絡(luò)請(qǐng)求超時(shí)了，只需要重試就行了

6、cocoa pods 出現(xiàn)ERROR: While executing gem ... (Errno::EPERM)

解決辦法：
https://segmentfault.com/q/1010000002926243

7、動(dòng)畫(huà)切換window的根控制器

// options是動(dòng)畫(huà)選項(xiàng)
[UIView transitionWithView:[UIApplication sharedApplication].keyWindow duration:0.5f options:UIViewAnimationOptionTransitionCrossDissolve animations:^{BOOL oldState = [UIView areAnimationsEnabled];[UIView setAnimationsEnabled:NO];[UIApplication sharedApplication].keyWindow.rootViewController = [RootViewController new];[UIView setAnimationsEnabled:oldState];} completion:^(BOOL finished) {}];

8、去除數(shù)組中重復(fù)的對(duì)象

NSArray *newArr = [oldArr valueForKeyPath:@“@distinctUnionOfObjects.self"];

9、編譯的時(shí)候遇到 no such file or directory: ／users／apple／XXX

是因?yàn)榫幾g的時(shí)候，在此路徑下找不到這個(gè)文件，解決這個(gè)問(wèn)題，首先是是要檢查缺少的文件是不是在工程中，如果不在工程中，需要從本地拖進(jìn)去，如果發(fā)現(xiàn)已經(jīng)存在工程中了，或者拖進(jìn)去還是報(bào)錯(cuò)，這時(shí)候需要去build phases中搜索這個(gè)文件，這時(shí)候很可能會(huì)搜出現(xiàn)兩個(gè)相同的文件，這時(shí)候，有一個(gè)路徑是正確的，刪除另外一個(gè)即可。如果刪除了還是不行，需要把兩個(gè)都刪掉，然后重新往工程里拖進(jìn)這個(gè)文件即可

build phases

10、iOS8系統(tǒng)中，tableView最好實(shí)現(xiàn)下-tableView: heightForRowAtIndexPath:這個(gè)代理方法，要不然在iOS8中可能就會(huì)出現(xiàn)顯示不全或者無(wú)法響應(yīng)事件的問(wèn)題

11、iOS8中實(shí)現(xiàn)側(cè)滑功能的時(shí)候這個(gè)方法必須實(shí)現(xiàn)，要不然在iOS8中無(wú)法側(cè)滑

// 必須寫(xiě)的方法，和editActionsForRowAtIndexPath配對(duì)使用，里面什么不寫(xiě)也行
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {}

12、三個(gè)通知

NSSystemTimeZoneDidChangeNotification監(jiān)聽(tīng)修改時(shí)間界面的兩個(gè)按鈕狀態(tài)變化
UIApplicationSignificantTimeChangeNotification 監(jiān)聽(tīng)用戶(hù)改變時(shí)間（只要點(diǎn)擊自動(dòng)設(shè)置按鈕就會(huì)調(diào)用） NSSystemClockDidChangeNotification 監(jiān)聽(tīng)用戶(hù)修改時(shí)間（時(shí)間不同才會(huì)調(diào)用）

13、SDWebImage本地緩存有時(shí)候會(huì)害人。如果之前緩存過(guò)一張圖片，即使下次服務(wù)器換了這張圖片，但是圖片url沒(méi)換，用sdwebimage下載下來(lái)的還是以前那張,所以遇到這種問(wèn)題，不要先去懟服務(wù)器，清空下緩存再試就好了。

14、上線前注意：

1）、刪掉代碼中所有的測(cè)試代碼
2）、如果后臺(tái)有審核模式，提醒后臺(tái)開(kāi)啟此模式
3）、主流程再跑一跑
4）、全局搜索waring，檢查所有標(biāo)記waring的地方

15、跳進(jìn)app權(quán)限設(shè)置

// 跳進(jìn)app設(shè)置if (UIApplicationOpenSettingsURLString != NULL) {UIApplication *application = [UIApplication sharedApplication];NSURL *URL = [NSURL URLWithString:UIApplicationOpenSettingsURLString];if ([application respondsToSelector:@selector(openURL:options:completionHandler:)]) {[application openURL:URL options:@{}
                       completionHandler:nil];} else {[application openURL:URL];}}

16、給一個(gè)view截圖

UIGraphicsBeginImageContextWithOptions(view.bounds.size, YES, 0.0);[view.layer renderInContext:UIGraphicsGetCurrentContext()];UIImage *img = UIGraphicsGetImageFromCurrentImageContext();UIGraphicsEndImageContext();

17、開(kāi)發(fā)中如果要?jiǎng)討B(tài)修改tableView的tableHeaderView或者tableFooterView的高度，需要給tableView重新設(shè)置，而不是直接更改高度。正確的做法是重新設(shè)置一下tableView.tableFooterView = 更改過(guò)高度的view。為什么？其實(shí)在iOS8以上直接改高度是沒(méi)有問(wèn)題的，在iOS8中出現(xiàn)了contentSize不準(zhǔn)確的問(wèn)題，這是解決辦法。

18、注意對(duì)象為nil的時(shí)候，調(diào)用此對(duì)象分類(lèi)的方法不會(huì)執(zhí)行

19、collectionView的內(nèi)容小于其寬高的時(shí)候是不能滾動(dòng)的，設(shè)置可以滾動(dòng)：

collectionView.alwaysBounceHorizontal = YES;
collectionView.alwaysBounceVertical = YES;

20、設(shè)置navigationBar上的title顏色和大小

    [self.navigationController.navigationBar setTitleTextAttributes:@{NSForegroundColorAttributeName : [UIColor youColor], NSFontAttributeName : [UIFont systemFontOfSize:15]}]

21、顏色轉(zhuǎn)圖片

+ (UIImage *)cl_imageWithColor:(UIColor *)color {CGRect rect = CGRectMake(0.0f, 0.0f, 1.0f, 1.0f);UIGraphicsBeginImageContext(rect.size);CGContextRef context = UIGraphicsGetCurrentContext();CGContextSetFillColorWithColor(context, [color CGColor]);CGContextFillRect(context, rect);UIImage *image = UIGraphicsGetImageFromCurrentImageContext();UIGraphicsEndImageContext();return image;
}

22、view設(shè)置圓角

#define ViewBorderRadius(View, Radius, Width, Color)\
\
[View.layer setCornerRadius:(Radius)];\
[View.layer setMasksToBounds:YES];\
[View.layer setBorderWidth:(Width)];\
[View.layer setBorderColor:[Color CGColor]] // view圓角

23、強(qiáng)／弱引用

#define WeakSelf(type)  __weak typeof(type) weak##type = type; // weak
#define StrongSelf(type)  __strong typeof(type) type = weak##type; // strong

24、由角度轉(zhuǎn)換弧度

#define DegreesToRadian(x) (M_PI * (x) / 180.0)

25、由弧度轉(zhuǎn)換角度

#define RadianToDegrees(radian) (radian*180.0)/(M_PI)

26、獲取圖片資源

#define GetImage(imageName) [UIImage imageNamed:[NSString stringWithFormat:@"%@",imageName]]

27、獲取temp

#define PathTemp NSTemporaryDirectory()

28、獲取沙盒 Document

#define PathDocument [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) firstObject]

29、獲取沙盒 Cache

#define PathCache [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) firstObject]

30、GCD代碼只執(zhí)行一次

#define kDISPATCH_ONCE_BLOCK(onceBlock) static dispatch_once_t onceToken; dispatch_once(&onceToken, onceBlock);

31、自定義NSLog

#ifdef DEBUG
#define NSLog(fmt, ...) NSLog((@"%s [Line %d] " fmt), __PRETTY_FUNCTION__, __LINE__, ##__VA_ARGS__)
#else
#define NSLog(...)
#endif

32、Font

#define FontL(s)             [UIFont systemFontOfSize:s weight:UIFontWeightLight]
#define FontR(s)             [UIFont systemFontOfSize:s weight:UIFontWeightRegular]
#define FontB(s)             [UIFont systemFontOfSize:s weight:UIFontWeightBold]
#define FontT(s)             [UIFont systemFontOfSize:s weight:UIFontWeightThin]
#define Font(s)              FontL(s)

33、FORMAT

#define FORMAT(f, ...)      [NSString stringWithFormat:f, ## __VA_ARGS__]

