Android怎么从设置相册中的照片作背景（刚做的例子）

 

package com.fit.background;

import java.io.IOException;

import android.app.Activity;
import android.app.WallpaperManager;
import android.content.Intent;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends Activity {
    /** Called when the activity is first created. */
 String path;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
       
        Button choose=(Button) findViewById(R.id.choose);
        choose.setOnClickListener(new OnClickListener() {
   
   @Override
   public void onClick(View v) {
     Intent i=new Intent();
     i.setType("image/*");
     i.setAction(Intent.ACTION_GET_CONTENT);
     Intent intent=Intent.createChooser(i, "Select Picture");
     startActivityForResult(intent, 2);
   }
  });
//         Bitmap bit=BitmapFactory.decodeFile(Environment.getExternalStorageDirectory()+"/xiaoxiong.jpg");
    }
   
   
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
     switch(requestCode){
     case 2:
      Uri imageUri = null;
      if(data!=null){
      imageUri=data.getData();
     
      
      String imagePath="";
      String[] projection={MediaStore.Images.Media.DATA};
      Cursor cursor=managedQuery(imageUri, projection, null, null, null);
      if(cursor!=null){
       int colomn_index=cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
       cursor.moveToFirst();
       imagePath=cursor.getString(colomn_index);
      }
       Bitmap bit=BitmapFactory.decodeFile(imagePath); 
             try {
               WallpaperManager manager=WallpaperManager.getInstance(this);
         manager.setBitmap(bit);
        } catch (IOException e) {
         e.printStackTrace();
        }
        
      }
      Toast.makeText(MainActivity.this, path, Toast.LENGTH_LONG).show();
      break;
     }
    }
}