只需将此代码粘贴到onCreate()方法中

requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
            WindowManager.LayoutParams.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

创建一个空活动，并在onCreate中添加两行。

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // full screen activity
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
        getSupportActionBar().hide();

        setContentView(R.layout.activity_main);
    }
    ...
}

如果你不想使用主题@android:style/ theme . notitlebar。因为你已经在使用你自己的主题，你可以使用android:windowFullscreen。

在AndroidManifest.xml:

<activity
  android:name=".ui.activity.MyActivity"
  android:theme="@style/MyTheme">
</activity>

在styles.xml:

<style name="MyTheme"  parent="your parent theme">
  <item name="android:windowNoTitle">true</item>
  <item name="android:windowFullscreen">true</item> 
</style>

充分沉浸:

private void askForFullScreen()
    {
        getActivity().getWindow().getDecorView().setSystemUiVisibility(
                View.SYSTEM_UI_FLAG_LAYOUT_STABLE
                        | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
                        | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
                        | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION // hide nav bar
                        | View.SYSTEM_UI_FLAG_FULLSCREEN // hide status bar
                        | View.SYSTEM_UI_FLAG_IMMERSIVE);
    }

脱离完全沉浸模式:

 private void moveOutOfFullScreen() {
        getActivity().getWindow().getDecorView().setSystemUiVisibility(
                View.SYSTEM_UI_FLAG_LAYOUT_STABLE
                        | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
                        | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN);
    }

对于安卓X

1. 透明状态栏

    window?.decorView?.systemUiVisibility = (View.SYSTEM_UI_FLAG_LAYOUT_STABLE
            or View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN)
    window.statusBarColor = Color.TRANSPARENT

2. 透明的状态栏和底部导航栏

    window.setFlags(
        WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS,
        WindowManager.LayoutParams.FLAG_LAYOUT_IN_SCREEN
    );

3.隐藏状态栏

API 30+推荐的Compat解决方案(包括向后兼容性)

  val windowInsetsController =
      WindowCompat.getInsetsController(window, window.decorView) ?: return
  windowInsetsController.systemBarsBehavior =
      WindowInsetsControllerCompat.BEHAVIOR_SHOW_TRANSIENT_BARS_BY_SWIPE
  windowInsetsController.hide(WindowInsetsCompat.Type.statusBars())

https://developer.android.com/training/system-ui/immersive

4. 隐藏状态栏和底部导航栏

消防级别30:

SystemUiVisibility标志已弃用。请改用WindowInsetsController。

和3一样。，只需使用WindowInsetsCompat.Type.systemBars()

    val actionBar: ActionBar? = supportActionBar
        if (actionBar != null) actionBar.hide()

    val windowInsetsController =
        WindowCompat.getInsetsController(window, window.decorView) ?: return
    windowInsetsController.systemBarsBehavior =
        WindowInsetsControllerCompat.BEHAVIOR_SHOW_TRANSIENT_BARS_BY_SWIPE
    windowInsetsController.hide(WindowInsetsCompat.Type.systemBars())

https://developer.android.com/training/system-ui/immersive

把这些代码放在哪里?

   override fun onCreate(savedInstanceState: Bundle?) {

        /*  Put above code here ..... */
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_slider)
   }

Note

我在Pixel 3A模拟器中检查了这段代码 可能自定义android操作系统不支持 set style <style name="主题。"全屏Theme.MaterialComponents.DayNight.NoActionBar“父= >