PopupWindow的使用

简单理解该组件就是类似弹出层的一种android组件，这种组件类似QQ的状态修改的弹出，下面就来看下这类弹出窗怎么实现

1.对于弹出窗的内容，简单的做法就是写一个布局xml文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView  
    android:id="@+id/popstatus"
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:text="选择用户状态"
    />
 <RadioGroup
      android:id="@+id/changestatus"
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:orientation="vertical"
      android:checkedButton="@+id/online"
     >
     <RadioButton
        android:id="@+id/online"
        android:text="在线"
        />
       <RadioButton
        android:id="@+id/offline"
        android:text="离线"
        />
         <RadioButton
        android:id="@+id/hidden"
        android:text="隐身"
        />
 </RadioGroup>
 
</LinearLayout>

2.下面就是主界面的配置文件了，这里就定义一个textview和一个按钮，点击按钮就出现弹出窗，点击单选按钮textview的内容随之改变

（1）读取布局文件

（2）实例化PopupWindow，添加单选按钮事件处理

下面是主界面文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView  
    android:id="@+id/status"
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:text="在线"
    />
   <Button
   android:id="@+id/updatestatus"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="修改状态"/>
</LinearLayout>

下面则是最主要的逻辑代码

package org.lxh.popwin;

import android.app.Activity;
import android.os.Bundle;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.Button;
import android.widget.PopupWindow;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.TextView;

public class PopwinActivity extends Activity {
	private Button updatestatus = null;
	private PopupWindow popWin = null;
	private View view = null;
	private RadioGroup changestatus = null;
	private TextView status = null;

	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		status = (TextView) this.findViewById(R.id.status);
		updatestatus = (Button) this.findViewById(R.id.updatestatus);

		updatestatus.setOnClickListener(new View.OnClickListener() {

			public void onClick(View v) {
				LayoutInflater flate = LayoutInflater.from(PopwinActivity.this);
				view = flate.inflate(R.layout.popwin, null);
				//实例化PopupWindow
				popWin = new PopupWindow(view, 300, 200);
				changestatus = (RadioGroup) view
						.findViewById(R.id.changestatus);
				// 单选改变事件
				changestatus
						.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {

							public void onCheckedChanged(RadioGroup group,
									int checkedId) {
								// 取得单选按钮
								RadioButton rButton = (RadioButton) view
										.findViewById(group
												.getCheckedRadioButtonId());
								status.setText(rButton.getText().toString());
								//关闭弹出窗口
								popWin.dismiss();
							}
						});
				//显示弹出窗口
				popWin.showAtLocation(updatestatus, Gravity.CENTER, 0, 0);
			}
		});

	}
}

很简单吧，看下效果图吧