安卓。立即隐藏状态栏

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.WindowManager;

public class MainActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // 隐藏状态栏
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                             WindowManager.LayoutParams.FLAG_FULLSCREEN);
    }
}

// 恢复显示状态栏
getWindow().clearFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    // 隐藏状态栏
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                         WindowManager.LayoutParams.FLAG_FULLSCREEN);
    setContentView(R.layout.activity_main);
}