package com.android.test; import java.io.File; import java.io.IOException; import android.app.Activity; import android.app.WallpaperManager; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.os.Bundle; import android.os.Environment; import android.widget.Toast; public class WallPaperActivity extends Activity {     public static final String FILE_NAME = "MM-320x480.png";     @Override     protected void onCreate (Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         Bitmap wall = getWallPaper();         setWallPaper(wall);     }     //从sdcard中获取图片     private Bitmap getWallPaper() {         //拿到sdcard的根目录的路径         File root = Environment.getExternalStorageDirectory();         //拿到sdcard中指定的图片         File wall = new File(root, FILE_NAME);         //拿到图片的绝对路径         String path = wall.getAbsolutePath();         System.out.println("path = " + path);         //根据图片的绝对路径获取图片         return BitmapFactory.decodeFile(path);     }     //将获取的图片设置为墙纸     private void setWallPaper(Bitmap wall) {         //获取一个墙纸管理器的对象         WallpaperManager wManager = WallpaperManager.getInstance(this);         try {             //将对应的图片设置为墙纸             wManager.setBitmap(wall);         }         catch (IOException e) {             String msg = "设置桌面背景异常：" + e.getLocalizedMessage();             System.out.println("设置桌面背景异常：" + msg);             Toast.makeText(this, msg, Toast.LENGTH_LONG).show();             e.printStackTrace();         }     } }