Android通过Intent.ACTION_CLOSE_SYSTEM_DIALOGS监听Home按键消息

Android对屏幕下方常用的四个按键消息处理是不一致的：

1、搜索按键的消息在onKeyDown或者onKeyUp中接收；

2、菜单按键的消息在onCreateOptionsMenu、onKeyDown或onKeyUp方法中接收；

3、返回按键的消息可以在onBackPressed、onKeyDown或onKeyUp方法中接收。

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
switch( keyCode ){
case KeyEvent.KEYCODE_BACK:{

}
break;
case KeyEvent.KEYCODE_MENU:{

}
break;
case KeyEvent.KEYCODE_SEARCH:{

}
break;
default:{

}
break;
}
return super.onKeyDown(keyCode, event);
}

@Override
public boolean onKeyUp(int keyCode, KeyEvent event) {
switch( keyCode ){
case KeyEvent.KEYCODE_BACK:{

}
break;
case KeyEvent.KEYCODE_MENU:{

}
break;
case KeyEvent.KEYCODE_SEARCH:{

}
break;
default:{

}
break;
}
return super.onKeyUp(keyCode, event);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
return true;
}

@Override
public void onBackPressed() {
super.onBackPressed();
}

对于Home按键消息的处理，既不能通过onKeyDown、onKeyUp接收到，android也没有提供专有的方法接收按键消息，个人估计home按键算是一个app异常信息处理的后门，比如ANR后，按其它按钮没有比按Home按键好使，所以android为了能够提供更好的用户体验，没有提供供用户监听home按键消息的方法。

注： 网上提供了各种各样监听Home按键消息的方法，但只有这个比较好使。

但办法总是有的，在每次点击Home按键时都会发出一个action为Intent.ACTION_CLOSE_SYSTEM_DIALOGS的广播，它是关闭系统Dialog的广播，我们可以通过注册它来监听Home按键消息，我自定义了一个home按键监听工具类，代码如下，使用说明参见类名上方的使用说明：

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;

/**
* Home按键监听类
* 使用说明：
* 1、初始化HomeListen
* HomeListen homeListen = new HomeListen( this );
* homeListen.setOnHomeBtnPressListener( new setOnHomeBtnPressListener(){
* 		@Override
* 		public void onHomeBtnPress( ){
* 			// 按下Home按键回调
* 		}
*
* 		@Override
* 		public void onHomeBtnLongPress( ){
* 			// 长按Home按键回调
* 		}
* });
*
* 2、在onResume方法中启动HomeListen广播：
* homeListen.start();
*
* 3、在onPause方法中停止HomeListen广播：
* homeListen.stop( );
* */
public class HomeListen {
public HomeListen(Context context) {
mContext = context;
mHomeBtnReceiver = new HomeBtnReceiver( );
mHomeBtnIntentFilter = new IntentFilter(Intent.ACTION_CLOSE_SYSTEM_DIALOGS);
}

public void setOnHomeBtnPressListener( OnHomeBtnPressLitener onHomeBtnPressListener ){
mOnHomeBtnPressListener = onHomeBtnPressListener;
}

public void start( ){
mContext.registerReceiver( mHomeBtnReceiver, mHomeBtnIntentFilter );
}

public void stop( ){
mContext.unregisterReceiver( mHomeBtnReceiver );
}

class HomeBtnReceiver extends BroadcastReceiver{
@Override
public void onReceive(Context context, Intent intent) {
receive( context, intent );
}
}

private void receive(Context context, Intent intent){
String action = intent.getAction();
if (action.equals(Intent.ACTION_CLOSE_SYSTEM_DIALOGS)) {
String reason = intent.getStringExtra( "reason" );
if (reason != null) {
if( null != mOnHomeBtnPressListener ){
if( reason.equals( "homekey" ) ){
// 按Home按键
mOnHomeBtnPressListener.onHomeBtnPress( );
}else if( reason.equals( "recentapps" ) ){
// 长按Home按键
mOnHomeBtnPressListener.onHomeBtnLongPress( );
}
}
}
}
}

public interface OnHomeBtnPressLitener{
public void onHomeBtnPress( );
public void onHomeBtnLongPress( );
}

private Context mContext = null;
private IntentFilter mHomeBtnIntentFilter = null;
private OnHomeBtnPressLitener mOnHomeBtnPressListener = null;
private HomeBtnReceiver mHomeBtnReceiver = null;
}

在Activity中做如下调用即可：

public class HomeListenActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home_listen_layout);
initHomeListen( );
}

@Override
protected void onResume( ) {
super.onResume();
mHomeListen.start( );
}

@Override
protected void onPause() {
super.onPause();
mHomeListen.stop( );
}

private void initHomeListen( ){
mHomeListen = new HomeListen( this );
mHomeListen.setOnHomeBtnPressListener( new OnHomeBtnPressLitener( ) {
@Override
public void onHomeBtnPress() {
showToast( "按下Home按键！" );
}

@Override
public void onHomeBtnLongPress() {
showToast( "长按Home按键！" );
}
});
}

private void showToast( String toastInfoStr ){
Toast.makeText( this, toastInfoStr, Toast.LENGTH_LONG ).show( );
}

private HomeListen mHomeListen = null;
}