淘汰掉了ASIHTTPRequest和MKNetworkit，AFNetworking完美勝出

起初

新建一個(gè)工程HelloWorld，你想在這個(gè)工程中通過pod來集成使用第三方庫AFNetworking。

使用終端進(jìn)入工程根目錄，然后編輯Podfile：

vim Podfile

【這里你也許會(huì)遇到一個(gè)問題終端左下角會(huì)提示E353：Nothing in register，不要慌，這并不是什么問題，而是自己操作錯(cuò)誤，這時(shí)候只要按【i】或者【a】進(jìn)入vi的插入模式就可以編輯了】

這里普及一下vi的工作模式：

1、命令行模式：用光標(biāo)在字符之間來回移動(dòng)，進(jìn)行刪除、復(fù)制、移動(dòng)字符等操作，按【i】或者【a】進(jìn)入插入模式，按【：】（冒號(hào)）進(jìn)入末行模式；

2、插入模式：輸入你要編輯的內(nèi)容，按【esc】返回命令行模式，按【:】（冒號(hào)）進(jìn)入末行模式；

3、末行模式：保存文件或者退出vi，輸入【wq】存盤并退出vi，輸入【q！】不保存強(qiáng)制退出vi，輸入【w:filename】將文件保存為制定的文件名。

結(jié)束上述Podfile編輯后，在終端運(yùn)行

pod install

【 相關(guān)命令`pod repo update` or with `pod install --repo-update`】

了解

AFNetworking框架由會(huì)話（NSURLSeeion）、網(wǎng)絡(luò)監(jiān)聽模塊（Reachability）、網(wǎng)絡(luò)安全模塊（Security）、請(qǐng)求序列化（Serialization）、響應(yīng)序列化（Serialization）和UIKit集成模塊（UIKit）構(gòu)成

如圖：

庫中最核心的類是AFURLSessionManager，使用頻率最高的是其子類AFHTTPSessionManager，在該類中包含了負(fù)責(zé)請(qǐng)求序列化的AFURLRequestSerialization和響應(yīng)序列化AFURLResponseSerializer，AFURLSessionManager還提供了會(huì)話模塊NSURLSession、保證網(wǎng)絡(luò)安全的AFSecurityPolicy、網(wǎng)絡(luò)監(jiān)聽的AFNetworkReachabilityManager。

如圖:

使用

首先在頭部導(dǎo)入#import <AFNetworking/AFNetworking.h>

寫個(gè)get請(qǐng)求

// 實(shí)現(xiàn)一個(gè)get請(qǐng)求 -(void)makeGetRequest{AFHTTPSessionManager *sessionManager = [AFHTTPSessionManager manager];NSDictionary *headerDic = [NSDictionary dictionaryWithObjectsAndKeys:@"application/json",@"Content-Type", nil];[sessionManager GET:@"http://wna.test.com/app" parameters:nil headers:headerDic progress:^(NSProgress * _Nonnull downloadProgress) {} success:^(NSURLSessionDataTask * _Nonnull task, id _Nullable responseObject) {NSLog(@"接口請(qǐng)求成功-- %@",responseObject);} failure:^(NSURLSessionDataTask * _Nullable task, NSError * _Nonnull error) {NSLog(@"接口請(qǐng)求失敗-- %@",error);}]; }

寫個(gè)post請(qǐng)求

// 實(shí)現(xiàn)一個(gè)post請(qǐng)求 - (void)makePostRequest{AFHTTPSessionManager *sessionManager = [AFHTTPSessionManager manager];NSDictionary *headerDic = @{@"nbp-app-name":@"dog",@"Content-Type":@"application/json",};NSDictionary *parames = @{@"methodType":@"GET",@"moduleName":@"app-product",@"url":@"product/new_product_list",};[sessionManager POST:@"http://wna.test.com/app" parameters:parames headers:headerDic progress:^(NSProgress * _Nonnull uploadProgress) {} success:^(NSURLSessionDataTask * _Nonnull task, id _Nullable responseObject) {NSData *tempDisplay = [NSJSONSerialization dataWithJSONObject:responseObject options:NSJSONWritingPrettyPrinted error:nil];NSString *result = [[NSString alloc] initWithData:tempDisplay encoding:NSUTF8StringEncoding];NSLog(@"接口請(qǐng)求成功-- %@",result);} failure:^(NSURLSessionDataTask * _Nullable task, NSError * _Nonnull error) {NSLog(@"接口請(qǐng)求失敗-- %@",error);}]; }

方法的逐級(jí)調(diào)用

get方法的源碼：

- (NSURLSessionDataTask *)GET:(NSString *)URLStringparameters:(nullable id)parametersheaders:(nullable NSDictionary <NSString *, NSString *> *)headersprogress:(nullable void (^)(NSProgress * _Nonnull))downloadProgresssuccess:(nullable void (^)(NSURLSessionDataTask * _Nonnull, id _Nullable))successfailure:(nullable void (^)(NSURLSessionDataTask * _Nullable, NSError * _Nonnull))failure {NSURLSessionDataTask *dataTask = [self dataTaskWithHTTPMethod:@"GET"URLString:URLStringparameters:parametersheaders:headersuploadProgress:nildownloadProgress:downloadProgresssuccess:successfailure:failure];[dataTask resume];return dataTask; }

