import androidx.core.view.WindowInsetsCompat.Type

fun Activity.fullscreen() {
    with(WindowInsetsControllerCompat(window, window.decorView)) {
        systemBarsBehavior = WindowInsetsControllerCompat.BEHAVIOR_SHOW_BARS_BY_SWIPE
        hide(Type.systemBars())
    }
}

fun Activity.exitFullscreen() {
    WindowInsetsControllerCompat(window, window.decorView).show(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);
}

小心

requestWindowFeature(Window.FEATURE_NO_TITLE);

如果您正在使用任何方法设置操作栏如下:

getSupportActionBar().setHomeButtonEnabled(true);

它将导致一个空指针异常。

AndroidManifest.xml

<activity ...
          android:theme="@style/FullScreenTheme"
    >
</activity>

I.你的主应用的主题是theme . appcompat . light . darkactionbar

隐藏ActionBar / StatusBar style.xml

<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
    ...
</style>

<style name="FullScreenTheme" parent="AppTheme">
    <!--this property will help hide the ActionBar-->
    <item name="windowNoTitle">true</item>
    <!--currently, I don't know why we need this property since use windowNoTitle only already help hide actionbar. I use it because it is used inside Theme.AppCompat.Light.NoActionBar (you can check Theme.AppCompat.Light.NoActionBar code). I think there are some missing case that I don't know-->
    <item name="windowActionBar">false</item>
    <!--this property is used for hiding StatusBar-->
    <item name="android:windowFullscreen">true</item>
</style>

隐藏系统导航栏

public class MainActivity extends AppCompatActivity {

    protected void onCreate(Bundle savedInstanceState) {
        getWindow().getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_HIDE_NAVIGATION);
        setContentView(R.layout.activity_main)
        ...
    }
 }

2你的主应用主题是theme . appcompat . light . noactionbar

隐藏ActionBar / StatusBar style.xml

<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
    ...
</style>

<style name="FullScreenTheme" parent="AppTheme">
    <!--don't need any config for hide ActionBar because our apptheme is NoActionBar-->
    <!--this property is use for hide StatusBar-->
    <item name="android:windowFullscreen">true</item> // 
</style>

隐藏系统导航栏

类似于theme。appcompat。light。darkactionbar。

演示

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)
    }

import androidx.core.view.WindowInsetsCompat.Type

fun Activity.fullscreen() {
    with(WindowInsetsControllerCompat(window, window.decorView)) {
        systemBarsBehavior = WindowInsetsControllerCompat.BEHAVIOR_SHOW_BARS_BY_SWIPE
        hide(Type.systemBars())
    }
}

fun Activity.exitFullscreen() {
    WindowInsetsControllerCompat(window, window.decorView).show(Type.systemBars())
}