34、在主線程上運(yùn)行

#define kDISPATCH_MAIN_THREAD(mainQueueBlock) dispatch_async(dispatch_get_main_queue(), mainQueueBlock);

35、開(kāi)啟異步線程

#define kDISPATCH_GLOBAL_QUEUE_DEFAULT(globalQueueBlock) dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), globalQueueBlocl);

36、通知

#define NOTIF_ADD(n, f)     [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(f) name:n object:nil]
#define NOTIF_POST(n, o)    [[NSNotificationCenter defaultCenter] postNotificationName:n object:o]
#define NOTIF_REMV()        [[NSNotificationCenter defaultCenter] removeObserver:self]

37、隨機(jī)顏色

+ (UIColor *)RandomColor {NSInteger aRedValue = arc4random() % 255;NSInteger aGreenValue = arc4random() % 255;NSInteger aBlueValue = arc4random() % 255;UIColor *randColor = [UIColor colorWithRed:aRedValue / 255.0f green:aGreenValue / 255.0f blue:aBlueValue / 255.0f alpha:1.0f];return randColor;
}

38、獲取window

+(UIWindow*)getWindow {UIWindow* win = nil; //[UIApplication sharedApplication].keyWindow;for (id item in [UIApplication sharedApplication].windows) {if ([item class] == [UIWindow class]) {if (!((UIWindow*)item).hidden) {win = item;break;}}}return win;
}

39、修改textField的placeholder的字體顏色、大小

[textField setValue:[UIColor redColor] forKeyPath:@"_placeholderLabel.textColor"];
[textField setValue:[UIFont boldSystemFontOfSize:16] forKeyPath:@"_placeholderLabel.font"];

40、統(tǒng)一收起鍵盤(pán)

[[[UIApplication sharedApplication] keyWindow] endEditing:YES];

41、控制屏幕旋轉(zhuǎn)，在控制器中寫(xiě)

/** 是否支持自動(dòng)轉(zhuǎn)屏 */
- (BOOL)shouldAutorotate {return YES;
}/** 支持哪些屏幕方向 */
- (UIInterfaceOrientationMask)supportedInterfaceOrientations {return UIInterfaceOrientationMaskLandscapeLeft | UIInterfaceOrientationMaskLandscapeRight;
}/** 默認(rèn)的屏幕方向（當(dāng)前ViewController必須是通過(guò)模態(tài)出來(lái)的UIViewController（模態(tài)帶導(dǎo)航的無(wú)效）方式展現(xiàn)出來(lái)的，才會(huì)調(diào)用這個(gè)方法） */
- (UIInterfaceOrientation)preferredInterfaceOrientationForPresentation {return UIInterfaceOrientationLandscapeLeft | UIInterfaceOrientationLandscapeRight;
}

42、獲取app緩存大小

- (CGFloat)getCachSize {NSUInteger imageCacheSize = [[SDImageCache sharedImageCache] getSize];//獲取自定義緩存大小//用枚舉器遍歷 一個(gè)文件夾的內(nèi)容//1.獲取 文件夾枚舉器NSString *myCachePath = [NSHomeDirectory() stringByAppendingPathComponent:@"Library/Caches"];NSDirectoryEnumerator *enumerator = [[NSFileManager defaultManager] enumeratorAtPath:myCachePath];__block NSUInteger count = 0;//2.遍歷for (NSString *fileName in enumerator) {NSString *path = [myCachePath stringByAppendingPathComponent:fileName];NSDictionary *fileDict = [[NSFileManager defaultManager] attributesOfItemAtPath:path error:nil];count += fileDict.fileSize;//自定義所有緩存大小}// 得到是字節(jié)  轉(zhuǎn)化為MCGFloat totalSize = ((CGFloat)imageCacheSize+count)/1024/1024;return totalSize;
}

43、清理app緩存

- (void)handleClearView {//刪除兩部分//1.刪除 sd 圖片緩存//先清除內(nèi)存中的圖片緩存[[SDImageCache sharedImageCache] clearMemory];//清除磁盤(pán)的緩存[[SDImageCache sharedImageCache] clearDisk];//2.刪除自己緩存NSString *myCachePath = [NSHomeDirectory() stringByAppendingPathComponent:@"Library/Caches"];[[NSFileManager defaultManager] removeItemAtPath:myCachePath error:nil];
}

44、模型轉(zhuǎn)字典

static NSSet *classes;- (NSMutableDictionary *)getParameterDictionary {NSMutableDictionary *dict = [NSMutableDictionary dictionary];Class c = self.class;while (c) {unsigned count;objc_property_t *properties = class_copyPropertyList([c class], &count);for (int i = 0; i < count; i++) {NSString *key = [NSString stringWithUTF8String:property_getName(properties[i])];dict[key] = [self valueForKey:key];}free(properties);// 獲得父類(lèi)c = class_getSuperclass(c);if ([self isClassFromFoundation:c]) break;}return dict;
}- (BOOL)isClassFromFoundation:(Class)c
{if (c == [NSObject class] || c == [NSManagedObject class]) return YES;__block BOOL result = NO;[[self foundationClasses] enumerateObjectsUsingBlock:^(Class foundationClass, BOOL *stop) {if ([c isSubclassOfClass:foundationClass]) {result = YES;*stop = YES;}}];return result;
}- (NSSet *)foundationClasses
{if (classes == nil) {// 集合中沒(méi)有NSObject，因?yàn)閹缀跛械念?lèi)都是繼承自NSObject，具體是不是NSObject需要特殊判斷classes = [NSSet setWithObjects:[NSURL class],[NSDate class],[NSValue class],[NSData class],[NSError class],[NSArray class],[NSDictionary class],[NSString class],[NSAttributedString class], nil];}return classes;
}

45、交換兩個(gè)方法實(shí)現(xiàn)

Class aClass = [self class]; SEL originalSelector = @selector(viewWillAppear:); SEL swizzledSelector = @selector(xxx_viewWillAppear:); Method originalMethod = class_getInstanceMethod(aClass, originalSelector); Method swizzledMethod = class_getInstanceMethod(aClass, swizzledSelector); BOOL didAddMethod = class_addMethod(aClass, originalSelector, method_getImplementation(swizzledMethod), method_getTypeEncoding(swizzledMethod)); if (didAddMethod) { class_replaceMethod(aClass, swizzledSelector, method_getImplementation(originalMethod), method_getTypeEncoding(originalMethod)); } else { method_exchangeImplementations(originalMethod, swizzledMethod); }

46、打印百分號(hào)和引號(hào)

    NSLog(@"%%");NSLog(@"\"");

47、幾個(gè)常用權(quán)限判斷

    if ([CLLocationManager authorizationStatus] ==kCLAuthorizationStatusDenied) {NSLog(@"沒(méi)有定位權(quán)限");}AVAuthorizationStatus statusVideo = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];if (statusVideo == AVAuthorizationStatusDenied) {NSLog(@"沒(méi)有攝像頭權(quán)限");}//是否有麥克風(fēng)權(quán)限AVAuthorizationStatus statusAudio = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeAudio];if (statusAudio == AVAuthorizationStatusDenied) {NSLog(@"沒(méi)有錄音權(quán)限");}[PHPhotoLibrary requestAuthorization:^(PHAuthorizationStatus status) {if (status == PHAuthorizationStatusDenied) {NSLog(@"沒(méi)有相冊(cè)權(quán)限");}}];

48、獲取手機(jī)型號(hào)

