2019獨角獸企業(yè)重金招聘Python工程師標(biāo)準(zhǔn)>>>

直奔主題：

1、主要原理就是利用定時任務(wù)器定時切換ViewPager的頁面。 2、里面用了一個讀取網(wǎng)絡(luò)圖片的插件，做客戶端使用本地圖片輪播的也很少。

先上個效果圖：

項目代碼結(jié)構(gòu)截圖：

自定義View 的布局文件layout_slideshow.xml： [html] view plain copy 在CODE上查看代碼片派生到我的代碼片

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent">

<android.support.v4.view.ViewPager android:id="@+id/viewPager" android:layout_width="match_parent" android:layout_height="match_parent" /> <LinearLayout android:id="@+id/dotLayout" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_alignParentBottom="true" android:padding="8dp" android:gravity="right" android:orientation="horizontal"> <View android:id="@+id/v_dot1" android:layout_width="8dp" android:layout_height="8dp" android:background="@drawable/dot_focus" /> <View android:id="@+id/v_dot2" android:layout_width="8dp" android:layout_height="8dp" android:layout_marginLeft="5dp" android:background="@drawable/dot_blur" /> </LinearLayout>

</RelativeLayout>

主界面布局文件activity_main.xml： [html] view plain copy 在CODE上查看代碼片派生到我的代碼片 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:background="#FFFFFF" tools:context="com.example.slideshowdemo.MainActivity" >

<!-- 主題圖片 --> <com.example.slideshowdemo.customview.SlideShowView android:id="@+id/slideshowView" android:layout_width="fill_parent" android:layout_height="180dp" android:layout_centerHorizontal="true" />

</LinearLayout>

自定義View 代碼： [java] view plain copy 在CODE上查看代碼片派生到我的代碼片 package com.example.slideshowdemo.customview;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

import android.content.Context;
import android.graphics.drawable.Drawable;
import android.os.AsyncTask;
import android.os.Handler;
import android.os.Message;
import android.os.Parcelable;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.FrameLayout;
import android.widget.ImageView;
import android.widget.ImageView.ScaleType;
import android.widget.LinearLayout;

import com.example.slideshowdemo.R;
import com.nostra13.universalimageloader.cache.disc.naming.Md5FileNameGenerator;
import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;
import com.nostra13.universalimageloader.core.assist.QueueProcessingType;

