关于程序信息，Menu功能菜单程序设计

package com.wzc.ex03_17;

import android.content.DialogInterface;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;

public class MainActivity extends AppCompatActivity {

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

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        menu.add(0,0,0,R.string.app_about);
        menu.add(0,1,1,R.string.str_exit);
        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {

        super.onOptionsItemSelected(item);
        switch (item.getItemId()){
            case 0:
                // System.out.println(item.getItemId());
                 wzcopenOptionsDialog();
                break;
            case 1:
                wzcexitOptionsDialog();
                break;
        }
        return true;
    }

    private void wzcexitOptionsDialog() {
        new AlertDialog.Builder(this)
                .setTitle(R.string.str_exit)
                .setMessage(R.string.str_exit_words)
                .setPositiveButton(R.string.str_exit,
                        new DialogInterface.OnClickListener(){
                            @Override
                            public void onClick(DialogInterface dialogInterface, int i) {
                                finish();
                            }
                        }
                        ).show();
    }

    private void wzcopenOptionsDialog() {
        new AlertDialog.Builder(this)
                .setTitle(R.string.app_about)
                .setMessage(R.string.app_about_msg)
                .setPositiveButton(R.string.str_ok,
                        new DialogInterface.OnClickListener(){
                            @Override
                            public void onClick(DialogInterface dialogInterface, int i) {

                            }
                        }
                        ).show();
    }
}