    + (NSString *)getDeviceInfo {struct utsname systemInfo;uname(&systemInfo);NSString *platform = [NSString stringWithCString:systemInfo.machine encoding:NSASCIIStringEncoding];if ([platform isEqualToString:@"iPhone1,1"]) return @"iPhone 2G";if ([platform isEqualToString:@"iPhone1,2"]) return @"iPhone 3G";if ([platform isEqualToString:@"iPhone2,1"]) return @"iPhone 3GS";if ([platform isEqualToString:@"iPhone3,1"]) return @"iPhone 4";if ([platform isEqualToString:@"iPhone3,2"]) return @"iPhone 4";if ([platform isEqualToString:@"iPhone3,3"]) return @"iPhone 4";if ([platform isEqualToString:@"iPhone4,1"]) return @"iPhone 4S";if ([platform isEqualToString:@"iPhone5,1"]) return @"iPhone 5";if ([platform isEqualToString:@"iPhone5,2"]) return @"iPhone 5";if ([platform isEqualToString:@"iPhone5,3"]) return @"iPhone 5c";if ([platform isEqualToString:@"iPhone5,4"]) return @"iPhone 5c";if ([platform isEqualToString:@"iPhone6,1"]) return @"iPhone 5s";if ([platform isEqualToString:@"iPhone6,2"]) return @"iPhone 5s";if ([platform isEqualToString:@"iPhone7,1"]) return @"iPhone 6 Plus";if ([platform isEqualToString:@"iPhone7,2"]) return @"iPhone 6";if ([platform isEqualToString:@"iPhone8,1"]) return @"iPhone 6s";if ([platform isEqualToString:@"iPhone8,2"]) return @"iPhone 6s Plus";// 日行兩款手機(jī)型號(hào)均為日本獨(dú)占，可能使用索尼FeliCa支付方案而不是蘋(píng)果支付if ([platform isEqualToString:@"iPhone9,1"])    return @"國(guó)行、日版、港行iPhone 7";if ([platform isEqualToString:@"iPhone9,2"])    return @"港行、國(guó)行iPhone 7 Plus";if ([platform isEqualToString:@"iPhone9,3"])    return @"美版、臺(tái)版iPhone 7";if ([platform isEqualToString:@"iPhone9,4"])    return @"美版、臺(tái)版iPhone 7 Plus";if ([platform isEqualToString:@"iPhone8,4"]) return @"iPhone SE";if ([platform isEqualToString:@"iPod1,1"]) return @"iPod Touch 1G";if ([platform isEqualToString:@"iPod2,1"]) return @"iPod Touch 2G";if ([platform isEqualToString:@"iPod3,1"]) return @"iPod Touch 3G";if ([platform isEqualToString:@"iPod4,1"]) return @"iPod Touch 4G";if ([platform isEqualToString:@"iPod5,1"]) return @"iPod Touch 5G";if ([platform isEqualToString:@"iPad1,1"]) return @"iPad 1G";if ([platform isEqualToString:@"iPad2,1"]) return @"iPad 2";if ([platform isEqualToString:@"iPad2,2"]) return @"iPad 2";if ([platform isEqualToString:@"iPad2,3"]) return @"iPad 2";if ([platform isEqualToString:@"iPad2,4"]) return @"iPad 2";if ([platform isEqualToString:@"iPad2,5"]) return @"iPad Mini 1G";if ([platform isEqualToString:@"iPad2,6"]) return @"iPad Mini 1G";if ([platform isEqualToString:@"iPad2,7"]) return @"iPad Mini 1G";if ([platform isEqualToString:@"iPad3,1"]) return @"iPad 3";if ([platform isEqualToString:@"iPad3,2"]) return @"iPad 3";if ([platform isEqualToString:@"iPad3,3"]) return @"iPad 3";if ([platform isEqualToString:@"iPad3,4"]) return @"iPad 4";if ([platform isEqualToString:@"iPad3,5"]) return @"iPad 4";if ([platform isEqualToString:@"iPad3,6"]) return @"iPad 4";if ([platform isEqualToString:@"iPad4,1"]) return @"iPad Air";if ([platform isEqualToString:@"iPad4,2"]) return @"iPad Air";if ([platform isEqualToString:@"iPad4,3"]) return @"iPad Air";if ([platform isEqualToString:@"iPad4,4"]) return @"iPad Mini 2G";if ([platform isEqualToString:@"iPad4,5"]) return @"iPad Mini 2G";if ([platform isEqualToString:@"iPad4,6"]) return @"iPad Mini 2G";if ([platform isEqualToString:@"i386"]) return @"iPhone Simulator";if ([platform isEqualToString:@"x86_64"]) return @"iPhone Simulator";return platform;
}

49、長(zhǎng)按復(fù)制功能

- (void)viewDidLoad
{[self.view addGestureRecognizer:[[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(pasteBoard:)]];
}
- (void)pasteBoard:(UILongPressGestureRecognizer *)longPress {if (longPress.state == UIGestureRecognizerStateBegan) {UIPasteboard *pasteboard = [UIPasteboard generalPasteboard];pasteboard.string = @"需要復(fù)制的文本";}
}

50、cocoapods升級(jí)

在終端執(zhí)行 sudo gem install -n / usr / local / bin cocoapods --pre

51、設(shè)置啟動(dòng)頁(yè)后，依然顯示之前的

刪除app，手機(jī)重啟，重新安裝

52、判斷圖片類(lèi)型

//通過(guò)圖片Data數(shù)據(jù)第一個(gè)字節(jié) 來(lái)獲取圖片擴(kuò)展名
- (NSString *)contentTypeForImageData:(NSData *)data
{uint8_t c;[data getBytes:&c length:1];switch (c){case 0xFF:return @"jpeg";case 0x89:return @"png";case 0x47:return @"gif";case 0x49:case 0x4D:return @"tiff";case 0x52:if ([data length] < 12) {return nil;}NSString *testString = [[NSString alloc] initWithData:[data subdataWithRange:NSMakeRange(0, 12)] encoding:NSASCIIStringEncoding];if ([testString hasPrefix:@"RIFF"]&& [testString hasSuffix:@"WEBP"]){return @"webp";}return nil;}return nil;
}

53、獲取手機(jī)和app信息

NSDictionary *infoDictionary = [[NSBundle mainBundle] infoDictionary];  CFShow(infoDictionary);  
// app名稱(chēng)  NSString *app_Name = [infoDictionary objectForKey:@"CFBundleDisplayName"];  // app版本  NSString *app_Version = [infoDictionary objectForKey:@"CFBundleShortVersionString"];  // app build版本  NSString *app_build = [infoDictionary objectForKey:@"CFBundleVersion"];  //手機(jī)序列號(hào)  NSString* identifierNumber = [[UIDevice currentDevice] uniqueIdentifier];  NSLog(@"手機(jī)序列號(hào): %@",identifierNumber);  //手機(jī)別名： 用戶(hù)定義的名稱(chēng)  NSString* userPhoneName = [[UIDevice currentDevice] name];  NSLog(@"手機(jī)別名: %@", userPhoneName);  //設(shè)備名稱(chēng)  NSString* deviceName = [[UIDevice currentDevice] systemName];  NSLog(@"設(shè)備名稱(chēng): %@",deviceName );  //手機(jī)系統(tǒng)版本  NSString* phoneVersion = [[UIDevice currentDevice] systemVersion];  NSLog(@"手機(jī)系統(tǒng)版本: %@", phoneVersion);  //手機(jī)型號(hào)  NSString* phoneModel = [[UIDevice currentDevice] model];  NSLog(@"手機(jī)型號(hào): %@",phoneModel );  //地方型號(hào)  （國(guó)際化區(qū)域名稱(chēng)）  NSString* localPhoneModel = [[UIDevice currentDevice] localizedModel];  NSLog(@"國(guó)際化區(qū)域名稱(chēng): %@",localPhoneModel );  NSDictionary *infoDictionary = [[NSBundle mainBundle] infoDictionary];  // 當(dāng)前應(yīng)用名稱(chēng)  NSString *appCurName = [infoDictionary objectForKey:@"CFBundleDisplayName"];  NSLog(@"當(dāng)前應(yīng)用名稱(chēng)：%@",appCurName);  // 當(dāng)前應(yīng)用軟件版本  比如：1.0.1  NSString *appCurVersion = [infoDictionary objectForKey:@"CFBundleShortVersionString"];  NSLog(@"當(dāng)前應(yīng)用軟件版本:%@",appCurVersion);  // 當(dāng)前應(yīng)用版本號(hào)碼   int類(lèi)型  NSString *appCurVersionNum = [infoDictionary objectForKey:@"CFBundleVersion"];  NSLog(@"當(dāng)前應(yīng)用版本號(hào)碼：%@",appCurVersionNum);

54、獲取一個(gè)類(lèi)的所有屬性

id LenderClass = objc_getClass("Lender");
unsigned int outCount, i;
objc_property_t *properties = class_copyPropertyList(LenderClass, &outCount);
for (i = 0; i < outCount; i++) {objc_property_t property = properties[i];fprintf(stdout, "%s %s\n", property_getName(property), property_getAttributes(property));
}

