android中设置桌面壁纸

package com.example.androidapi.app;import java.io.IOException;import android.app.Activity;import android.app.WallpaperManager;import android.graphics.Color;import android.graphics.PorterDuff;import android.graphics.drawable.Drawable;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.ImageView;import com.example.androidapi.R;public class SetWallpaperActivity extends Activity {    final static private int[] mColors =            {Color.BLUE, Color.GREEN, Color.RED, Color.LTGRAY,      Color.MAGENTA, Color.CYAN,Color.YELLOW, Color.WHITE};    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.wallpaper_2);                final WallpaperManager wallpaperManager = WallpaperManager.getInstance(this);        //获取系统桌面壁纸        final Drawable wallpaperDrawable = wallpaperManager.getDrawable();        final ImageView imageView = (ImageView) findViewById(R.id.imageview);        imageView.setDrawingCacheEnabled(true);        imageView.setImageDrawable(wallpaperDrawable);        Button randomize = (Button) findViewById(R.id.randomize);        randomize.setOnClickListener(new OnClickListener() {            public void onClick(View view) {                int mColor = (int) Math.floor(Math.random() * mColors.length);                wallpaperDrawable.setColorFilter(mColors[mColor], PorterDuff.Mode.MULTIPLY);                //设置颜色                imageView.setImageDrawable(wallpaperDrawable);                imageView.invalidate();            }        });        Button setWallpaper = (Button) findViewById(R.id.setwallpaper);        setWallpaper.setOnClickListener(new OnClickListener() {            public void onClick(View view) {                try {                //将重新设置的颜色设置为桌面壁纸                    wallpaperManager.setBitmap(imageView.getDrawingCache());                    finish();                } catch (IOException e) {                    e.printStackTrace();                }            }        });    }}