ImageLoader在ViewPage中的使用

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

    <TextView
        android:layout_width="match_parent"
        android:layout_height="60dp"
        android:background="@android:color/holo_blue_light"
        android:gravity="center"
        android:text="ImagleLoager_Gridview"
        android:textColor="@android:color/white"
        android:textSize="25sp" />

    <android.support.v4.view.ViewPager
        android:id="@+id/viewPage"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        />

</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="60dp"
    android:layout_height="60dp"
    android:orientation="vertical">
    <ImageView
        android:src="@drawable/ic_launcher"
        android:id="@+id/image"
        android:layout_width="50dp"
        android:layout_height="50dp" />
    <ProgressBar
        android:id="@+id/loading"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@android:color/holo_blue_light" />


</LinearLayout>

package application.weiyuan.com.listviewimageloader;

/**
 * Created by Administrator on 2017/7/26.
 */
public class Contants {

    public  static  String[]  imageUrls = new String[] {"http://h.hiphotos.baidu.com/image/w%3D230/sign=6e399656d343ad4ba62e41c3b2035a89/a08b87d6277f9e2fb00276fb1d30e924b899f30a.jpg"
            ,"http://h.hiphotos.baidu.com/image/w%3D230/sign=2c133914cdfc1e17fdbf8b327a91f67c/a8ec8a13632762d098b92abda2ec08fa513dc629.jpg"
            ,"http://g.hiphotos.baidu.com/image/w%3D230/sign=776ceec6c1cec3fd8b3ea076e689d4b6/faedab64034f78f0394889f97b310a55b3191c7c.jpg"
            ,"http://a.hiphotos.baidu.com/image/w%3D230/sign=a97edd106259252da3171a07049a032c/7dd98d1001e9390151b8b23479ec54e736d19605.jpg"
            ,"http://c.hiphotos.baidu.com/image/w%3D230/sign=5889f92579f40ad115e4c0e0672d1151/1b4c510fd9f9d72a32abde00d62a2834359bbbe4.jpg"
            ,"http://imgt8.bdstatic.com/it/u=2,926638203&fm=25&gp=0.jpg"
            ,"http://imgt8.bdstatic.com/it/u=2,926635772&fm=25&gp=0.jpg"
            ,"http://imgt9.bdstatic.com/it/u=2,926635207&fm=25&gp=0.jpg"
            ,"http://imgt8.bdstatic.com/it/u=2,926635826&fm=25&gp=0.jpg"
            ,"http://imgt7.bdstatic.com/it/u=2,767513653&fm=25&gp=0.jpg"
            ,"http://imgt9.bdstatic.com/it/u=2,861946843&fm=25&gp=0.jpg"
            ,"http://imgt7.bdstatic.com/it/u=2,956835248&fm=25&gp=0.jpg"
            ,"http://f.hiphotos.baidu.com/image/w%3D230/sign=1d32d901b9a1cd1105b675238913c8b0/d01373f082025aaf41e143faf8edab64034f1a2b.jpg"
            ,"http://imgt6.bdstatic.com/it/u=2,926633844&fm=25&gp=0.jpg"
            ,"http://imgt6.bdstatic.com/it/u=2,975762047&fm=25&gp=0.jpg"
            ,"http://imgt7.bdstatic.com/it/u=2,851741187&fm=25&gp=0.jpg"
            ,"http://imgt9.bdstatic.com/it/u=2,851680066&fm=25&gp=0.jpg"
            ,"http://imgt6.bdstatic.com/it/u=2,851165675&fm=25&gp=0.jpg"
            ,"http://imgt8.bdstatic.com/it/u=2,771262254&fm=25&gp=0.jpg"
            ,"http://imgt8.bdstatic.com/it/u=2,829083522&fm=25&gp=0.jpg"};

}

package application.weiyuan.com.listviewimageloader;

import android.app.Activity;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.ViewParent;
import android.widget.GridView;
import android.widget.ListView;

public class MainActivity extends Activity {

    private ViewPager viewPage;
    private ViewPagerAdapter listViewAdapter;

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

    private void initView() {
        viewPage = (ViewPager) findViewById(R.id.viewPage);
    }

    private void initData() {
// 创建适配器
        listViewAdapter = new ViewPagerAdapter(MainActivity.this);
// 添加适配器到listview中
        viewPage.setAdapter(listViewAdapter);
    }

}

package application.weiyuan.com.listviewimageloader;

import android.app.Application;

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;

/**
 * Created by Administrator on 2017/7/26.
 */
public class MyApplication extends Application {

