Android 长按系统返回键监听

Question

我想在 android 系统后退按钮被长按时添加一个监听器，即 Activity.onBackPressed

的长按版本

这只需要在我的应用程序可见时工作。

Chrome 长按后退时显示历史菜单，所以它一定是可能的，但找不到它的钩子。谢谢

Answer 1

您可以尝试覆盖 Activity 中的 onKeyLongPress 方法。

@Override
public boolean onKeyLongPress(int keyCode, KeyEvent event) {
    if (keyCode == KeyEvent.KEYCODE_BACK) {
        System.out.println("Back button long pressed");
        return true;
    }
    return super.onKeyLongPress(keyCode, event);
}

Answer 2

希望下面的想法可行！！！

在您的 activity

中添加以下代码

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    if (keyCode == KeyEvent.KEYCODE_BACK) {
        //This event will be triggered after 1 second. 
        //In case if you move out of KEYCODE_BACK, onKeyUp event will be triggered and this event will be cancelled 
        handler.postDelayed(mLongPressed, 1000); 
        return true;
    }
    return super.onKeyDown(keyCode, event);
}

@Override
public boolean onKeyUp(int keyCode, KeyEvent event) {
    handler.removeCallbacks(mLongPressed);
    return super.onKeyUp(keyCode, event);
}

处理程序代码：

final Handler handler = new Handler();
Runnable mLongPressed = new Runnable() {
    public void run() {
        Log.i("Activity", "Long press detected").
       //Add your code
    }
};

Answer 3

你可以看看firefox是如何实现长按后退的。

https://github.com/mozilla-mobile/fenix/blob/master/app/src/main/java/org/mozilla/fenix/HomeActivity.kt

他们使用 onKeyDown/onKeyUp 和 onKeyLongPress 来实现它。

两者都被使用的原因是因为

Android N and Huawei devices have broken onKeyLongPress events for the back button, so we instead implement the long press behavior ourselves

For short presses, we cancel the callback in onKeyUp

For long presses, the normal keyPress is marked as cancelled, hence won't be handled elsewhere (but Android still provides the haptic feedback), and the long press action is run

下面是它们的实现。

// See onKeyDown for why this is necessary
private var backLongPressJob: Job? = null

private fun shouldUseCustomBackLongPress(): Boolean {
    val isAndroidN =
        Build.VERSION.SDK_INT == Build.VERSION_CODES.N || Build.VERSION.SDK_INT == Build.VERSION_CODES.N_MR1
    // Huawei devices seem to have problems with onKeyLongPress
    // See https://github.com/mozilla-mobile/fenix/issues/13498
    val isHuawei = Build.MANUFACTURER.equals("huawei", ignoreCase = true)
    return isAndroidN || isHuawei
}

private fun handleBackLongPress(): Boolean {
    supportFragmentManager.primaryNavigationFragment?.childFragmentManager?.fragments?.forEach {
        if (it is OnBackLongPressedListener && it.onBackLongPressed()) {
            return true
        }
    }
    return false
}

final override fun onKeyDown(keyCode: Int, event: KeyEvent?): Boolean {
    // Inspired by https://searchfox.org/mozilla-esr68/source/mobile/android/base/java/org/mozilla/gecko/BrowserApp.java#584-613
    // Android N and Huawei devices have broken onKeyLongPress events for the back button, so we
    // instead implement the long press behavior ourselves
    // - For short presses, we cancel the callback in onKeyUp
    // - For long presses, the normal keypress is marked as cancelled, hence won't be handled elsewhere
    //   (but Android still provides the haptic feedback), and the long press action is run
    if (shouldUseCustomBackLongPress() && keyCode == KeyEvent.KEYCODE_BACK) {
        backLongPressJob = lifecycleScope.launch {
            delay(ViewConfiguration.getLongPressTimeout().toLong())
            handleBackLongPress()
        }
    }
    return super.onKeyDown(keyCode, event)
}

final override fun onKeyUp(keyCode: Int, event: KeyEvent?): Boolean {
    if (shouldUseCustomBackLongPress() && keyCode == KeyEvent.KEYCODE_BACK) {
        backLongPressJob?.cancel()
    }
    return super.onKeyUp(keyCode, event)
}

final override fun onKeyLongPress(keyCode: Int, event: KeyEvent?): Boolean {
    // onKeyLongPress is broken in Android N so we don't handle back button long presses here
    // for N. The version check ensures we don't handle back button long presses twice.
    if (!shouldUseCustomBackLongPress() && keyCode == KeyEvent.KEYCODE_BACK) {
        return handleBackLongPress()
    }
    return super.onKeyLongPress(keyCode, event)
}

Android 长按系统返回键监听

Android long press system back button listener

android

events

back

onlongclicklistener

long-click