Android菜单应用（Menu）

package com.example.menu;

import android.app.Activity;
import android.app.ActionBar;
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.os.Build;

public class MainActivity extends Activity {

final int ok=1;
final int cancle=2;
final int about=3;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

if (savedInstanceState == null) {
getFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment()).commit();
}
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {

menu.add(0,ok,0,"开始");
menu.add(0,cancle,0,"取消");
Menu file=menu.addSubMenu(0,about,0,"关于");

// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu, file);
return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
switch(id){
case ok:
this.setTitle("开始");
return true;
case cancle:
this.setTitle("取消");
return true;
case about:
this.setTitle("关于");
return true;
case R.id.help:
this.setTitle("帮助信息");
return true;
case R.id.our:
this.setTitle("联系我们");
return true;

}

return super.onOptionsItemSelected(item);
}

/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {

public PlaceholderFragment() {
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container,
false);

return rootView;
}
}

}