    @Override
    public void onCreate() {
        super.onCreate();
        // 初始化参数
        ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(this)
                .threadPriority(Thread.NORM_PRIORITY - 2)               // 线程优先级
                .denyCacheImageMultipleSizesInMemory()                  // 当同一个Uri获取不同大小的图片，缓存到内存时，只缓存一个。默认会缓存多个不同的大小的相同图片
                .discCacheFileNameGenerator(new Md5FileNameGenerator()) // 将保存的时候的URI名称用MD5
                .tasksProcessingOrder(QueueProcessingType.LIFO)         // 设置图片下载和显示的工作队列排序
                .writeDebugLogs()                                       // 打印debug log
                .build();
        ImageLoader.getInstance().init(config);

    }
}

package application.weiyuan.com.listviewimageloader;

import android.content.Context;
import android.graphics.Bitmap;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.ProgressBar;
import android.widget.Toast;

import com.nostra13.universalimageloader.core.DisplayImageOptions;
import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.assist.FailReason;
import com.nostra13.universalimageloader.core.assist.ImageScaleType;
import com.nostra13.universalimageloader.core.display.FadeInBitmapDisplayer;
import com.nostra13.universalimageloader.core.listener.SimpleImageLoadingListener;

/**
 * Created by Administrator on 2017/7/27.
 */
public class ViewPagerAdapter  extends PagerAdapter{

    private final DisplayImageOptions options;
    private final ImageLoader imageLoader;
    private final Context mContext;

    public ViewPagerAdapter(Context context){
        // 获取上下文
        mContext = context;

        // 获取ImageLoader实例
        imageLoader = ImageLoader.getInstance();

        // 配置图片加载参数
        options = new DisplayImageOptions.Builder()
                .showImageForEmptyUri(R.drawable.ic_launcher)  // 设置图片Uri为空或是错误的时候显示的图片
                .showImageOnFail(R.drawable.ic_launcher)       // 设置图片加载或解码过程中发生错误显示的图片
                .resetViewBeforeLoading(true)               // 设置图片在下载前是否重置，复位
                .cacheOnDisc(true)                          // 设置下载的图片是否缓存在SD卡中
                .imageScaleType(ImageScaleType.EXACTLY)     // 设置图片以如何的编码方式显示
                .bitmapConfig(Bitmap.Config.RGB_565)        // 设置图片的解码类型
                .displayer(new FadeInBitmapDisplayer(300))  // 设置图片渐变显示
                .build();

    }

    @Override
    public int getCount() {
        return Contants.imageUrls.length;
    }

    @Override
    public boolean isViewFromObject(View view, Object object) {
        return view.equals(object);
    }

    @Override
    public void destroyItem(ViewGroup container, int position, Object object) {
//        super.destroyItem(container, position, object);
        ((ViewPager) container).removeView((View) object);
    }

    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        View imageLayout = View.inflate(mContext, R.layout.listview_item, null);

        ImageView imageView = (ImageView) imageLayout.findViewById(R.id.image);
        final ProgressBar spinner = (ProgressBar) imageLayout.findViewById(R.id.loading);

        // 加载图片
        imageLoader.displayImage(Contants.imageUrls[position], imageView, options, new SimpleImageLoadingListener() {
            @Override
            public void onLoadingStarted(String imageUri, View view) {
                // 显示加载进度条
                spinner.setVisibility(View.VISIBLE);
            }

            @Override
            public void onLoadingFailed(String imageUri, View view, FailReason failReason) {
                String message = null;

                // 获取图片失败类型
                switch (failReason.getType()) {
                    case IO_ERROR:          // 文件I/O错误
                        message = "Input/Output error";
                        break;

                    case DECODING_ERROR:      // 解码错误
                        message = "Image can't be decoded";
                        break;

                    case NETWORK_DENIED:      // 网络延迟
                        message = "Downloads are denied";
                        break;

                    case OUT_OF_MEMORY:           // 内存不足
                        message = "Out Of Memory error";
                        break;

                    case UNKNOWN:           // 原因不明
                        message = "Unknown error";
                        break;
                }

                Toast.makeText(mContext, message, Toast.LENGTH_SHORT).show();

                // 隐藏加载进度条
                spinner.setVisibility(View.GONE);
            }

            @Override
            public void onLoadingComplete(String imageUri, View view, Bitmap loadedImage) {
                // 隐藏加载进度条
                spinner.setVisibility(View.GONE);             // 不显示圆形进度条
            }
        });

        ((ViewPager) container).addView(imageLayout, 0);      // 将图片增加到ViewPager

        return imageLayout;
    }

}

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="application.weiyuan.com.listviewimageloader">
    <uses-permission android:name="android.permission.INTERNET"></uses-permission>
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>

    <application
        android:name=".MyApplication"
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>