用kotlin是这样做的:

class LoginActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_login)
        window.decorView.systemUiVisibility =
                View.SYSTEM_UI_FLAG_LAYOUT_STABLE or
                View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN or
                View.SYSTEM_UI_FLAG_FULLSCREEN

    }
}

身临其境的模式

沉浸式模式适用于用户需要与屏幕进行大量交互的应用程序。例如游戏、浏览图库中的图像或阅读分页内容(如书籍或演示文稿中的幻灯片)。为此，只需添加这几行:

View.SYSTEM_UI_FLAG_HIDE_NAVIGATION or
View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION

粘性身临其境

在常规的沉浸式模式下，每当用户从边缘滑动时，系统都会负责显示系统条——你的应用程序甚至不会意识到这个手势发生了。因此，如果用户可能真的需要从屏幕边缘滑动作为主要应用体验的一部分——比如在玩一款需要大量滑动的游戏或使用绘图应用时——你应该启用“粘性”沉浸模式。

View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY

有关更多信息:启用全屏模式

如果你使用键盘，有时会发生状态栏显示时，键盘显示。在这种情况下，我通常将此添加到我的style xml

styles.xml

<style name="FullScreen" parent="AppTheme">
    <item name="android:windowFullscreen">true</item>
</style>

还有这一行到我的载货单上

<activity
        android:name=".ui.login.LoginActivity"
        android:label="@string/title_activity_login"
        android:theme="@style/FullScreen">

提示:使用getWindow().setLayout()会搞砸你的全屏显示!注意，这个方法的文档说:

设置窗口的宽度和高度布局参数… 你可以把它们改成……用于制作非全屏窗口的绝对值。

http://developer.android.com/reference/android/view/Window.html#setLayout%28int,%20int%29

For my purposes, I found that I had to use setLayout with absolute parameters to resize my full screen window correctly. Most of the time, this worked fine. It was called by an onConfigurationChanged() event. There was a hiccup, however. If the user exited the app, changed the orientation, and reentered, it would lead to firing off my code which included setLayout(). During this re-entry time window, my status bar (which was hidden by the manifest) would be made to re-appear, but at any other time setLayout() would not cause this! The solution was to add an additional setLayout() call after the one with the hard values like so:

       public static void setSize( final int width, final int height ){
//DO SOME OTHER STUFF...
            instance_.getWindow().setLayout( width, height );
            // Prevent status bar re-appearance
            Handler delay = new Handler();
            delay.postDelayed( new Runnable(){ public void run() {
                instance_.getWindow().setLayout(
                    WindowManager.LayoutParams.FILL_PARENT,
                    WindowManager.LayoutParams.FILL_PARENT );
            }}, FILL_PARENT_ON_RESIZE_DELAY_MILLIS );
        }

然后，窗口正确地调整大小，状态栏不会重新出现，不管触发这一事件。

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

getSupportActionBar () hide ();

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

从mozilla找到解决方案，他们在这里做了一个扩展库

如果链接中断，这里是代码

/**
 * Retrieves a {@link WindowInsetsControllerCompat} for the top-level window decor view.
 */
fun Window.getWindowInsetsController(): WindowInsetsControllerCompat {
    return WindowInsetsControllerCompat(this, this.decorView)
}


/**
 * Attempts to call immersive mode using the View to hide the status bar and navigation buttons.
 * @param onWindowFocusChangeListener optional callback to ensure immersive mode is stable
 * Note that the callback reference should be kept by the caller and be used for [exitImmersiveModeIfNeeded] call.
 */
fun Activity.enterToImmersiveMode(
    onWindowFocusChangeListener: ViewTreeObserver.OnWindowFocusChangeListener? = null
) {
    window.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON)
    window.getWindowInsetsController().apply {
        hide(WindowInsetsCompat.Type.systemBars())
        systemBarsBehavior = WindowInsetsControllerCompat.BEHAVIOR_SHOW_TRANSIENT_BARS_BY_SWIPE
    }

    // We need to make sure system bars do not become permanently visible after interactions with content
    // see https://github.com/mozilla-mobile/fenix/issues/20240
    onWindowFocusChangeListener?.let {
        window.decorView.viewTreeObserver?.addOnWindowFocusChangeListener(it)
    }
}

/**
 * Attempts to come out from immersive mode using the View.
 * @param onWindowFocusChangeListener optional callback to ensure immersive mode is stable
 * Note that the callback reference should be kept by the caller and be the same used for [enterToImmersiveMode] call.
 */
@Suppress("DEPRECATION")
fun Activity.exitImmersiveModeIfNeeded(
    onWindowFocusChangeListener: ViewTreeObserver.OnWindowFocusChangeListener? = null
) {
    if (WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON and window.attributes.flags == 0) {
        // We left immersive mode already.
        return
    }
    onWindowFocusChangeListener?.let {
        window.decorView.viewTreeObserver?.removeOnWindowFocusChangeListener(it)
    }
    window.clearFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON)
    window.getWindowInsetsController().apply {
        show(WindowInsetsCompat.Type.systemBars())
    }
}

在AndroidManifest.xml文件:

<activity
    android:name=".Launch"
    android:label="@string/app_name"
    android:theme="@android:style/Theme.NoTitleBar.Fullscreen" > <!-- This line is important -->

    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity>  

或者在Java代码中:

protected void onCreate(Bundle savedInstanceState){
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
}