MainActivity.java

package cn.demo.videolist;

import android.content.pm.ActivityInfo;
import android.content.res.Configuration;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.KeyEvent;
import android.view.Window;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initActions();
    }

    private void initActions() {

    }

    @Override
    public boolean onKeyUp(int keyCode, KeyEvent event) {
        if (keyCode == KeyEvent.KEYCODE_BACK) {
            if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE) {
                setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
                return true;
            }
        }
        return super.onKeyUp(keyCode, event);
    }
}