HOME键监听

    我们经常会使用onKeyDown(int keyCode, KeyEvent event)方法来监听返回键的事件，这次在开发中遇到需要监听HOME键的事件，却发现使用onKeyDown(int keyCode, KeyEvent event)方法不起效果，于是度娘后了解，对Home键的监听主要通过注册广播接收器实现（拦截让窗口关闭的系统动作,然后根据Intent里面的具体参数,分析当前到底是Home键, 应用切换键,还是其他功能按键），在此做记录。

一：首先要先写一个receiver继承BroadcastReceiver 

public class HomeWatcherReceiver extends BroadcastReceiver {
private static final String SYSTEM_DIALOG_REASON_KEY = "reason";
private static final String SYSTEM_DIALOG_REASON_RECENT_APPS = "recentapps";
private static final String SYSTEM_DIALOG_REASON_HOME_KEY = "homekey";
private static final String SYSTEM_DIALOG_REASON_LOCK = "lock";
private static final String SYSTEM_DIALOG_REASON_ASSIST = "assist";

@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (action.equals(Intent.ACTION_CLOSE_SYSTEM_DIALOGS)) {
// android.intent.action.CLOSE_SYSTEM_DIALOGS
String reason = intent.getStringExtra(SYSTEM_DIALOG_REASON_KEY);

if (SYSTEM_DIALOG_REASON_HOME_KEY.equals(reason)) {
/**短按Home键*/
} else if (SYSTEM_DIALOG_REASON_RECENT_APPS.equals(reason)) {
// 长按Home键 或者 activity切换键
} else if (SYSTEM_DIALOG_REASON_LOCK.equals(reason)) {
// 锁屏
} else if (SYSTEM_DIALOG_REASON_ASSIST.equals(reason)) {
// samsung 长按Home键
}
}
}
}二：然后是注册广播监听（注意需要使用动态注册，静态注册不起作用）
/**注册监听home键*/
mHomeKeyReceiver = new HomeWatcherReceiver();
IntentFilter homeFilter = new IntentFilter(Intent.ACTION_CLOSE_SYSTEM_DIALOGS);
registerReceiver(mHomeKeyReceiver, homeFilter);

/**解注册home键的监听*/
if (null != mHomeKeyReceiver) {
unregisterReceiver(mHomeKeyReceiver);
}

三：剩下的就是在适当的地方调用即可。