浅谈PopupWindow弹出菜单

实现将一个View显示在某一位置,而且是浮于当前窗口

首先要有一个要显示的view的布局，可以是任意View，包括ViewGroup

 <?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:background="#d3d3d3"
     android:gravity="center_horizontal"
     android:orientation="vertical" >

     <TextView
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:gravity="center"
         android:id="@+id/textView"
         android:text="文本内容"
         />
 </LinearLayout>

然后主界面布局文件

 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     tools:context=".MainActivity" >

     <LinearLayout
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:orientation="horizontal"
         >
         <!-- 区域 -->
         <Button
             android:layout_width="0dp"
             android:layout_weight=""
             android:gravity="center"
             android:background="#0000"
             android:layout_height="wrap_content"
             android:text="区域"
             android:drawableRight="@drawable/title_bar_arrow_nor"
             android:id="@+id/btn_1"
             />
         <!-- 类别 -->
         <Button
             android:background="#0000"
             android:layout_width="0dp"
             android:layout_weight=""
             android:layout_height="wrap_content"
             android:text="类别"
             android:drawableRight="@drawable/title_bar_arrow_nor"
             android:id="@+id/btn_2"
             />

         <!-- 价格 -->
         <Button
             android:background="#0000"
             android:layout_width="0dp"
             android:layout_weight=""
             android:layout_height="wrap_content"
             android:text="价格"
             android:drawableRight="@drawable/title_bar_arrow_nor"
             android:id="@+id/btn_3"
             />

         <!-- 更多 -->
         <Button
             android:background="#0000"
             android:layout_width="0dp"
             android:layout_weight=""
             android:layout_height="wrap_content"
             android:text="更多"
             android:drawableRight="@drawable/title_bar_arrow_nor"
             android:id="@+id/btn_4"
             />

     </LinearLayout>

 </RelativeLayout>

主activity

 package com.example.aaa;

 import android.app.Activity;
 import android.os.Bundle;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.view.ViewGroup;
 import android.widget.Button;
 import android.widget.PopupWindow;
 import android.widget.TextView;

 public class MainActivity extends Activity implements OnClickListener {

     private PopupWindow pop; 

     private Button btn1;
     private Button btn2;
     private Button btn3;
     private Button btn4;

     private TextView text;

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

         initView();
         initPopWindow();

     }

     private void initView() {
         // TODO Auto-generated method stub
         btn1 = (Button) findViewById(R.id.btn_1);
         btn2 = (Button) findViewById(R.id.btn_2);
         btn3 = (Button) findViewById(R.id.btn_3);
         btn4 = (Button) findViewById(R.id.btn_4);
         btn1.setOnClickListener(this);
         btn2.setOnClickListener(this);
         btn3.setOnClickListener(this);
         btn4.setOnClickListener(this);
     }

     private void initPopWindow() {
         // TODO Auto-generated method stub
         //根据layout创建弹出界面
         view = this.getLayoutInflater().inflate(R.layout.popup_window, null);
         pop = new PopupWindow(view, ViewGroup.LayoutParams.FILL_PARENT,
                 ViewGroup.LayoutParams.WRAP_CONTENT);
         text = (TextView) view.findViewById(R.id.textView);

         pop.setOutsideTouchable(true);
         view.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
                 // TODO Auto-generated method stub
                 pop.dismiss();
             }
         });  

     }

     @Override
     public void onClick(View v) {
         // TODO Auto-generated method stub
         switch (v.getId()) {
         case R.id.btn_1:
             text.setText("区域");
             if(pop.isShowing())
                 pop.dismiss();
             else
                 pop.showAsDropDown(v);
             break;
         case R.id.btn_2:
             text.setText("类别");
             if(pop.isShowing())
                 pop.dismiss();
             else
             pop.showAsDropDown(v);
             break;
         case R.id.btn_3:
             text.setText("价格");
             if(pop.isShowing())
                 pop.dismiss();
             else
             pop.showAsDropDown(v);
             break;
         case R.id.btn_4:
             text.setText("更多");
             if(pop.isShowing())
                 pop.dismiss();
             else
             pop.showAsDropDown(v);
             break;

         default:
             break;
         }
     }

 }

出现位置的几个方法

showAsDropDown(View anchor)：相对某个控件的位置（正左下方），无偏移
showAsDropDown(View anchor, int xoff, int yoff)：相对某个控件的位置，有偏移
showAtLocation(View parent, int gravity, int x, int y)：相对于父控件的位置（例如正中央Gravity.CENTER，下方Gravity.BOTTOM等），可以设置偏移或无偏移

效果图：