android在activity中去掉标题栏

package com.goodness.goodness;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Window;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
//        去掉TitleBar（需要放到setContentView上面）
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.activity_main);
    }
}