入?yún)⒂姓?qǐng)求的URL，參數(shù)，請(qǐng)求頭，進(jìn)度Block，成功Block和失敗Block。在這個(gè)方法中初始化了一個(gè)NSURLSessionDataTask的類,NSURLSessionDataTask繼承自NSURLSessionTask，NSURLSessionDataTask不提供NSURLSessionTask的任何附加功能，他的存在是為了區(qū)別于上載NSURLSessionUploadTask和下載NSURLSessionDownloadTask。

繼續(xù)往下看

- (NSURLSessionDataTask *)dataTaskWithHTTPMethod:(NSString *)methodURLString:(NSString *)URLStringparameters:(nullable id)parametersheaders:(nullable NSDictionary <NSString *, NSString *> *)headersuploadProgress:(nullable void (^)(NSProgress *uploadProgress)) uploadProgressdownloadProgress:(nullable void (^)(NSProgress *downloadProgress)) downloadProgresssuccess:(nullable void (^)(NSURLSessionDataTask *task, id _Nullable responseObject))successfailure:(nullable void (^)(NSURLSessionDataTask * _Nullable task, NSError *error))failure {NSError *serializationError = nil;NSMutableURLRequest *request = [self.requestSerializer requestWithMethod:method URLString:[[NSURL URLWithString:URLString relativeToURL:self.baseURL] absoluteString] parameters:parameters error:&serializationError];for (NSString *headerField in headers.keyEnumerator) {[request setValue:headers[headerField] forHTTPHeaderField:headerField];}if (serializationError) {if (failure) {dispatch_async(self.completionQueue ?: dispatch_get_main_queue(), ^{failure(nil, serializationError);});}return nil;}__block NSURLSessionDataTask *dataTask = nil;dataTask = [self dataTaskWithRequest:requestuploadProgress:uploadProgressdownloadProgress:downloadProgresscompletionHandler:^(NSURLResponse * __unused response, id responseObject, NSError *error) {if (error) {if (failure) {failure(dataTask, error);}} else {if (success) {success(dataTask, responseObject);}}}];return dataTask; }

在這個(gè)方法的實(shí)現(xiàn)里主要做了兩個(gè)事情：

實(shí)例化NSMutableURLRequest對(duì)象

實(shí)例化NSURLSessionDataTask對(duì)象，并返回

在這個(gè)方法里是通過一個(gè)實(shí)現(xiàn)了AFURLRequestSerialization協(xié)議的請(qǐng)求序列化實(shí)例對(duì)象AFHTTPRequestSerializer來調(diào)用其實(shí)例方法得到一個(gè)NSMutableURLRequest對(duì)象。

- (nullable NSMutableURLRequest *)requestWithMethod:(NSString *)methodURLString:(NSString *)URLStringparameters:(nullable id)parameterserror:(NSError * _Nullable __autoreleasing *)error;

我們看下該方法的實(shí)現(xiàn)

- (NSMutableURLRequest *)requestWithMethod:(NSString *)methodURLString:(NSString *)URLStringparameters:(id)parameterserror:(NSError *__autoreleasing *)error {NSParameterAssert(method);NSParameterAssert(URLString);// 初識(shí)化URLNSURL *url = [NSURL URLWithString:URLString];NSParameterAssert(url);// 初始化RequestNSMutableURLRequest *mutableRequest = [[NSMutableURLRequest alloc] initWithURL:url];// 設(shè)置請(qǐng)求方式mutableRequest.HTTPMethod = method;// 為某些屬性賦值【allowsCellularAccess,cachePolicy,HTTPShouldHandleCookies,HTTPShouldUsePipelining,networkServiceType,timeoutInterval】for (NSString *keyPath in AFHTTPRequestSerializerObservedKeyPaths()) {if ([self.mutableObservedChangedKeyPaths containsObject:keyPath]) {[mutableRequest setValue:[self valueForKeyPath:keyPath] forKey:keyPath];}}// 調(diào)用實(shí)現(xiàn)的協(xié)議mutableRequest = [[self requestBySerializingRequest:mutableRequest withParameters:parameters error:error] mutableCopy];return mutableRequest; }