55、image圓角

- (UIImage *)circleImage
{// NO代表透明UIGraphicsBeginImageContextWithOptions(self.size, NO, 1);// 獲得上下文CGContextRef ctx = UIGraphicsGetCurrentContext();// 添加一個(gè)圓CGRect rect = CGRectMake(0, 0, self.size.width, self.size.height);// 方形變圓形CGContextAddEllipseInRect(ctx, rect);// 裁剪CGContextClip(ctx);// 將圖片畫(huà)上去[self drawInRect:rect];UIImage *image = UIGraphicsGetImageFromCurrentImageContext();UIGraphicsEndImageContext();return image;
}

56、image拉伸

+ (UIImage *)resizableImage:(NSString *)imageName
{UIImage *image = [UIImage imageNamed:imageName];CGFloat imageW = image.size.width;CGFloat imageH = image.size.height;return [image resizableImageWithCapInsets:UIEdgeInsetsMake(imageH * 0.5, imageW * 0.5, imageH * 0.5, imageW * 0.5) resizingMode:UIImageResizingModeStretch];
}

57、JSON字符串轉(zhuǎn)字典

+ (NSDictionary *)parseJSONStringToNSDictionary:(NSString *)JSONString {NSData *JSONData = [JSONString dataUsingEncoding:NSUTF8StringEncoding];NSDictionary *responseJSON = [NSJSONSerialization JSONObjectWithData:JSONData options:NSJSONReadingMutableLeaves error:nil];return responseJSON;
}

58、身份證號(hào)驗(yàn)證

- (BOOL)validateIdentityCard {BOOL flag;if (self.length <= 0) {flag = NO;return flag;}NSString *regex2 = @"^(\\d{14}|\\d{17})(\\d|[xX])$";NSPredicate *identityCardPredicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",regex2];return [identityCardPredicate evaluateWithObject:self];
}

59、獲取設(shè)備mac地址

+ (NSString *)macAddress {int                 mib[6];size_t              len;char                *buf;unsigned char       *ptr;struct if_msghdr    *ifm;struct sockaddr_dl  *sdl;mib[0] = CTL_NET;mib[1] = AF_ROUTE;mib[2] = 0;mib[3] = AF_LINK;mib[4] = NET_RT_IFLIST;if((mib[5] = if_nametoindex("en0")) == 0) {printf("Error: if_nametoindex error\n");return NULL;}if(sysctl(mib, 6, NULL, &len, NULL, 0) < 0) {printf("Error: sysctl, take 1\n");return NULL;}if((buf = malloc(len)) == NULL) {printf("Could not allocate memory. Rrror!\n");return NULL;}if(sysctl(mib, 6, buf, &len, NULL, 0) < 0) {printf("Error: sysctl, take 2");return NULL;}ifm = (struct if_msghdr *)buf;sdl = (struct sockaddr_dl *)(ifm + 1);ptr = (unsigned char *)LLADDR(sdl);NSString *outstring = [NSString stringWithFormat:@"%02X:%02X:%02X:%02X:%02X:%02X",*ptr, *(ptr+1), *(ptr+2), *(ptr+3), *(ptr+4), *(ptr+5)];free(buf);return outstring;
}

60、導(dǎo)入自定義字體庫(kù)

1、找到你想用的字體的 ttf 格式，拖入工程
2、在工程的plist中增加一行數(shù)組，“Fonts provided by application”
3、為這個(gè)key添加一個(gè)item，value為你剛才導(dǎo)入的ttf文件名
4、直接使用即可：label.font = [UIFont fontWithName:@"你剛才導(dǎo)入的ttf文件名" size:20.0]；

61、拿到當(dāng)前正在顯示的控制器，不管是push進(jìn)去的，還是present進(jìn)去的都能拿到

- (UIViewController *)getVisibleViewControllerFrom:(UIViewController*)vc {if ([vc isKindOfClass:[UINavigationController class]]) {return [self getVisibleViewControllerFrom:[((UINavigationController*) vc) visibleViewController]];}else if ([vc isKindOfClass:[UITabBarController class]]){return [self getVisibleViewControllerFrom:[((UITabBarController*) vc) selectedViewController]];} else {if (vc.presentedViewController) {return [self getVisibleViewControllerFrom:vc.presentedViewController];} else {return vc;}}
}

62、runtime為一個(gè)類(lèi)動(dòng)態(tài)添加屬性

// 動(dòng)態(tài)添加屬性的本質(zhì)是: 讓對(duì)象的某個(gè)屬性與值產(chǎn)生關(guān)聯(lián)objc_setAssociatedObject(self, WZBPlaceholderViewKey, placeholderView, OBJC_ASSOCIATION_RETAIN_NONATOMIC);

63、獲取runtime為一個(gè)類(lèi)動(dòng)態(tài)添加的屬性

objc_getAssociatedObject(self, WZBPlaceholderViewKey);

64、KVO監(jiān)聽(tīng)某個(gè)對(duì)象的屬性

// 添加監(jiān)聽(tīng)者
[self addObserver:self forKeyPath:property options:NSKeyValueObservingOptionNew context:nil];// 當(dāng)監(jiān)聽(tīng)的屬性值變化的時(shí)候會(huì)來(lái)到這個(gè)方法
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {if ([keyPath isEqualToString:@"property"]) {[self textViewTextChange];} else {}
}

65、Reachability判斷網(wǎng)絡(luò)狀態(tài)

NetworkStatus status = [[Reachability reachabilityForInternetConnection] currentReachabilityStatus];if (status == NotReachable) {NSLog(@"當(dāng)前設(shè)備無(wú)網(wǎng)絡(luò)");}if (status == ReachableViaWiFi) {NSLog(@"當(dāng)前wifi網(wǎng)絡(luò)");}if (status == ReachableViaWWAN) {NSLog(@"當(dāng)前蜂窩移動(dòng)網(wǎng)絡(luò)");}

66、AFNetworking監(jiān)聽(tīng)網(wǎng)絡(luò)狀態(tài)

// 監(jiān)聽(tīng)網(wǎng)絡(luò)狀況AFNetworkReachabilityManager *mgr = [AFNetworkReachabilityManager sharedManager];[mgr setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) {switch (status) {case AFNetworkReachabilityStatusUnknown:break;case AFNetworkReachabilityStatusNotReachable: {[SVProgressHUD showInfoWithStatus:@"當(dāng)前設(shè)備無(wú)網(wǎng)絡(luò)"];}break;case AFNetworkReachabilityStatusReachableViaWiFi:[SVProgressHUD showInfoWithStatus:@"當(dāng)前Wi-Fi網(wǎng)絡(luò)"];break;case AFNetworkReachabilityStatusReachableViaWWAN:[SVProgressHUD showInfoWithStatus:@"當(dāng)前蜂窩移動(dòng)網(wǎng)絡(luò)"];break;
            default:break;}}];[mgr startMonitoring];

67、透明顏色不影響子視圖透明度

    [UIColor colorWithRed:<#(CGFloat)#> green:<#(CGFloat)#> blue:<#(CGFloat)#> alpha:<#(CGFloat)#>];

68、取圖片某一點(diǎn)的顏色

    if (point.x < 0 || point.y < 0) return nil;CGImageRef imageRef = self.CGImage;NSUInteger width = CGImageGetWidth(imageRef);NSUInteger height = CGImageGetHeight(imageRef);if (point.x >= width || point.y >= height) return nil;unsigned char *rawData = malloc(height * width * 4);if (!rawData) return nil;CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();NSUInteger bytesPerPixel = 4;NSUInteger bytesPerRow = bytesPerPixel * width;NSUInteger bitsPerComponent = 8;CGContextRef context = CGBitmapContextCreate(rawData,width,height,bitsPerComponent,bytesPerRow,colorSpace,kCGImageAlphaPremultipliedLast| kCGBitmapByteOrder32Big);if (!context) {free(rawData);return nil;}CGColorSpaceRelease(colorSpace);CGContextDrawImage(context, CGRectMake(0, 0, width, height), imageRef);CGContextRelease(context);int byteIndex = (bytesPerRow * point.y) + point.x * bytesPerPixel;CGFloat red   = (rawData[byteIndex]     * 1.0) / 255.0;CGFloat green = (rawData[byteIndex + 1] * 1.0) / 255.0;CGFloat blue  = (rawData[byteIndex + 2] * 1.0) / 255.0;CGFloat alpha = (rawData[byteIndex + 3] * 1.0) / 255.0;UIColor *result = nil;result = [UIColor colorWithRed:red green:green blue:blue alpha:alpha];free(rawData);return result;

