How to Hide the System Bar

How to hide status bar in android in just one activity

If you want to remove status bar then use this before setContentView(layout) in onCreateView method

    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
    WindowManager.LayoutParams.FLAG_FULLSCREEN);

credits

How do I hide the status bar in my Android 11 app?

When your device is API-30 (Android 11; minSdkVersion 30) or later , setSystemUiVisibility is deprecated and you can use the newly introduced WindowInsetsController instead. (And note that you cannot use WindowInsetsController on API-29 or earlier).

So the official reference says:

This method was deprecated in API level 30.
SystemUiVisibility flags are deprecated. Use WindowInsetsController instead.

You should use WindowInsetsController class.

in Kotlin:

window.decorView.windowInsetsController!!.hide(
    android.view.WindowInsets.Type.statusBars()
)

in Java:

getWindow().getDecorView().getWindowInsetsController().hide(
    android.view.WindowInsets.Type.statusBars()
);

If you also want to hide NavigationBar:

in Kotlin:

window.decorView.windowInsetsController!!.hide(
    android.view.WindowInsets.Type.statusBars()
            or android.view.WindowInsets.Type.navigationBars()
)

in Java:

getWindow().getDecorView().getWindowInsetsController().hide(
    android.view.WindowInsets.Type.statusBars()
            | android.view.WindowInsets.Type.navigationBars()
);

is it possible to hide the system bar

You can't hide it but you can disable it, except home. For that you can give your application as home category and let the user choose.

<category android:name="android.intent.category.HOME" />

Rest all can be disable.

add this in manifest.

<uses-permission android:name="android.permission.EXPAND_STATUS_BAR"/>

inside onCreate()

this.requestWindowFeature(Window.FEATURE_NO_TITLE); 
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
    setContentView(R.layout.activity_home);
    View v = findViewById(R.id.home_view);
    v.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LOW_PROFILE);

where home_view is the parent view of xml file.

 @Override
     public boolean onKeyDown(int keyCode, KeyEvent event) {
            return false;
        }

 public void onWindowFocusChanged(boolean hasFocus)
     {
             try
             {
                if(!hasFocus)
                {
                     Object service  = getSystemService("statusbar");
                     Class<?> statusbarManager = Class.forName("android.app.StatusBarManager");
                     Method collapse = statusbarManager.getMethod("collapse");
                     collapse .setAccessible(true);
                     collapse .invoke(service);
                }
             }
             catch(Exception ex)
             {
             }
     }

How to hide Android StatusBar in Flutter

SystemChrome.setEnabledSystemUIOverlays([]) should do what you want.

You can bring it back with SystemChrome.setEnabledSystemUIOverlays(SystemUiOverlay.values).

Import it using

import 'package:flutter/services.dart';

Update answer (from Flutter 2.5 or latest):

SystemChrome.setEnabledSystemUIMode(SystemUiMode.leanBack);

Or you can use another options like:

SystemChrome.setEnabledSystemUIMode(SystemUiMode.manual, overlays: [
  SystemUiOverlay.bottom
]);  // to hide only bottom bar

Then when you need to re-show it (like when dispose) use this:

  @override
  void dispose() {
    super.dispose();

    SystemChrome.setEnabledSystemUIMode(SystemUiMode.manual, overlays: SystemUiOverlay.values);  // to re-show bars

  }

Android - hide status and navigation bar completely for an app with nav drawer and app bar

Update

The issue was with your layout file. I just set android:fitsSystemWindows=false to fix the issue. I made a pull request to your repo, which I think solves your issue.

Sample Image

You should follow the following official documentations:

Hide the status bar
Hide the navigation bar

Hide the Status Bar on Android 4.0 and Lower

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // If the Android version is lower than Jellybean, use this call to hide
        // the status bar.
        if (Build.VERSION.SDK_INT < 16) {
            getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                    WindowManager.LayoutParams.FLAG_FULLSCREEN);
        }
        setContentView(R.layout.activity_main);
    }
    ...
}

Hide the Status Bar on Android 4.1 and Higher

    View decorView = getWindow().getDecorView();
    // Hide the status bar.
    int uiOptions = View.SYSTEM_UI_FLAG_FULLSCREEN;
    decorView.setSystemUiVisibility(uiOptions);
    // Remember that you should never show the action bar if the
    // status bar is hidden, so hide that too if necessary.
    ActionBar actionBar = getActionBar();
    actionBar.hide();

Hide the Navigation Bar

    View decorView = getWindow().getDecorView();
    // Hide both the navigation bar and the status bar.
    // SYSTEM_UI_FLAG_FULLSCREEN is only available on Android 4.1 and higher, but as
    // a general rule, you should design your app to hide the status bar whenever you
    // hide the navigation bar.
    int uiOptions = View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
                  | View.SYSTEM_UI_FLAG_FULLSCREEN;
    decorView.setSystemUiVisibility(uiOptions);