按住2秒后才有所操作
在main.xml中的代码如下：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<TextView
android:id="@+id/info"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="长按图片，将图片为背景"/>
<ImageView
android:id="@+id/img"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:src="@drawable/mldn_bg"/>
</LinearLayout>
在MyLongClickDemo.java中的代码如下：
package com.tarena.longclick;
import java.io.IOException;
import android.app.Activity;
import android.content.res.Resources.NotFoundException;
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.info = (TextView) super.findViewById(R.id.info);
this.img = (ImageView) super.findViewById(R.id.img);
this.img.setOnLongClickListener(new OnLongClickListenerImpl());
}
private class OnLongClickListenerImpl implements OnLongClickListener{
public boolean onLongClick(View v) {
try { //生成try catch，先选中要try catch的部分，再右键Surround With --> Try/catch Block
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) {
MyLongClickDemo.this.info.setText("手机桌面背景设置失败");
}
return false;
}
}
}
然后还要在AndroidManifest.xml中修改权限：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.tarena.longclick"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="10" />
<application
android:icon="@drawable/ic_launcher"
android:label="@string/app_name" >
<activity
android:name=".MyLongClickDemo"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
<uses-permission android:name="android.permission.SET_WALLPAPER"/> //授权
</manifest>