69、判斷該圖片是否有透明度通道

  - (BOOL)hasAlphaChannel
{CGImageAlphaInfo alpha = CGImageGetAlphaInfo(self.CGImage);return (alpha == kCGImageAlphaFirst ||alpha == kCGImageAlphaLast ||alpha == kCGImageAlphaPremultipliedFirst ||alpha == kCGImageAlphaPremultipliedLast);
}

70、獲得灰度圖

+ (UIImage*)covertToGrayImageFromImage:(UIImage*)sourceImage
{int width = sourceImage.size.width;int height = sourceImage.size.height;CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceGray();CGContextRef context = CGBitmapContextCreate (nil,width,height,8,0,colorSpace,kCGImageAlphaNone);CGColorSpaceRelease(colorSpace);if (context == NULL) {return nil;}CGContextDrawImage(context,CGRectMake(0, 0, width, height), sourceImage.CGImage);CGImageRef contextRef = CGBitmapContextCreateImage(context);UIImage *grayImage = [UIImage imageWithCGImage:contextRef];CGContextRelease(context);CGImageRelease(contextRef);return grayImage;
}

71、根據(jù)bundle中的文件名讀取圖片

   + (UIImage *)imageWithFileName:(NSString *)name {NSString *extension = @"png";NSArray *components = [name componentsSeparatedByString:@"."];if ([components count] >= 2) {NSUInteger lastIndex = components.count - 1;extension = [components objectAtIndex:lastIndex];name = [name substringToIndex:(name.length-(extension.length+1))];}// 如果為Retina屏幕且存在對(duì)應(yīng)圖片，則返回Retina圖片，否則查找普通圖片if ([UIScreen mainScreen].scale == 2.0) {name = [name stringByAppendingString:@"@2x"];NSString *path = [[NSBundle mainBundle] pathForResource:name ofType:extension];if (path != nil) {return [UIImage imageWithContentsOfFile:path];}}if ([UIScreen mainScreen].scale == 3.0) {name = [name stringByAppendingString:@"@3x"];NSString *path = [[NSBundle mainBundle] pathForResource:name ofType:extension];if (path != nil) {return [UIImage imageWithContentsOfFile:path];}}NSString *path = [[NSBundle mainBundle] pathForResource:name ofType:extension];if (path) {return [UIImage imageWithContentsOfFile:path];}return nil;
}

72、合并兩個(gè)圖片

+ (UIImage*)mergeImage:(UIImage*)firstImage withImage:(UIImage*)secondImage {CGImageRef firstImageRef = firstImage.CGImage;CGFloat firstWidth = CGImageGetWidth(firstImageRef);CGFloat firstHeight = CGImageGetHeight(firstImageRef);CGImageRef secondImageRef = secondImage.CGImage;CGFloat secondWidth = CGImageGetWidth(secondImageRef);CGFloat secondHeight = CGImageGetHeight(secondImageRef);CGSize mergedSize = CGSizeMake(MAX(firstWidth, secondWidth), MAX(firstHeight, secondHeight));UIGraphicsBeginImageContext(mergedSize);[firstImage drawInRect:CGRectMake(0, 0, firstWidth, firstHeight)];[secondImage drawInRect:CGRectMake(0, 0, secondWidth, secondHeight)];UIImage *image = UIGraphicsGetImageFromCurrentImageContext();UIGraphicsEndImageContext();return image;
}

73、根據(jù)bundle中的圖片名創(chuàng)建imageview

+ (id)imageViewWithImageNamed:(NSString*)imageName
{return [[UIImageView alloc] initWithImage:[UIImage imageNamed:imageName]];
}

74、為imageView添加倒影

    CGRect frame = self.frame;frame.origin.y += (frame.size.height + 1);UIImageView *reflectionImageView = [[UIImageView alloc] initWithFrame:frame];self.clipsToBounds = TRUE;reflectionImageView.contentMode = self.contentMode;[reflectionImageView setImage:self.image];reflectionImageView.transform = CGAffineTransformMakeScale(1.0, -1.0);CALayer *reflectionLayer = [reflectionImageView layer];CAGradientLayer *gradientLayer = [CAGradientLayer layer];gradientLayer.bounds = reflectionLayer.bounds;gradientLayer.position = CGPointMake(reflectionLayer.bounds.size.width / 2, reflectionLayer.bounds.size.height * 0.5);gradientLayer.colors = [NSArray arrayWithObjects:(id)[[UIColor clearColor] CGColor],(id)[[UIColor colorWithRed:1.0 green:1.0 blue:1.0 alpha:0.3] CGColor], nil];gradientLayer.startPoint = CGPointMake(0.5,0.5);gradientLayer.endPoint = CGPointMake(0.5,1.0);reflectionLayer.mask = gradientLayer;[self.superview addSubview:reflectionImageView];

75、畫(huà)水印

// 畫(huà)水印
- (void) setImage:(UIImage *)image withWaterMark:(UIImage *)mark inRect:(CGRect)rect
{if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 4.0){UIGraphicsBeginImageContextWithOptions(self.frame.size, NO, 0.0);}//原圖[image drawInRect:self.bounds];//水印圖;UIImage *newPic = UIGraphicsGetImageFromCurrentImageContext();UIGraphicsEndImageContext();self.image = newPic;
}

76、讓label的文字內(nèi)容顯示在左上／右上／左下／右下／中心頂／中心底部

自定義UILabel
// 重寫(xiě)label的textRectForBounds方法
- (CGRect)textRectForBounds:(CGRect)bounds limitedToNumberOfLines:(NSInteger)numberOfLines {CGRect rect = [super textRectForBounds:bounds limitedToNumberOfLines:numberOfLines];switch (self.textAlignmentType) {case WZBTextAlignmentTypeLeftTop: {rect.origin = bounds.origin;}break;case WZBTextAlignmentTypeRightTop: {rect.origin = CGPointMake(CGRectGetMaxX(bounds) - rect.size.width, bounds.origin.y);}break;case WZBTextAlignmentTypeLeftBottom: {rect.origin = CGPointMake(bounds.origin.x, CGRectGetMaxY(bounds) - rect.size.height);}break;case WZBTextAlignmentTypeRightBottom: {rect.origin = CGPointMake(CGRectGetMaxX(bounds) - rect.size.width, CGRectGetMaxY(bounds) - rect.size.height);}break;case WZBTextAlignmentTypeTopCenter: {rect.origin = CGPointMake((CGRectGetWidth(bounds) - CGRectGetWidth(rect)) / 2, CGRectGetMaxY(bounds) - rect.origin.y);}break;case WZBTextAlignmentTypeBottomCenter: {rect.origin = CGPointMake((CGRectGetWidth(bounds) - CGRectGetWidth(rect)) / 2, CGRectGetMaxY(bounds) - CGRectGetMaxY(bounds) - rect.size.height);}break;case WZBTextAlignmentTypeLeft: {rect.origin = CGPointMake(0, rect.origin.y);}break;case WZBTextAlignmentTypeRight: {rect.origin = CGPointMake(rect.origin.x, 0);}break;case WZBTextAlignmentTypeCenter: {rect.origin = CGPointMake((CGRectGetWidth(bounds) - CGRectGetWidth(rect)) / 2, (CGRectGetHeight(bounds) - CGRectGetHeight(rect)) / 2);}break;default:break;}return rect;
}
- (void)drawTextInRect:(CGRect)rect {CGRect textRect = [self textRectForBounds:rect limitedToNumberOfLines:self.numberOfLines];[super drawTextInRect:textRect];
}

77、scrollView上的輸入框，鍵盤(pán)擋住的問(wèn)題

推薦用IQKeyboardManager這個(gè)框架！
手動(dòng)解決如下
1、監(jiān)聽(tīng)鍵盤(pán)彈出／消失的通知
2、在通知中加入代碼：
NSDictionary* info = [aNotification userInfo];
CGRect keyPadFrame=[[UIApplication sharedApplication].keyWindow convertRect:[ CGRectValue] fromView:self.view];
CGSize kbSize =keyPadFrame.size;
CGRect activeRect=[self.view convertRect:activeField.frame fromView:activeField.superview];
CGRect aRect = self.view.bounds;
aRect.size.height -= (kbSize.height);CGPoint origin =  activeRect.origin;
origin.y -= backScrollView.contentOffset.y;
if (!CGRectContainsPoint(aRect, origin)) {CGPoint scrollPoint = CGPointMake(0.0,CGRectGetMaxY(activeRect)-(aRect.size.height));[backScrollView setContentOffset:scrollPoint animated:YES];
}

