隐藏Activity标题栏

package logd.log.com.logddemo;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;

public class MainActivity extends AppCompatActivity {

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

        if (getSupportActionBar() != null){
            getSupportActionBar().hide();
        }

        setContentView(R.layout.activity_main);
        Log.v("MainActivity","on created executed");
    }
}