在经历了很长时间的失败后，我想出了自己的解决方案，这与其他开发者的做法非常相似。所以如果有人需要她的话。我的问题是，系统导航栏没有隐藏后调用。在我的例子中，我需要横屏，所以为了以防万一，注释那一行。 首先，创建风格

    <style name="FullscreenTheme" parent="AppTheme">
    <item name="android:actionBarStyle">@style/FullscreenActionBarStyle</item>
    <item name="android:windowActionBarOverlay">true</item>
    <item name="android:windowBackground">@null</item>
    <item name="metaButtonBarStyle">?android:attr/buttonBarStyle</item>
    <item name="metaButtonBarButtonStyle">?android:attr/buttonBarButtonStyle</item>
</style>

这是我的舱单

<activity
        android:name=".Splash"
        android:screenOrientation="landscape"
        android:configChanges="orientation|keyboard|keyboardHidden|screenLayout|screenSize"
        android:label="@string/app_name"
        android:theme="@style/SplashTheme">

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

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

    <activity
        android:name=".MainActivity"
        android:configChanges="orientation|keyboard|keyboardHidden|screenLayout|screenSize"
        android:screenOrientation="landscape"
        android:label="@string/app_name"
        android:theme="@style/FullscreenTheme">
    </activity>

这是我的spalsh活动

public class Splash extends Activity {
/** Duration of wait **/
private final int SPLASH_DISPLAY_LENGTH = 2000;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle icicle) {
    super.onCreate(icicle);
    setContentView(R.layout.splash_creen);

    /* New Handler to start the Menu-Activity
     * and close this Splash-Screen after some seconds.*/
    new Handler().postDelayed(new Runnable(){
        @Override
        public void run() {
            /* Create an Intent that will start the Menu-Activity. */
            Intent mainIntent = new Intent(Splash.this,MainActivity.class);
            Splash.this.startActivity(mainIntent);
            Splash.this.finish();
        }
    }, SPLASH_DISPLAY_LENGTH);
}

}

这是我主要的全屏活动。onSystemUiVisibilityChange这个方法是退出重要的，否则android主导航栏在调用后将保持不变，不再消失。很烦人的问题，但是这个函数解决了这个问题。

公共类MainActivity扩展了AppCompatActivity ｛

private View mContentView;
@Override
public void onResume(){
    super.onResume();

    mContentView.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);

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

    setContentView(R.layout.fullscreen2);
    ActionBar actionBar = getSupportActionBar();
    if (actionBar != null)
    {
        actionBar.hide();
    }
    mContentView = findViewById(R.id.fullscreen_content_text);
    mContentView.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);



    View decorView = getWindow().getDecorView();
    decorView.setOnSystemUiVisibilityChangeListener
            (new View.OnSystemUiVisibilityChangeListener()
            {
                @Override
                public void onSystemUiVisibilityChange(int visibility)
                {
                    System.out.println("print");

                    if ((visibility & View.SYSTEM_UI_FLAG_FULLSCREEN) == 0)
                    {
                        mContentView.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);
                    }
                    else
                    {

                        mContentView.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);

                        }
                }
            });

}

}

这是我的启动画面布局:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="fill_parent"
    android:layout_height="fill_parent">
    <ImageView android:id="@+id/splashscreen" android:layout_width="wrap_content"
        android:layout_height="fill_parent"
        android:background="@android:color/white"
        android:src="@drawable/splash"
        android:layout_gravity="center"/>
    <TextView android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Hello World, splash"/>
</LinearLayout>

This is my fullscreen layout
    <?xml version="1.0" encoding="utf-8"?>
    <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="#0099cc"
        >
        <TextView
            android:id="@+id/fullscreen_content_text"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:gravity="center"
            android:keepScreenOn="true"
            android:text="@string/dummy_content2"
            android:textColor="#33b5e5"
            android:textSize="50sp"
            android:textStyle="bold" />

    </FrameLayout>

我希望这对你有所帮助

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">

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

你可以通过编程来实现:

public class ActivityName extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // remove title
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
            WindowManager.LayoutParams.FLAG_FULLSCREEN);
        setContentView(R.layout.main);
    }
}

或者你也可以通过AndroidManifest.xml文件来实现:

<activity android:name=".ActivityName"
    android:label="@string/app_name"
    android:theme="@android:style/Theme.NoTitleBar.Fullscreen"/>

编辑:

如果你正在使用AppCompatActivity，那么你需要添加新的主题

<style name="Theme.AppCompat.Light.NoActionBar.FullScreen" parent="@style/Theme.AppCompat.Light.NoActionBar">
    <item name="android:windowNoTitle">true</item>
    <item name="android:windowActionBar">false</item>
    <item name="android:windowFullscreen">true</item>
    <item name="android:windowContentOverlay">@null</item>
</style>

然后使用它。

<activity android:name=".ActivityName"
    android:label="@string/app_name"
    android:theme="@style/Theme.AppCompat.Light.NoActionBar.FullScreen"/>

感谢https://stackoverflow.com/a/25365193/1646479

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);