78、frame布局的cell動(dòng)態(tài)高度

這種通常在你的模型中添加一個(gè)輔助屬性cellHeight，在模型中重寫(xiě)這個(gè)屬性的get方法，根據(jù)你的布局和模型中的其他屬性值計(jì)算出總高度。最后在tableView：heightForRow方法中，根據(jù)indexPath找出對(duì)應(yīng)的模型，返回這個(gè)高度即可。

79、AutoLayout布局的cell動(dòng)態(tài)高度

// 1、設(shè)置tableView的屬性
self.tableView.rowHeight = UITableViewAutomaticDimension;
self.tableView.estimatedRowHeight = 44.0; // 這個(gè)屬性非0，估計(jì)cell高度

// 2、至上而下設(shè)置cell的約束，注意，上下左右最好都要頂?shù)絚ell的四周

cell

80、使用performSelector:調(diào)用函數(shù)，內(nèi)存泄漏問(wèn)題

當(dāng)我們?cè)陂_(kāi)發(fā)中使用[obj performSelector:NSSelectorFromString(@"aMethod")];這類(lèi)方法時(shí)可能會(huì)收到一個(gè)警告"performSelector may cause a leak because its selector is unknown".
是因?yàn)榫幾g器不清楚這個(gè)對(duì)象能不能相應(yīng)這個(gè)方法，如果不能，則是不安全的，而且編譯器也不清楚該怎么處理這個(gè)方法的返回值！

使用以下代碼調(diào)用即可：
if (! obj) { return; }
SEL selector = NSSelectorFromString(@"aMethod");
IMP imp = [obj methodForSelector:selector];
void (*func)(id, SEL) = (void *)imp;
func(obj, selector);或者：
SEL selector = NSSelectorFromString(@"aMethod");
((void (*)(id, SEL))[obj methodForSelector:selector])(obj, selector);

81、一個(gè)字符串是否包含另一個(gè)字符串

// 方法1
if ([str1 containsString:str2]) {NSLog(@"str1包含str2");} else {NSLog(@"str1不包含str2");}// 方法2
if ([str1 rangeOfString: str2].location == NSNotFound) {NSLog(@"str1不包含str2");} else {NSLog(@"str1包含str2");}

82、cell去除選中效果

cell.selectionStyle = UITableViewCellSelectionStyleNone;

83、cell點(diǎn)按效果

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {[tableView deselectRowAtIndexPath:indexPath animated:YES];
}

84、當(dāng)刪除一個(gè)從xib拖出來(lái)的屬性時(shí)，一定記得把xib中對(duì)應(yīng)的線也刪掉，不然會(huì)報(bào)類(lèi)似[<ViewController 0x7fea6ed05980> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key的crash

點(diǎn)擊這個(gè)叉號(hào)刪除

85、真機(jī)測(cè)試的時(shí)候報(bào)錯(cuò)：Could not launch "你的 App"，process launch failed: Security

因?yàn)槟愕腶pp沒(méi)有上線，iOS9開(kāi)始，需要手動(dòng)信任Xcode生成的描述文件，打開(kāi)手機(jī)設(shè)置->通用->描述文件->點(diǎn)擊你的app的描述文件->點(diǎn)擊信任

86、真機(jī)測(cè)試的時(shí)候報(bào)錯(cuò)：Could not find Developer Disk Image

這是因?yàn)槟愕脑O(shè)備系統(tǒng)版本大于Xcode能兼容的系統(tǒng)版本，比如你的設(shè)備是iOS10.3，而Xcode版本是8.2（Xcode8.2最大兼容iOS10.2），就會(huì)報(bào)這個(gè)錯(cuò)誤。解決辦法就是升級(jí)Xcode！

87、UITextView沒(méi)有placeholder的問(wèn)題？

網(wǎng)上有很多此類(lèi)自定義控件，也可以參考下我寫(xiě)的一個(gè)UITextView分類(lèi) UITextView-WZB

88、移除字符串中的空格和換行

+ (NSString *)removeSpaceAndNewline:(NSString *)str {NSString *temp = [str stringByReplacingOccurrencesOfString:@" " withString:@""];temp = [temp stringByReplacingOccurrencesOfString:@"\r" withString:@""];temp = [temp stringByReplacingOccurrencesOfString:@"\n" withString:@""];return temp;
}

89、判斷字符串中是否有空格

+ (BOOL)isBlank:(NSString *)str {NSRange _range = [str rangeOfString:@" "];if (_range.location != NSNotFound) {//有空格return YES;} else {//沒(méi)有空格return NO;}
}

90、獲取一個(gè)視頻的第一幀圖片

    NSURL *url = [NSURL URLWithString:filepath];AVURLAsset *asset1 = [[AVURLAsset alloc] initWithURL:url options:nil];AVAssetImageGenerator *generate1 = [[AVAssetImageGenerator alloc] initWithAsset:asset1];generate1.appliesPreferredTrackTransform = YES;NSError *err = NULL;CMTime time = CMTimeMake(1, 2);CGImageRef oneRef = [generate1 copyCGImageAtTime:time actualTime:NULL error:&err];UIImage *one = [[UIImage alloc] initWithCGImage:oneRef];return one;

91、獲取視頻的時(shí)長(zhǎng)

+ (NSInteger)getVideoTimeByUrlString:(NSString *)urlString {NSURL *videoUrl = [NSURL URLWithString:urlString];AVURLAsset *avUrl = [AVURLAsset assetWithURL:videoUrl];CMTime time = [avUrl duration];int seconds = ceil(time.value/time.timescale);return seconds;
}

92、字符串是否為空

+ (BOOL)isEqualToNil:(NSString *)str {return str.length <= 0 || [str isEqualToString:@""] || !str;
}

93、將app上傳到App Store的時(shí)候通常會(huì)遇到這個(gè)問(wèn)題

try again

很多人說(shuō)這事蘋(píng)果爸爸服務(wù)器問(wèn)題，重復(fù)嘗試幾次，總會(huì)成功的！
但是經(jīng)過(guò)嘗試發(fā)現(xiàn)如果使用Application Loader上傳成功率就非常高，所以還是推薦把ipa文件導(dǎo)出直接用Application Loader上傳。
如果Application Loader也不行，需要檢查下自己的網(wǎng)絡(luò)，有時(shí)候vpn也會(huì)提高速度。

94、當(dāng)tableView占不滿一屏?xí)r，去除下邊多余的單元格

self.tableView.tableHeaderView = [UIView new];
self.tableView.tableFooterView = [UIView new];

95、isKindOfClass和isMemberOfClass的區(qū)別

isKindOfClass可以判斷某個(gè)對(duì)象是否屬于某個(gè)類(lèi)，或者這個(gè)類(lèi)的子類(lèi)。
isMemberOfClass更加精準(zhǔn)，它只能判斷這個(gè)對(duì)象類(lèi)型是否為這個(gè)類(lèi)(不能判斷子類(lèi))

96、__block

當(dāng)一個(gè)局部變量需要在block里改變時(shí)，需要在定義時(shí)加上__block修飾，具體請(qǐng)看官方文檔 http://developer.apple.com/library/ios/documentation/cocoa/Conceptual/Blocks/Articles/bxVariables.html#//apple_ref/doc/uid/TP40007502-CH6-SW6

97、-[ViewController aMethod:]: unrecognized selector sent to instance 0x7fe91e607fb0

這是一個(gè)經(jīng)典錯(cuò)誤，ViewController不能響應(yīng)aMethod這個(gè)方法，錯(cuò)誤原因可能viewController文件中沒(méi)有實(shí)現(xiàn)aMethod這個(gè)方法

98、UITableView (<UITableView: 0x7ff19b027000; >) failed to obtain a cell from its dataSource (<ViewController: 0x7ff19a507520>)

這個(gè)錯(cuò)誤原因是tableView的代理方法-tableView:cellForRowAtIndexPath:需要返回一個(gè)UITableViewCell,而你返回了一個(gè)nil。另外這個(gè)地方返回值不是UITableViewCell類(lèi)型也會(huì)導(dǎo)致崩潰

