桌面设置，以及获取左面图片

/*
 * Copyright (C) 2009 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.example.android.apis.app;
// Need the following import to get access to the app resources, since this
// class is in a sub-package.
import com.example.android.apis.R;
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.WindowManager;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
/**
 * <h3>SetWallpaper Activity</h3>
 *
 * <p>This demonstrates the how to write an activity that gets the current system wallpaper,
 * modifies it and sets the modified bitmap as system wallpaper.</p>
 */
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};
    /**
     * Initialization of the Activity after it is first created.  Must at least
     * call {@link android.app.Activity#setContentView setContentView()} to
     * describe what is to be displayed in the screen.
     */
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // Be sure to call the super class.
        super.onCreate(savedInstanceState);
        // See res/layout/wallpaper_2.xml for this
        // view layout definition, which is being set here as
        // the content of our screen.
        setContentView(R.layout.wallpaper_2);
        final WallpaperManager wallpaperManager = WallpaperManager.getInstance(this); // Singleton instance. Wall manager.
        final Drawable wallpaperDrawable = wallpaperManager.getDrawable(); //get wall drawable.
        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);
                imageView.setImageDrawable(wallpaperDrawable);
                imageView.invalidate();
            }
        });
        Button setWallpaper = (Button) findViewById(R.id.setwallpaper);
        setWallpaper.setOnClickListener(new OnClickListener() {
            public void onClick(View view) {
                try {
                    wallpaperManager.setBitmap(imageView.getDrawingCache()); //set wall as drawable.
                    finish();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        });
    }
}