/**

• ViewPager實現(xiàn)的輪播圖廣告自定義視圖，如京東首頁的廣告輪播圖效果；
• 既支持自動輪播頁面也支持手勢滑動切換頁面

*/

public class SlideShowView extends FrameLayout {

// 使用universal-image-loader插件讀取網(wǎng)絡(luò)圖片，需要工程導(dǎo)入universal-image-loader-1.8.6-with-sources.jar private ImageLoader imageLoader = ImageLoader.getInstance(); //輪播圖圖片數(shù)量 private final static int IMAGE_COUNT = 5; //自動輪播的時間間隔 private final static int TIME_INTERVAL = 5; //自動輪播啟用開關(guān) private final static boolean isAutoPlay = true; //自定義輪播圖的資源 private String[] imageUrls; //放輪播圖片的ImageView 的list private List<ImageView> imageViewsList; //放圓點的View的list private List<View> dotViewsList; private ViewPager viewPager; //當(dāng)前輪播頁 private int currentItem = 0; //定時任務(wù) private ScheduledExecutorService scheduledExecutorService; private Context context; //Handler private Handler handler = new Handler(){ @Override public void handleMessage(Message msg) { // TODO Auto-generated method stub super.handleMessage(msg); viewPager.setCurrentItem(currentItem); } }; public SlideShowView(Context context) { this(context,null); // TODO Auto-generated constructor stub } public SlideShowView(Context context, AttributeSet attrs) { this(context, attrs, 0); // TODO Auto-generated constructor stub } public SlideShowView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); this.context = context; initImageLoader(context); initData(); if(isAutoPlay){ startPlay(); } } /** * 開始輪播圖切換 */ private void startPlay(){ scheduledExecutorService = Executors.newSingleThreadScheduledExecutor(); scheduledExecutorService.scheduleAtFixedRate(new SlideShowTask(), 1, 4, TimeUnit.SECONDS); } /** * 停止輪播圖切換 */ private void stopPlay(){ scheduledExecutorService.shutdown(); } /** * 初始化相關(guān)Data */ private void initData(){ imageViewsList = new ArrayList<ImageView>(); dotViewsList = new ArrayList<View>(); // 一步任務(wù)獲取圖片 new GetListTask().execute(""); } /** * 初始化Views等UI */ private void initUI(Context context){ if(imageUrls == null || imageUrls.length == 0) return; LayoutInflater.from(context).inflate(R.layout.layout_slideshow, this, true); LinearLayout dotLayout = (LinearLayout)findViewById(R.id.dotLayout); dotLayout.removeAllViews(); // 熱點個數(shù)與圖片特殊相等 for (int i = 0; i < imageUrls.length; i++) { ImageView view = new ImageView(context); view.setTag(imageUrls[i]); if(i==0)//給一個默認(rèn)圖 view.setBackgroundResource(R.drawable.appmain_subject_1); view.setScaleType(ScaleType.FIT_XY); imageViewsList.add(view); ImageView dotView = new ImageView(context); LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT); params.leftMargin = 4; params.rightMargin = 4; dotLayout.addView(dotView, params); dotViewsList.add(dotView); } viewPager = (ViewPager) findViewById(R.id.viewPager); viewPager.setFocusable(true); viewPager.setAdapter(new MyPagerAdapter()); viewPager.setOnPageChangeListener(new MyPageChangeListener()); } /** * 填充ViewPager的頁面適配器 * */ private class MyPagerAdapter extends PagerAdapter{ @Override public void destroyItem(View container, int position, Object object) { // TODO Auto-generated method stub //((ViewPag.er)container).removeView((View)object); ((ViewPager)container).removeView(imageViewsList.get(position)); } @Override public Object instantiateItem(View container, int position) { ImageView imageView = imageViewsList.get(position); imageLoader.displayImage(imageView.getTag() + "", imageView); ((ViewPager)container).addView(imageViewsList.get(position)); return imageViewsList.get(position); } @Override public int getCount() { // TODO Auto-generated method stub return imageViewsList.size(); } @Override public boolean isViewFromObject(View arg0, Object arg1) { // TODO Auto-generated method stub return arg0 == arg1; } @Override public void restoreState(Parcelable arg0, ClassLoader arg1) { // TODO Auto-generated method stub } @Override public Parcelable saveState() { // TODO Auto-generated method stub return null; } @Override public void startUpdate(View arg0) { // TODO Auto-generated method stub } @Override public void finishUpdate(View arg0) { // TODO Auto-generated method stub } } /** * ViewPager的監(jiān)聽器 * 當(dāng)ViewPager中頁面的狀態(tài)發(fā)生改變時調(diào)用 * */ private class MyPageChangeListener implements OnPageChangeListener{ boolean isAutoPlay = false; @Override public void onPageScrollStateChanged(int arg0) { // TODO Auto-generated method stub switch (arg0) { case 1:// 手勢滑動，空閑中 isAutoPlay = false; break; case 2:// 界面切換中 isAutoPlay = true; break; case 0:// 滑動結(jié)束，即切換完畢或者加載完畢 // 當(dāng)前為最后一張，此時從右向左滑，則切換到第一張 if (viewPager.getCurrentItem() == viewPager.getAdapter().getCount() - 1 && !isAutoPlay) { viewPager.setCurrentItem(0); } // 當(dāng)前為第一張，此時從左向右滑，則切換到最后一張 else if (viewPager.getCurrentItem() == 0 && !isAutoPlay) { viewPager.setCurrentItem(viewPager.getAdapter().getCount() - 1); } break; } } @Override public void onPageScrolled(int arg0, float arg1, int arg2) { // TODO Auto-generated method stub } @Override public void onPageSelected(int pos) { // TODO Auto-generated method stub currentItem = pos; for(int i=0;i < dotViewsList.size();i++){ if(i == pos){ ((View)dotViewsList.get(pos)).setBackgroundResource(R.drawable.dot_focus); }else { ((View)dotViewsList.get(i)).setBackgroundResource(R.drawable.dot_blur); } } } } /** *執(zhí)行輪播圖切換任務(wù) * */ private class SlideShowTask implements Runnable{ @Override public void run() { // TODO Auto-generated method stub synchronized (viewPager) { currentItem = (currentItem+1)%imageViewsList.size(); handler.obtainMessage().sendToTarget(); } } } /** * 銷毀ImageView資源，回收內(nèi)存 * */ private void destoryBitmaps() { for (int i = 0; i < IMAGE_COUNT; i++) { ImageView imageView = imageViewsList.get(i); Drawable drawable = imageView.getDrawable(); if (drawable != null) { //解除drawable對view的引用 drawable.setCallback(null); } } } /** * 異步任務(wù),獲取數(shù)據(jù) * */ class GetListTask extends AsyncTask<String, Integer, Boolean> { @Override protected Boolean doInBackground(String... params) { try { // 這里一般調(diào)用服務(wù)端接口獲取一組輪播圖片，下面是從百度找的幾個圖片 imageUrls = new String[]{ "http://image.zcool.com.cn/56/35/1303967876491.jpg", "http://image.zcool.com.cn/59/54/m_1303967870670.jpg", "http://image.zcool.com.cn/47/19/1280115949992.jpg", "http://image.zcool.com.cn/59/11/m_1303967844788.jpg" }; return true; } catch (Exception e) { e.printStackTrace(); return false; } } @Override protected void onPostExecute(Boolean result) { super.onPostExecute(result); if (result) { initUI(context); } } } /** * ImageLoader 圖片組件初始化 * * @param context */ public static void initImageLoader(Context context) { // This configuration tuning is custom. You can tune every option, you // may tune some of them, // or you can create default configuration by // ImageLoaderConfiguration.createDefault(this); // method. ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(context).threadPriority(Thread.NORM_PRIORITY - 2).denyCacheImageMultipleSizesInMemory().discCacheFileNameGenerator(new Md5FileNameGenerator()).tasksProcessingOrder(QueueProcessingType.LIFO).writeDebugLogs() // Remove // for // release // app .build(); // Initialize ImageLoader with configuration. ImageLoader.getInstance().init(config); }

}

主界面Activity代碼： [java] view plain copy 在CODE上查看代碼片派生到我的代碼片 package com.example.slideshowdemo;

import android.app.Activity;
import android.os.Bundle;

public class MainActivity extends Activity {

@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); }

}

下面附上使用到的圖片素材： 熱點圖1： 熱點圖2： 效果默認(rèn)圖片：（建議做一個灰色的不含有具體內(nèi)容的默認(rèn)加載圖片，這里做demo就隨便找了一個）

完整工程代碼下載地址：http://download.csdn.net/detail/catoop/8025409

轉(zhuǎn)載于:https://my.oschina.net/u/1177694/blog/709765

總結(jié)

以上是生活随笔為你收集整理的安卓首页图片轮播效果(淘宝、京东首页广告效果)的全部內(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，歡迎將生活随笔推薦給好友。