android - 当我在父全屏活动上显示警报对话框时，我不想显示 SystemUI

Question

我有一个全屏活动，但是当我在其上方显示一个警报对话框时，系统 UI 显示（系统通知栏）。有谁能够帮我 ？我不希望它可见。出现警报对话框时，有什么方法可以隐藏系统通知栏不显示？

Answer 1

使用 AlertDialog.Builder 构建 AlertDialog 并创建 AlertDialog。
在调用 show() 之前，将对话框的 Window 标志设置为不可聚焦。
显示对话框后，在代表 AlertDialog 的窗口的 decorView 上设置 SystemUiVisibility 标志，并清除不可聚焦标志。

    AlertDialog.Builder adBuilder = new AlertDialog.Builder(this);
    AlertDialog alertDialog = adBuilder.setCancelable(false).
            setMessage("Turn ended, Click OK").
            setPositiveButton("OK", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialogInterface, int i) {
                }
            }).create();
    alertDialog.getWindow().setFlags(WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE, WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE);
    alertDialog.show();
    alertDialog.getWindow().getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_LOW_PROFILE
            | View.SYSTEM_UI_FLAG_FULLSCREEN
            | View.SYSTEM_UI_FLAG_LAYOUT_STABLE
            | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY
            | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
            | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION);
    alertDialog.getWindow().clearFlags(WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE);

现在，当显示 AlertDialog 时，SystemUI 元素不会出现。希望这可以帮助。

Answer 2

这对我有用，在 api 21 和 16 上测试过

 dialog.setOnShowListener(new DialogInterface.OnShowListener() {
        @Override
        public void onShow(DialogInterface dialog) {
            getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
        }
    });

Answer 3

实例化对话框时使用哪个上下文对象？

也许尝试使用您的活动？您可以通过将“this”作为上下文传递来做到这一点。

我知道有些人正在调用 getApplicationContext() 这不是（总是）正确的方法。

Answer 4

其他答案主要使用 View 中 setSystemUiVisibility() 方法的标志。但是，自 Android 11 起，此 API 已被弃用。

以下是使用新 API 显示/隐藏系统栏的代码片段，以及为向后兼容而弃用的代码片段：

fun Window.hideSystemUI() {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
        insetsController?.let {
            // Default behavior is that if navigation bar is hidden, the system will "steal" touches
            // and show it again upon user's touch. We just want the user to be able to show the
            // navigation bar by swipe, touches are handled by custom code -> change system bar behavior.
            // Alternative to deprecated SYSTEM_UI_FLAG_IMMERSIVE.
            it.systemBarsBehavior = WindowInsetsController.BEHAVIOR_SHOW_TRANSIENT_BARS_BY_SWIPE
            // make navigation bar translucent (alternative to deprecated
            // WindowManager.LayoutParams.FLAG_TRANSLUCENT_NAVIGATION)
            // - do this already in hideSystemUI() so that the bar
            // is translucent if user swipes it up
//                window.navigationBarColor = getColor(R.color.internal_black_semitransparent_light)
            // Finally, hide the system bars, alternative to View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
            // and SYSTEM_UI_FLAG_FULLSCREEN.
            it.hide(WindowInsets.Type.systemBars())
        }
    } else {
        // Enables regular immersive mode.
        // For "lean back" mode, remove SYSTEM_UI_FLAG_IMMERSIVE.
        // Or for "sticky immersive," replace it with SYSTEM_UI_FLAG_IMMERSIVE_STICKY
        @Suppress("DEPRECATION")
        decorView.systemUiVisibility = (
                // Do not let system steal touches for showing the navigation bar
                View.SYSTEM_UI_FLAG_IMMERSIVE
                        // Hide the nav bar and status bar
                        or View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
                        or View.SYSTEM_UI_FLAG_FULLSCREEN
                        // Keep the app content behind the bars even if user swipes them up
                        or View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
                        or View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN)
        // make navbar translucent - do this already in hideSystemUI() so that the bar
        // is translucent if user swipes it up
        @Suppress("DEPRECATION")
        addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_NAVIGATION)
    }
}


/**
 * Shows the system bars and returns back from fullscreen.
 * @see hideSystemUI
 * @see addSystemUIVisibilityListener
 */
fun Window.showSystemUI() {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
        // show app content in fullscreen, i. e. behind the bars when they are shown (alternative to
        // deprecated View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION and View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN)
        setDecorFitsSystemWindows(false)
        // finally, show the system bars
        insetsController?.show(WindowInsets.Type.systemBars())
    } else {
        // Shows the system bars by removing all the flags
        // except for the ones that make the content appear under the system bars.
        @Suppress("DEPRECATION")
        decorView.systemUiVisibility = (
                View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
                        or View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN)
    }
}