https://github.com/loopj/android-smart-image-view (smart imageview开源图片框架)

1.将代码复制到项目中, 复制SmartImageView引用

<com.loopj.android.image.SmartImageView
        android:id="@+id/image"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

2.设置图片URL，及请求失败时显示的图片

 imageView = (SmartImageView) findViewById(R.id.image);
        imageView.setImageUrl("http://www.baidu.com", R.drawable.ic_launcher_background);