在實(shí)現(xiàn)的協(xié)議中，真正的完成了一條完整的請(qǐng)求，請(qǐng)求地址，請(qǐng)求頭，請(qǐng)求體

- (NSURLRequest *)requestBySerializingRequest:(NSURLRequest *)requestwithParameters:(id)parameterserror:(NSError *__autoreleasing *)error {NSParameterAssert(request);NSMutableURLRequest *mutableRequest = [request mutableCopy];[self.HTTPRequestHeaders enumerateKeysAndObjectsUsingBlock:^(id field, id value, BOOL * __unused stop) {if (![request valueForHTTPHeaderField:field]) {// 設(shè)置請(qǐng)求頭[mutableRequest setValue:value forHTTPHeaderField:field];}}];// 序列化參數(shù) 用&拼接NSString *query = nil;if (parameters) {if (self.queryStringSerialization) {NSError *serializationError;query = self.queryStringSerialization(request, parameters, &serializationError);if (serializationError) {if (error) {*error = serializationError;}return nil;}} else {switch (self.queryStringSerializationStyle) {case AFHTTPRequestQueryStringDefaultStyle:query = AFQueryStringFromParameters(parameters);break;}}}// 如果是GET,HEAD,DELETE 走這邊if ([self.HTTPMethodsEncodingParametersInURI containsObject:[[request HTTPMethod] uppercaseString]]) {// 將序列化的參數(shù)拼到后面if (query && query.length > 0) {mutableRequest.URL = [NSURL URLWithString:[[mutableRequest.URL absoluteString] stringByAppendingFormat:mutableRequest.URL.query ? @"&%@" : @"?%@", query]];}} else {// POST、PUT走這里// #2864: an empty string is a valid x-www-form-urlencoded payloadif (!query) {query = @"";}// 如果沒有設(shè)置Content-Type，此處默認(rèn)設(shè)置成application/x-www-form-urlencodedif (![mutableRequest valueForHTTPHeaderField:@"Content-Type"]) {[mutableRequest setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];}// 配置請(qǐng)求體[mutableRequest setHTTPBody:[query dataUsingEncoding:self.stringEncoding]];}return mutableRequest; }

上面這塊是NSMutableURLRequest的整個(gè)過程，下面看下NSURLSessionDataTask

- (NSURLSessionDataTask *)dataTaskWithRequest:(NSURLRequest *)requestuploadProgress:(nullable void (^)(NSProgress *uploadProgress)) uploadProgressBlockdownloadProgress:(nullable void (^)(NSProgress *downloadProgress)) downloadProgressBlockcompletionHandler:(nullable void (^)(NSURLResponse *response, id _Nullable responseObject, NSError * _Nullable error))completionHandler {NSURLSessionDataTask *dataTask = [self.session dataTaskWithRequest:request];[self addDelegateForDataTask:dataTask uploadProgress:uploadProgressBlock downloadProgress:downloadProgressBlock completionHandler:completionHandler];return dataTask; }

該方法中通過NSURLSession創(chuàng)建了一個(gè)NSURLSessionDataTask對(duì)象，并給dataTask添加代理

在session的初始化中添加了安全鎖，保證了線程的安全。

- (NSURLSession *)session {@synchronized (self) {if (!_session) {_session = [NSURLSession sessionWithConfiguration:self.sessionConfiguration delegate:self delegateQueue:self.operationQueue];}}return _session; } - (void)addDelegateForDataTask:(NSURLSessionDataTask *)dataTaskuploadProgress:(nullable void (^)(NSProgress *uploadProgress)) uploadProgressBlockdownloadProgress:(nullable void (^)(NSProgress *downloadProgress)) downloadProgressBlockcompletionHandler:(void (^)(NSURLResponse *response, id responseObject, NSError *error))completionHandler {AFURLSessionManagerTaskDelegate *delegate = [[AFURLSessionManagerTaskDelegate alloc] initWithTask:dataTask];delegate.manager = self;delegate.completionHandler = completionHandler;dataTask.taskDescription = self.taskDescriptionForSessionTasks;[self setDelegate:delegate forTask:dataTask];delegate.uploadProgressBlock = uploadProgressBlock;delegate.downloadProgressBlock = downloadProgressBlock; }

上面就是一條完整的調(diào)用流程，回到最初的地方[dataTask resume];開始網(wǎng)絡(luò)請(qǐng)求

AFN使用技巧

創(chuàng)建一個(gè)工具類，繼承自AFNetwork的請(qǐng)求管理者

工具類中提供一個(gè)單例方法和一個(gè)基本的請(qǐng)求路徑，提供對(duì)GET和POST的請(qǐng)求封裝

發(fā)送請(qǐng)求使用自己封裝的工具類

方便修改，如果修改了底層的依賴框架，只用修改工具類就可以了

相關(guān)面試問題：

AFURLSessionManager主要負(fù)責(zé)哪些功能？

創(chuàng)建和管理NSURLSession、NSURLSessionTask

實(shí)現(xiàn)NSURLSessionDelegate等協(xié)議的代理方法

引入AFSecurityPolicy保證請(qǐng)求的網(wǎng)絡(luò)安全（證書的校驗(yàn)。公鑰的驗(yàn)證等）

引入AFNetworkReachabilityManager監(jiān)聽網(wǎng)絡(luò)狀態(tài)

?

?

?

?

?

?

?

總結(jié)

以上是生活随笔為你收集整理的小白的AFNetWorking之路的全部?jī)?nèi)容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網(wǎng)站內(nèi)容還不錯(cuò)，歡迎將生活随笔推薦給好友。