Hiding the navigation bar immediately on app launch

问题

Based on the following code snippets, I was able to hide the status bar right when the app launches, but not the navigation bar (the bar consisting of the back, home, and task manager buttons) since it hides later after MainActivity's thread finishes loading up:

Here's the manifest:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="dpark.sample2">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity
            android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

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

</manifest>

... here's the styles:

<resources>

    <!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.AppCompat">
        <!-- Customize your theme here. -->
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
        <item name="windowNoTitle">true</item>
        <item name="android:windowFullscreen">true</item>
    </style>

</resources>

... and MainActivity:

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    @Override
    public void onWindowFocusChanged(boolean hasFocus) {
        super.onWindowFocusChanged(hasFocus);
        if (hasFocus) {
            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
                            | View.SYSTEM_UI_FLAG_FULLSCREEN
                            | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY);
        }
    }
}

... How do I hide both bars from the start at the same time like a game or YouTube's full screen mode?

回答1:

Move this line of code to onCreate()-

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
                    | View.SYSTEM_UI_FLAG_FULLSCREEN
                    | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY);

回答2:

Im trying to solve this for my splash screen and no luck so far. But you can make things look better if you add this to your style theme:

<item name="android:windowTranslucentNavigation">true</item>

Navigation will be still visible, but translucent. This is how my theme looks like now:

<style name="SplashTheme" parent="Theme.MaterialComponents.DayNight.NoActionBar">
    <item name="android:windowBackground">@drawable/ps_splash_screen</item>
    <item name="android:windowNoTitle">true</item>
    <item name="android:windowFullscreen">true</item>
    <item name="android:windowTranslucentNavigation">true</item>
    <item name="android:windowContentOverlay">@null</item>
</style>

Good luck.

回答3:

Try this in your onCreate

 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
            getWindow().setFlags(WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS,
                    WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS);
        }

来源：https://stackoverflow.com/questions/41748014/hiding-the-navigation-bar-immediately-on-app-launch