谢谢你的回答@克里斯蒂安，我得到了错误

android.util.AndroidRuntimeException:必须调用requestFeature() 添加内容前

我用

@Override
protected void onCreate(Bundle savedInstanceState) {

    requestWindowFeature(Window.FEATURE_NO_TITLE);

    super.onCreate(savedInstanceState);

    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);

    setContentView(R.layout.activity_login);

    -----
    -----
}

如果你使用AppCompat和ActionBarActivity，那么使用这个

getSupportActionBar () hide ();

谢谢你的回答@克里斯蒂安，我得到了错误

android.util.AndroidRuntimeException:必须调用requestFeature() 添加内容前

我用

@Override
protected void onCreate(Bundle savedInstanceState) {

    requestWindowFeature(Window.FEATURE_NO_TITLE);

    super.onCreate(savedInstanceState);

    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);

    setContentView(R.layout.activity_login);

    -----
    -----
}

截至2022年

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
        window.decorView.windowInsetsController?.hide(WindowInsets.Type.systemBars())
    } else {
        @Suppress("DEPRECATION") // Older API support
        window.decorView.systemUiVisibility = (View.SYSTEM_UI_FLAG_IMMERSIVE
                or View.SYSTEM_UI_FLAG_LAYOUT_STABLE
                or View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
                or View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
                or View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
                or View.SYSTEM_UI_FLAG_FULLSCREEN)
    }

在onCreate()中的setContentView之后使用这个方法，并通过getWindow()传递Window对象。

    public void makeActivityFullScreen(Window window){
    View decorView = window.getDecorView();
    //        int uiOptions = View.SYSTEM_UI_FLAG_FULLSCREEN;
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
       window.getAttributes().layoutInDisplayCutoutMode = WindowManager.LayoutParams.LAYOUT_IN_DISPLAY_CUTOUT_MODE_SHORT_EDGES;
    }
    decorView.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
    );
}

此代码也将适用于缺口屏幕。要检查缺口全屏，你需要安卓P，但如果你有一个缺口显示手机，然后去设置->显示设置->应用程序显示比例->选择你的应用程序->有两个安全的选项是显示和全屏，请选择全屏并运行应用程序，你可以看到缺口的全屏也没有安卓派

科特林

遵循谷歌文档，有一个简单的方法:

override fun onWindowFocusChanged(hasFocus: Boolean) {
super.onWindowFocusChanged(hasFocus)
if (hasFocus) hideSystemUI() }


private fun hideSystemUI() {
// 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
window.decorView.systemUiVisibility = (View.SYSTEM_UI_FLAG_IMMERSIVE
        // Set the content to appear under the system bars so that the
        // content doesn't resize when the system bars hide and show.
        or View.SYSTEM_UI_FLAG_LAYOUT_STABLE
        or View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
        or View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
        // Hide the nav bar and status bar
        or View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
        or View.SYSTEM_UI_FLAG_FULLSCREEN)      }


// Shows the system bars by removing all the flags
// except for the ones that make the content appear under the system bars.
private fun showSystemUI() {
window.decorView.systemUiVisibility = 
(View.SYSTEM_UI_FLAG_LAYOUT_STABLE
        or View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
        or View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN)       }

谷歌文档