Android Home鍵監聽

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 Android Back Home鍵監聽

 

Back鍵的監聽

　　對於Back鍵的監聽比較容易,可以在多個系統回調處攔截,比如在activity的下列方法中都可以收到Back鍵按下的事件:

    @Override    public void onBackPressed() {        // super.onBackPressed();//注釋掉這行,back鍵不退出activity        Log.i(LOG_TAG, "onBackPressed");    }    @Override    public boolean dispatchKeyEvent(KeyEvent event) {        Log.i(LOG_TAG, "dispatchKeyEvent: keyCode -- " + event.getKeyCode());        return super.dispatchKeyEvent(event);    }    @Override    public boolean onKeyDown(int keyCode, KeyEvent event) {        Log.i(LOG_TAG, "onKeyDown: keyCode -- " + keyCode);        switch (keyCode) {        case KeyEvent.KEYCODE_BACK:            Log.i(LOG_TAG, "KeyEvent.KEYCODE_BACK");            break;        case KeyEvent.KEYCODE_MENU:            Log.i(LOG_TAG, "KeyEvent.KEYCODE_MENU");            break;        case KeyEvent.KEYCODE_HOME:            Log.i(LOG_TAG, "KeyEvent.KEYCODE_HOME");            // 收不到            break;        case KeyEvent.KEYCODE_APP_SWITCH:            Log.i(LOG_TAG, "KeyEvent.KEYCODE_APP_SWITCH");            // 收不到            break;        default:            break;        }        return super.onKeyDown(keyCode, event);    }

 

Home鍵的廣播監聽

　　對於Home鍵的監聽不是那麼容易,因為Home鍵可以將程式退出放在後台,所以這個事件是直接分發給系統,系統接收到之後做相應處理,Home鍵的事件不是直接傳遞到應用裡面.所以在上述監聽Back鍵的代碼中,相應的回調中是收不到Home鍵的事件的.

　　參考文後的部落格連結,對Home鍵的監聽主要通過註冊廣播接收器實現,攔截讓視窗關閉的系統動作,然後根據Intent裡面的具體參數,分析當前到底是Home鍵, 應用程式切換鍵,還是其他功能按鍵.

　　接收器實現如下:

package com.mengdd.hellohome;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.util.Log;public class HomeWatcherReceiver extends BroadcastReceiver {    private static final String LOG_TAG = "HomeReceiver";    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();        Log.i(LOG_TAG, "onReceive: action: " + action);        if (action.equals(Intent.ACTION_CLOSE_SYSTEM_DIALOGS)) {            // android.intent.action.CLOSE_SYSTEM_DIALOGS            String reason = intent.getStringExtra(SYSTEM_DIALOG_REASON_KEY);            Log.i(LOG_TAG, "reason: " + reason);            if (SYSTEM_DIALOG_REASON_HOME_KEY.equals(reason)) {                // 短按Home鍵                Log.i(LOG_TAG, "homekey");            }            else if (SYSTEM_DIALOG_REASON_RECENT_APPS.equals(reason)) {                // 長按Home鍵 或者 activity切換鍵                Log.i(LOG_TAG, "long press home key or activity switch");            }            else if (SYSTEM_DIALOG_REASON_LOCK.equals(reason)) {                // 鎖屏                Log.i(LOG_TAG, "lock");            }            else if (SYSTEM_DIALOG_REASON_ASSIST.equals(reason)) {                // samsung 長按Home鍵                Log.i(LOG_TAG, "assist");            }        }    }}

　　注意不同手機的按鍵不同,所以需要對不同理由做區分.

 

Home鍵監聽廣播註冊

　　廣播接收器的註冊有兩種方式,一種是靜態註冊,即寫在manifest裡面聲明;另一種是動態註冊,即在Java代碼裡面註冊.

　　上面對Home鍵實現監聽的這個receiver,靜態註冊如下:

        <receiver android:name="com.mengdd.hellohome.HomeWatcherReceiver" >            <intent-filter>                <action android:name="android.intent.action.CLOSE_SYSTEM_DIALOGS" />            </intent-filter>        </receiver>

　　但是發現靜態註冊不起作用,即收不到onReceive回調.

 

　　採用動態註冊:

    private static HomeWatcherReceiver mHomeKeyReceiver = null;    private static void registerHomeKeyReceiver(Context context) {        Log.i(LOG_TAG, "registerHomeKeyReceiver");        mHomeKeyReceiver = new HomeWatcherReceiver();        final IntentFilter homeFilter = new IntentFilter(Intent.ACTION_CLOSE_SYSTEM_DIALOGS);        context.registerReceiver(mHomeKeyReceiver, homeFilter);    }    private static void unregisterHomeKeyReceiver(Context context) {        Log.i(LOG_TAG, "unregisterHomeKeyReceiver");        if (null != mHomeKeyReceiver) {            context.unregisterReceiver(mHomeKeyReceiver);        }    }

　　

　　在Activity的onResume和onPause裡面分別調用:

    @Override    protected void onResume() {        super.onResume();        registerHomeKeyReceiver(this);    }    @Override    protected void onPause() {        unregisterHomeKeyReceiver(this);        super.onPause();    }

　　當然也可以根據需要在其他合適的時機註冊和登出.

 

參考資料

　　http://blog.csdn.net/way_ping_li/article/details/8953622

 

Android Home鍵監聽