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="1"
            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="1"
            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="1"
            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="1"
            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：