popupMenu-----弹出菜单

 import android.os.Bundle;

 import android.app.Activity;

 import android.graphics.Color;

 import android.view.Menu;

 import android.view.MenuItem;

 import android.view.View;

 import android.widget.PopupMenu;

 import android.widget.PopupMenu.OnMenuItemClickListener;

 import android.widget.TextView;

 public class MainActivity extends Activity {

     private TextView textView;

     private float fontSize =15;

     @Override

     protected void onCreate(Bundle savedInstanceState) {

         super.onCreate(savedInstanceState);

         setContentView(R.layout.activity_main);

         textView = (TextView) findViewById(R.id.textView);

     }

     //弹出菜单是3.0开始出现的，所以api最低为11

     public void btnClick(View v)

     {

         //第二个参数是弹出菜单显示的参考位置,通常在参考视图的下边显示

         //创建一个弹出菜单对象

         PopupMenu  pop = new PopupMenu(this, v);

         //给菜单添加菜单项

         getMenuInflater().inflate(R.menu.main, pop.getMenu());

         //给菜单项添加事件监听

         pop.setOnMenuItemClickListener(new OnMenuItemClickListener() {

             @Override

             public boolean onMenuItemClick(MenuItem item) {

                 switch(item.getItemId())

                 {

                     case R.id.action_add:

                         fontSize+=5;

                         textView.setTextSize(fontSize);

                         break;

                     case R.id.action_sub:

                         fontSize-=5;

                         textView.setTextSize(fontSize);

                         break;

                     case R.id.action_background:

                         int red = (int)(Math.random()*256);

                         int green = (int)(Math.random()*256);

                         int blue = (int)(Math.random()*256);

                         textView.setBackgroundColor(Color.rgb(red, green, blue));

                         break;

                 }

                 return false;

             }

         });

         //显示菜单

         pop.show();

     }

 }

MainActivity

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

      <item

         android:id="@+id/action_add"

         android:orderInCategory="100"

         android:showAsAction="never"

         android:title="放大字体"/>

     <item

         android:id="@+id/action_sub"

         android:orderInCategory="100"

         android:showAsAction="never"

         android:title="缩小字体"/>

     <item

         android:id="@+id/action_background"

         android:orderInCategory="100"

         android:showAsAction="never"

         android:title="改变背景颜色"/>

 </menu>

menu_main