简单使用ImageLoader

首先本工程要加一个依赖包 Universal-Image-Loader

1：创建MyApplication类继承Application  重写oncreate方法

public class MyApplication extends Application {

@Override
public void onCreate() {
super.onCreate();
//        默认的ImageLoaderconfiguration  这只会加载图片  而不会又缓存等
ImageLoaderConfiguration configuration = ImageLoaderConfiguration.createDefault(this);
ImageLoader.getInstance().init(configuration);
//
//        自定义的ImageLoaderConfiguration
File file = StorageUtils.getIndividualCacheDirectory(this, Environment.getDownloadCacheDirectory().getPath());
ImageLoaderConfiguration configuration = new ImageLoaderConfiguration.Builder(this)
.threadPoolSize(3)
.memoryCache(new LruMemoryCache(2 * 1024 * 1024))//内存缓存图片 2M
.diskCache(new UnlimitedDiskCache(file))//配饰sdcard缓存路径
.diskCacheSize(50 * 1024 * 1024)// sdcard上缓存50M的图片
.diskCacheFileCount(100)//缓存文件的数量   100个
.diskCacheFileNameGenerator(new Md5FileNameGenerator())
.build();
ImageLoader.getInstance().init(configuration);
}
}

2：在清单文件注册  在Application里加一个name属性 名字是自定义的Application

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.bawey.qizepu20170425">

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>

<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:name=".MyApplication"
android:roundIcon="@mipmap/ic_launcher_round"
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>

3：调用时：在适配器类加载图片，下面是getView方法

public View getView(int position, View convertView, ViewGroup parent) {
if (convertView==null){
convertView=View.inflate(context, R.layout.listview_item,null);
}
ImageView image_1 = (ImageView) convertView.findViewById(R.id.image_1);
//        使用默认的ImageLoaderConfiguration
//        ImageLoader.getInstance().displayImage(list.get(position).getAlbums().get(0),image_1);
//        使用自定义的ImageLoaderConfiguration
ImageLoader.getInstance().displayImage(list.get(position).getAlbums().get(0),image_1,options);

return convertView;
}

4：注意：如果用自定义的ImageLoaderConfiguration需要在适配器的构造方法中设置支持缓存

private DisplayImageOptions options;

public MyListViewAdapter(Context context, List<Foods.ResultBean.DataBean> list) {

this.context=context;
this.list=list;

options=new DisplayImageOptions.Builder()
.cacheInMemory(true)//是否内存缓存
.cacheOnDisk(true)//是否sdcard缓存
.build();//构建图片缓存的选项
}

适配器详细代码如下

public class MyListViewAdapter extends BaseAdapter {
private Context context;
private List<Foods.ResultBean.DataBean> list;
private DisplayImageOptions options;

public MyListViewAdapter(Context context,
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List<Foods.ResultBean.DataBean> list) {

this.context=context;
this.list=list;

options=new DisplayImageOptions.Builder()
.cacheInMemory(true)//是否内存缓存
.cacheOnDisk(true)//是否sdcard缓存
.build();//构建图片缓存的选项
}

@Override
public int getCount() {
return list.size();
}

@Override
public Object getItem(int position) {
return null;
}

@Override
public long getItemId(int position) {
return 0;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
if (convertView==null){
convertView=View.inflate(context, R.layout.listview_item,null);
}
ImageView image_1 = (ImageView) convertView.findViewById(R.id.image_1);
TextView text_1 = (TextView) convertView.findViewById(R.id.text_1);
text_1.setText(list.get(position).getTitle());
//        使用默认的ImageLoaderConfiguration
//        ImageLoader.getInstance().displayImage(list.get(position).getAlbums().get(0),image_1);
//        使用自定义的ImageLoaderConfiguration
ImageLoader.getInstance().displayImage(list.get(position).getAlbums().get(0),image_1,options);

return convertView;
}

}