CONTEXT MENU - POPUP TUY CHON MENU

- File main.xml : 

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout 

xmlns:android="http://schemas.android.com/apk/res/android"    

android:layout_width="fill_parent"    

android:layout_height="fill_parent"    

android:gravity="center"    

android:orientation="vertical" >

    <TextView        

android:layout_width="wrap_content"        

android:layout_height="wrap_content"        

android:text="Welcome to compiletimeerror.com" 

/>

    <Button        

android:id="@+id/btn"        

android:layout_width="wrap_content"        

android:layout_height="wrap_content"        

android:text="Long press me!" 

/>

</LinearLayout>

- File main.java : 

import android.app.Activity;
import android.os.Bundle;
import android.view.ContextMenu;
import android.view.MenuItem;
import android.view.View;
import android.view.ContextMenu.ContextMenuInfo;
import android.widget.Button;
import android.widget.Toast;

public class ManHinhChinh extends Activity {
    /** Called when the activity is first created. */    Button btn ;
    @Override    
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_man_hinh_chinh);

        btn = (Button) findViewById(R.id.btn);

        //registerForContextMenu(btn);        
        btn.setOnClickListener(new android.view.View.OnClickListener() {

            public void onClick(View v) {
                registerForContextMenu(v);
                v.showContextMenu();

            }
        });

    }
    @Override    
    public void onCreateContextMenu(ContextMenu menu, View v,
                                    ContextMenuInfo menuInfo) {
        super.onCreateContextMenu(menu, v, menuInfo);
        menu.setHeaderTitle("Menu Tùy Chọn");
        menu.add(0, v.getId(), 0, "Tùy Chọn 1");
        menu.add(0, v.getId(), 0, "Tùy Chọn 2");
        menu.add(0, v.getId(), 0, "Tùy Chọn 3");
        menu.add(0, v.getId(), 0, "Tùy Chọn 4");

    }
    @Override    
    public boolean onContextItemSelected(MenuItem item) {
        if (item.getTitle() == "Tùy Chọn 1") {
            Toast.makeText(this, "Action 1 invoked", Toast.LENGTH_SHORT).show();
        } else if (item.getTitle() == "Tùy Chọn 2") {
            Toast.makeText(this, "Action 2 invoked", Toast.LENGTH_SHORT).show();
        } else if (item.getTitle() == "Tùy Chọn 3") {
            Toast.makeText(this, "Action 3 invoked", Toast.LENGTH_SHORT).show();
        } else if (item.getTitle() == "Tùy Chọn 4") {
            Toast.makeText(this, "Action 4 invoked", Toast.LENGTH_SHORT).show();
        }
        else {
            return false;
        }
        return true;
    }

}