99、約束如何做UIView動(dòng)畫(huà)？

1、把需要改的約束Constraint拖條線出來(lái)，成為屬性
2、在需要?jiǎng)赢?huà)的地方加入代碼，改變此屬性的constant屬性
3、開(kāi)始做UIView動(dòng)畫(huà)，動(dòng)畫(huà)里邊調(diào)用layoutIfNeeded方法@property (weak, nonatomic) IBOutlet NSLayoutConstraint *buttonTopConstraint;
self.buttonTopConstraint.constant = 100;[UIView animateWithDuration:.5 animations:^{[self.view layoutIfNeeded];}];

100、從NSURL中拿到鏈接字符串

NSString *urlString = myURL.absoluteString;

101、將tableView滾動(dòng)到頂部

[tableView setContentOffset:CGPointZero animated:YES];
或者
[tableView scrollRectToVisible:CGRectMake(0, 0, 1, 1) animated:YES];

102、如果用addTarget:action:forControlEvents:方法為一個(gè)button添加了很多點(diǎn)擊事件，在某個(gè)時(shí)刻想一次刪除怎么辦？只需要調(diào)用下邊這句代碼

[youButton removeTarget:nil action:nil forControlEvents:UIControlEventAllEvents];

103、某個(gè)字體的高度

font.lineHeight;

104、刪除某個(gè)view所有的子視圖

[[someView subviews]makeObjectsPerformSelector:@selector(removeFromSuperview)];

105、刪除NSUserDefaults所有記錄

//方法一NSString *appDomain = [[NSBundle mainBundle] bundleIdentifier];[[NSUserDefaults standardUserDefaults] removePersistentDomainForName:appDomain];   //方法二  
- (void)resetDefaults {   NSUserDefaults * defs = [NSUserDefaults standardUserDefaults];NSDictionary * dict = [defs dictionaryRepresentation];for (id key in dict) {[defs removeObjectForKey:key];}[defs synchronize];}
// 方法三
[[NSUserDefaults standardUserDefaults] setPersistentDomain:[NSDictionary dictionary] forName:[[NSBundle mainBundle] bundleIdentifier]];

106、禁用系統(tǒng)滑動(dòng)返回功能

- (void)viewDidAppear:(BOOL)animated
{[super viewDidAppear:animated];
if ([self.navigationController respondsToSelector:@selector(interactivePopGestureRecognizer)]) {self.navigationController.interactivePopGestureRecognizer.delegate = self;}
}- (void)viewWillDisappear:(BOOL)animated {[super viewWillDisappear:animated];if ([self.navigationController respondsToSelector:@selector(interactivePopGestureRecognizer)]) {self.navigationController.interactivePopGestureRecognizer.delegate = nil;}
}
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
{return NO;
}

107、模擬器報(bào)錯(cuò)

模擬器報(bào)錯(cuò)

解決辦法：
打開(kāi)模擬器->Simulator->Reset Content and Settings...
如果不行，就重啟試試！

108、自定義cell選中背景顏色

UIView *bgColorView = [[UIView alloc] init];
bgColorView.backgroundColor = [UIColor redColor];
[cell setSelectedBackgroundView:bgColorView];

109、UILabel設(shè)置內(nèi)邊距

子類(lèi)化UILabel，重寫(xiě)drawTextInRect方法
- (void)drawTextInRect:(CGRect)rect {// 邊距，上左下右UIEdgeInsets insets = {0, 5, 0, 5};[super drawTextInRect:UIEdgeInsetsInsetRect(rect, insets)];
}

110、UILabel設(shè)置文字描邊

子類(lèi)化UILabel，重寫(xiě)drawTextInRect方法
- (void)drawTextInRect:(CGRect)rect
{CGContextRef c = UIGraphicsGetCurrentContext();// 設(shè)置描邊寬度CGContextSetLineWidth(c, 1);CGContextSetLineJoin(c, kCGLineJoinRound);CGContextSetTextDrawingMode(c, kCGTextStroke);// 描邊顏色self.textColor = [UIColor redColor];[super drawTextInRect:rect];// 文本顏色self.textColor = [UIColor yellowColor];CGContextSetTextDrawingMode(c, kCGTextFill);[super drawTextInRect:rect];
}

111、使用模擬器截圖

快捷鍵command + s
或者File->Save Screen Shot

112、scrollView滾動(dòng)到最下邊

CGPoint bottomOffset = CGPointMake(0, scrollView.contentSize.height - scrollView.bounds.size.height);
[scrollView setContentOffset:bottomOffset animated:YES];

113、UIView背景顏色漸變

    UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 100)];[self.view addSubview:view];CAGradientLayer *gradient = [CAGradientLayer layer];gradient.frame = view.bounds;gradient.colors = [NSArray arrayWithObjects:(id)[[UIColor blackColor] CGColor], (id)[[UIColor whiteColor] CGColor], nil];[view.layer insertSublayer:gradient atIndex:0];

114、停止UIView動(dòng)畫(huà)

[yourView.layer removeAllAnimations]

115、為UIView某個(gè)角添加圓角

// 左上角和右下角添加圓角
UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:view.bounds byRoundingCorners:(UIRectCornerTopLeft | UIRectCornerBottomRight) cornerRadii:CGSizeMake(20, 20)];CAShapeLayer *maskLayer = [CAShapeLayer layer];maskLayer.frame = view.bounds;maskLayer.path = maskPath.CGPath;view.layer.mask = maskLayer;

116、刪除Xcode Derived data緩存數(shù)據(jù)

依次點(diǎn)擊Xcode -> Preferences -> location，然后點(diǎn)擊 Derived data路徑后到小箭頭，刪除這個(gè)文件夾下的數(shù)據(jù)就可以了，如圖

Xcode Derived data

117、將一個(gè)view放置在其兄弟視圖的最上面

[parentView bringSubviewToFront:yourView]

118、將一個(gè)view放置在其兄弟視圖的最下面

[parentView sendSubviewToBack:yourView]

119、讓手機(jī)震動(dòng)一下

倒入框架
#import <AudioToolbox/AudioToolbox.h>
AudioServicesPlayAlertSound(kSystemSoundID_Vibrate);
或者
AudioServicesPlaySystemSound(kSystemSoundID_Vibrate);

120、layoutSubviews方法什么時(shí)候調(diào)用？

1、init方法不會(huì)調(diào)用
2、addSubview方法等時(shí)候會(huì)調(diào)用
3、bounds改變的時(shí)候調(diào)用
4、scrollView滾動(dòng)的時(shí)候會(huì)調(diào)用scrollView的layoutSubviews方法(所以不建議在scrollView的layoutSubviews方法中做復(fù)雜邏輯)
5、旋轉(zhuǎn)設(shè)備的時(shí)候調(diào)用
6、子視圖被移除的時(shí)候調(diào)用
參考請(qǐng)看：http://blog.logichigh.com/2011/03/16/when-does-layoutsubviews-get-called/

121、讓UILabel在指定的地方換行

// 換行符為\n,在需要換行的地方加上這個(gè)符號(hào)即可，如 
label.numberOfLines = 0;
label.text = @"此處\n換行";

122、搖一搖功能

1、打開(kāi)搖一搖功能[UIApplication sharedApplication].applicationSupportsShakeToEdit = YES;
2、讓需要搖動(dòng)的控制器成為第一響應(yīng)者
[self becomeFirstResponder];
3、實(shí)現(xiàn)以下方法// 開(kāi)始搖動(dòng)
- (void)motionBegan:(UIEventSubtype)motion withEvent:(UIEvent *)event
// 取消搖動(dòng)
- (void)motionCancelled:(UIEventSubtype)motion withEvent:(UIEvent *)event
// 搖動(dòng)結(jié)束
- (void)motionEnded:(UIEventSubtype)motion withEvent:(UIEvent *)event

123、獲取圖片大小

CGFloat imageWidth = image.size.width;CGFloat imageHeight = imageWidth * image.scale;

124、獲取view的坐標(biāo)在整個(gè)window上的位置

// v上的(0, 0)點(diǎn)在toView上的位置
CGPoint point = [v convertPoint:CGPointMake(0, 0) toView:[UIApplication sharedApplication].windows.lastObject];
或者
CGPoint point = [v.superview convertPoint:v.frame.origin toView:[UIApplication sharedApplication].windows.lastObject];

