Disable status bar android

Hello bro use This one!

Use this code for hiding the status bar in your app and easy to use

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

If what u want is full screen activity, use this

public class sample extends AppCompatActivity {

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

        setFullScreen();

        //add your code

    }

    private void setFullScreen() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R){
            getWindow().getInsetsController().hide(WindowInsets.Type.statusBars() | WindowInsets.Type.statusBars());
            getWindow().getInsetsController().setSystemBarsBehavior(WindowInsetsController.BEHAVIOR_SHOW_TRANSIENT_BARS_BY_SWIPE);
        }else {
            getWindow().setFlags(LayoutParams.FLAG_FULLSCREEN,LayoutParams.FLAG_FULLSCREEN);
        }
    }
}

If you're saying that u don't status bar to open, then that isn't possible.

You can't show and hide native status bar of android, the system doesn't allow you to do that. But you can create your own customized status, then you can show it and hide it as you want. Here and example: custom_status.xml

    <com.google.android.material.card.MaterialCardView
        android:id="@+id/mToolbar_container"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginBottom="10dp"
        android:backgroundTint="@color/white"
        app:cardCornerRadius="0dp"
        app:cardElevation="0dp">

        <androidx.constraintlayout.widget.ConstraintLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="horizontal">

            <TextView
                android:id="@+id/textView2"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_gravity="center_vertical"
                android:layout_marginHorizontal="15dp"
                android:layout_marginVertical="15dp"
                android:layout_weight="1"
                android:ellipsize="end"
                android:maxLines="1"
                android:paddingBottom="2dp"
                android:textColor="@color/black"
                android:textSize="32sp"
                app:layout_constraintBottom_toBottomOf="@+id/backButton"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintStart_toEndOf="@+id/backButton"
                app:layout_constraintTop_toTopOf="@+id/backButton" />

            <ImageView
                android:id="@+id/backButton"
                android:layout_width="40dp"
                android:layout_height="40dp"
                android:layout_marginStart="15dp"
                android:layout_marginTop="20dp"
                android:background="@drawable/ic_circle_solid"
                android:backgroundTint="@color/quantum_grey100"
                android:padding="7dp"
                android:src="@drawable/ic_baseline_arrow_back_24"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toTopOf="parent" />

        </androidx.constraintlayout.widget.ConstraintLayout>
    </com.google.android.material.card.MaterialCardView>

in java code

public void onScrollStateChanged(AbsListView view, int scrollState) {
final ListView lw = getListView();

if (view.getId() == lw.getId()) {
    final int currentFirstVisibleItem = lw.getFirstVisiblePosition();

    if (currentFirstVisibleItem > mLastFirstVisibleItem) {
        mIsScrollingUp = false;
        //mToolbar_container visible
    } else if (currentFirstVisibleItem < mLastFirstVisibleItem) {
        mIsScrollingUp = true;
        //mToolbar_container gone
    }
} 

}