Android学习之长按事件

桌面设置授权操作：

<uses-permission android:name="android.permission.SET_WALLPAPER"/>

MyLongClickDemo.java:

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnLongClickListener;
import android.widget.ImageView;
import android.widget.TextView;

public class MyLongClickDemo extends Activity {
	private TextView info = null;
	private ImageView img = null;

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		super.setContentView(R.layout.main);
		this.img = (ImageView) super.findViewById(R.id.img);
		this.info = (TextView) super.findViewById(R.id.info);
		this.img.setOnLongClickListener(new OnLongClickListenerImpl());
	}

	private class OnLongClickListenerImpl implements OnLongClickListener {

		public boolean onLongClick(View v) {
			try {
				MyLongClickDemo.this.clearWallpaper(); // 清除已有的桌面
				MyLongClickDemo.this.setWallpaper(MyLongClickDemo.this.img
						.getResources().openRawResource(R.drawable.mldn_bg)); // 设置桌面
				MyLongClickDemo.this.info.setText("手机桌面背景已修改。");
			} catch (Exception e) {
				e.printStackTrace() ;
				MyLongClickDemo.this.info.setText("手机桌面背景设置失败。");
			}
			return false;
		}
	}
}

 main.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 
	xmlns:android="http://schemas.android.com/apk/res/android"
	android:orientation="vertical" 
	android:layout_width="fill_parent"
	android:layout_height="fill_parent">
	<TextView 
		android:id="@+id/info"
		android:layout_width="fill_parent"
		android:layout_height="wrap_content" 
		android:text="长按图片将设置为桌面背景" />
	<ImageView
		android:id="@+id/img"
		android:layout_width="fill_parent"
		android:layout_height="fill_parent"
		android:src="@drawable/mldn_bg"/> 
</LinearLayout>