125、提交App Store審核程序限制

您的應(yīng)用程序的未壓縮大小必須小于4GB。每個(gè)Mach-O可執(zhí)行文件（例如app_name.app/app_name）不能超過(guò)這些限制：
對(duì)于MinimumOSVersion小于7.0的應(yīng)用程序：TEXT二進(jìn)制文件中所有部分的總數(shù)最多為80 MB 。
對(duì)于MinimumOSVersion7.x到8.x的應(yīng)用程序：TEXT對(duì)于二進(jìn)制文件中每個(gè)體系結(jié)構(gòu)片段的每個(gè)片段，最大為60 MB 。
對(duì)于MinimumOSVersion9.0或更高版本的應(yīng)用程序：__TEXT二進(jìn)制文件中所有部分的總數(shù)最多為500 MB 。參閱：iTunes Connect開(kāi)發(fā)者指南

126、修改UISegmentedControl的字體大小

[segment setTitleTextAttributes:@{NSFontAttributeName : [UIFont systemFontOfSize:15.0f]} forState:UIControlStateNormal];

127、在非ViewController的地方彈出UIAlertController對(duì)話框

//  最好抽成一個(gè)分類(lèi)
UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"Title" message:@"message" preferredStyle:UIAlertControllerStyleAlert];
//...
id rootViewController = [UIApplication sharedApplication].delegate.window.rootViewController;
if([rootViewController isKindOfClass:[UINavigationController class]])
{rootViewController = ((UINavigationController *)rootViewController).viewControllers.firstObject;
}
if([rootViewController isKindOfClass:[UITabBarController class]])
{rootViewController = ((UITabBarController *)rootViewController).selectedViewController;
}
[rootViewController presentViewController:alertController animated:YES completion:nil];

128、獲取一個(gè)view所屬的控制器

// view分類(lèi)方法
- (UIViewController *)belongViewController {for (UIView *next = [self superview]; next; next = next.superview) {UIResponder* nextResponder = [next nextResponder];if ([nextResponder isKindOfClass:[UIViewController class]]) {return (UIViewController *)nextResponder;}}return nil;
}

129、UIImage和base64互轉(zhuǎn)

// view分類(lèi)方法
- (NSString *)encodeToBase64String:(UIImage *)image {return [UIImagePNGRepresentation(image) base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
}- (UIImage *)decodeBase64ToImage:(NSString *)strEncodeData {NSData *data = [[NSData alloc]initWithBase64EncodedString:strEncodeData options:NSDataBase64DecodingIgnoreUnknownCharacters];return [UIImage imageWithData:data];
}

130、UIWebView設(shè)置背景透明

[webView setBackgroundColor:[UIColor clearColor]];
[webView setOpaque:NO];

131、判斷NSDate是不是今天

NSDateComponents *otherDay = [[NSCalendar currentCalendar] components:NSCalendarUnitEra | NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay fromDate:aDate];
NSDateComponents *today = [[NSCalendar currentCalendar] components:NSCalendarUnitEra | NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay fromDate:[NSDate date]];
if([today day] == [otherDay day] &&[today month] == [otherDay month] &&[today year] == [otherDay year] &&[today era] == [otherDay era]) {// 是今天
}

132、設(shè)置tableView分割線顏色

[self.tableView setSeparatorColor:[UIColor myColor]];

133、設(shè)置屏幕方向

 NSNumber *orientationTarget = [NSNumber numberWithInt:UIInterfaceOrientationLandscapeLeft];
[[UIDevice currentDevice] setValue:orientationTarget forKey:@"orientation"];
[UIViewController attemptRotationToDeviceOrientation];

134、比較兩個(gè)顏色是否相等

- (BOOL)isEqualToColor:(UIColor *)otherColor {CGColorSpaceRef colorSpaceRGB = CGColorSpaceCreateDeviceRGB();UIColor *(^convertColorToRGBSpace)(UIColor*) = ^(UIColor *color) {if (CGColorSpaceGetModel(CGColorGetColorSpace(color.CGColor)) == kCGColorSpaceModelMonochrome) {const CGFloat *oldComponents = CGColorGetComponents(color.CGColor);CGFloat components[4] = {oldComponents[0], oldComponents[0], oldComponents[0], oldComponents[1]};CGColorRef colorRef = CGColorCreate( colorSpaceRGB, components );UIColor *color = [UIColor colorWithCGColor:colorRef];CGColorRelease(colorRef);return color;            } elsereturn color;};UIColor *selfColor = convertColorToRGBSpace(self);otherColor = convertColorToRGBSpace(otherColor);CGColorSpaceRelease(colorSpaceRGB);return [selfColor isEqual:otherColor];
}

135、tableViewCell分割線頂?shù)筋^

- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath {[cell setSeparatorInset:UIEdgeInsetsZero];[cell setLayoutMargins:UIEdgeInsetsZero];cell.preservesSuperviewLayoutMargins = NO;
}- (void)viewDidLayoutSubviews {[self.tableView setSeparatorInset:UIEdgeInsetsZero];[self.tableView setLayoutMargins:UIEdgeInsetsZero];
}

136、不讓控制器的view隨著控制器的xib拉伸或壓縮

self.view.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;

137、cocoaPods報(bào)錯(cuò) : [!] Unable to add a source with url `https://github.com/CocoaPods/Specs.git` named`master-1`.

You can try adding it manually in ~/.cocoapods/repos or via pod repo add.

解決方法：這是因?yàn)殡娔X里安裝了另外一個(gè)Xcode導(dǎo)致cocoapods找不到路徑了
在終端執(zhí)行 sudo xcode-select -switch /Applications/Xcode.app 即可

138、安裝cocoapods的時(shí)候出現(xiàn) ERROR: While executing gem ... (Errno::EPERM)

Operation not permitted - /usr/bin/pod

解決辦法：直接在終端執(zhí)行 sudo gem install -n /usr/local/bin cocoapods

139、在狀態(tài)欄增加網(wǎng)絡(luò)請(qǐng)求的菊花，類(lèi)似safari加載網(wǎng)頁(yè)的時(shí)候狀態(tài)欄菊花

[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;

140、檢查一個(gè)rect是否包含一個(gè)point

// point是否在rect內(nèi)
BOOL isContains = CGRectContainsPoint(rect, point);

141、在指定的寬度下，讓UILabel自動(dòng)設(shè)置最佳font

label.adjustsFontSizeToFitWidth = YES;

142、將一個(gè)image保存在相冊(cè)中

UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil);或者
#import <Photos/Photos.h>
[[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{PHAssetChangeRequest *changeRequest = [PHAssetChangeRequest creationRequestForAssetFromImage:image];changeRequest.creationDate          = [NSDate date];} completionHandler:^(BOOL success, NSError *error) {if (success) {NSLog(@"successfully saved");}else {NSLog(@"error saving to photos: %@", error);}}];

143、修改cell.imageView的大小

UIImage *icon = [UIImage imageNamed:@""];
CGSize itemSize = CGSizeMake(30, 30);
UIGraphicsBeginImageContextWithOptions(itemSize, NO ,0.0);
CGRect imageRect = CGRectMake(0.0, 0.0, itemSize.width, itemSize.height);
[icon drawInRect:imageRect];
cell.imageView.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

144、為一個(gè)view添加虛線邊框

 CAShapeLayer *border = [CAShapeLayer layer];border.strokeColor = [UIColor colorWithRed:67/255.0f green:37/255.0f blue:83/255.0f alpha:1].CGColor;border.fillColor = nil;border.lineDashPattern = @[@4, @2];border.path = [UIBezierPath bezierPathWithRect:view.bounds].CGPath;
    border.frame = view.bounds;
    [view.layer addSublayer:border];

145、UITextView中打開(kāi)或禁用復(fù)制，剪切，選擇，全選等功能

// 繼承UITextView重寫(xiě)這個(gè)方法
- (BOOL)canPerformAction:(SEL)action withSender:(id)sender
{
// 返回NO為禁用，YES為開(kāi)啟// 粘貼if (action == @selector(paste:)) return NO;// 剪切if (action == @selector(cut:)) return NO;// 復(fù)制if (action == @selector(copy:)) return NO;// 選擇if (action == @selector(select:)) return NO;// 選中全部if (action == @selector(selectAll:)) return NO;// 刪除if (action == @selector(delete:)) return NO;// 分享if (action == @selector(share)) return NO;return [super canPerformAction:action withSender:sender];
}

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