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, 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;
    }

}