Android Home键监听

Android 普通键值可以直接在dispatchKeyEvent（）中处理，但Home键，比较特殊，需要单独监听其广播，且必须为动态广播，其静态广播无效；

需求：Home键，设置 Kill 自己，但设置中有多个Activity，在每个Activiy 中年监听Home键广播不现实，必须把监听广播抽取出来在同一个类中实现，考虑到BaseActivity；

public class BaseActivity extends Activity {
    
    private HomeWatcherReceiver mHomeWatcherReceiver = null;
    private boolean isNeedFinish = false;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        registerReceiver();
    }
    
    public void setBackFinish(boolean flag) {
        isNeedFinish = flag;
    }
    
    private void registerReceiver() {
        mHomeWatcherReceiver = new HomeWatcherReceiver();
        IntentFilter filter = new IntentFilter(Intent.ACTION_CLOSE_SYSTEM_DIALOGS);
        registerReceiver(mHomeWatcherReceiver, filter);
    }
    
    
    @Override
    public boolean dispatchKeyEvent(KeyEvent event) {
        
        int KeyCode = event.getKeyCode();
        
        if (event.getAction() == KeyEvent.ACTION_DOWN) {
            if (event.getKeyCode() == KeyEvent.KEYCODE_BACK) {
                this.finish();
                System.gc();
                return true;
            }
        }
        return super.dispatchKeyEvent(event);
    }
    public class HomeWatcherReceiver extends BroadcastReceiver {

        private static final String SYSTEM_DIALOG_REASON_KEY = "reason";
        private static final String SYSTEM_DIALOG_REASON_HOME_KEY = "homekey";
        
        @Override
        public void onReceive(Context context, Intent intent) {

            String intentAction = intent.getAction();
            Log.i(MyAPP, "intentAction =" + intentAction);
            if (TextUtils.equals(intentAction, Intent.ACTION_CLOSE_SYSTEM_DIALOGS)) {
                String reason = intent.getStringExtra(SYSTEM_DIALOG_REASON_KEY);
                Log.i(MyAPP, "reason =" + reason);
                if (TextUtils.equals(SYSTEM_DIALOG_REASON_HOME_KEY, reason)) {
                    BaseActivity.this.finish();
                }
            }
        }

    }
    
    @Override
    protected void onDestroy() {
        super.onDestroy();
        
        if (mHomeWatcherReceiver != null) {
            try {
                unregisterReceiver(mHomeWatcherReceiver);
            }
            catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
}