Android 全屏覆盖，不带后退/主页/菜单按钮

我有这个功能在我的活动上显示一个全屏黑色覆盖。模仿屏蔽行为

private void showBlackOverlay() {
    Dialog dialog = new Dialog(this, android.R.style.Theme_Black_NoTitleBar_Fullscreen);
    dialog.show();
}

但仍然可以看到返回/主页/菜单按钮。我怎么能把它们藏起来？ 我也需要它在旧版本的android上工作

像这样试试

View decorView = dialog.getWindow().getDecorView();
// Hide both the navigation bar and the status bar.
// SYSTEM_UI_FLAG_FULLSCREEN is only available on Android 4.1 and higher, but as
// a general rule, you should design your app to hide the status bar whenever you
// hide the navigation bar.
int uiOptions = View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
              | View.SYSTEM_UI_FLAG_FULLSCREEN;
decorView.setSystemUiVisibility(uiOptions);

像这样试试

View decorView = dialog.getWindow().getDecorView();
// Hide both the navigation bar and the status bar.
// SYSTEM_UI_FLAG_FULLSCREEN is only available on Android 4.1 and higher, but as
// a general rule, you should design your app to hide the status bar whenever you
// hide the navigation bar.
int uiOptions = View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
              | View.SYSTEM_UI_FLAG_FULLSCREEN;
decorView.setSystemUiVisibility(uiOptions);

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据我所知，从Android 4.4 API级别19，您可以做到这一点。您可以在这里查看详细信息：

据我所知，从Android 4.4 API级别19，您可以做到这一点。您可以在此处查看详细信息：

尝试以下操作：

刚刚在我的Nexus7Android 4.4.2上尝试了这段代码，效果很好

public void onWindowFocusChanged(boolean hasFocus) {
    super.onWindowFocusChanged(hasFocus);
    if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.KITKAT) {
        if (hasFocus) {
            decorView
                    .setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
                            | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
                            | View.SYSTEM_UI_FLAG_FULLSCREEN
                            | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY);
        }
    }
}

试着这样做：

刚刚在我的Nexus7Android 4.4.2上尝试了这段代码，效果很好

public void onWindowFocusChanged(boolean hasFocus) {
    super.onWindowFocusChanged(hasFocus);
    if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.KITKAT) {
        if (hasFocus) {
            decorView
                    .setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
                            | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
                            | View.SYSTEM_UI_FLAG_FULLSCREEN
                            | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY);
        }
    }
}

---

如果我的回答对你有效，请接受。谢谢如果我的回答对你有效，请接受。谢谢DecorView是实际保持窗口背景可绘制的视图。从活动中调用getWindow.setBackgroundDrawable可以通过更改DecorView的背景drawable来更改窗口的背景。DecorView是实际保存窗口背景drawable的视图。从活动中调用getWindow.setBackgroundDrawable可通过更改DecorView的背景可绘制来更改窗口的背景。