本文实例介绍一下PopupWindow对话框。PopupWindow是阻塞对话框，只有在外部线程 或者 PopupWindow本身做退出操作才可以执行。PopupWindow完全依赖Layout做外观，在常见的开发中，PopupWindow应该会与AlertDialog常混用。

先贴出本例中运行的结果图：

main.xml的源码如下：

<?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" ><Button android:id="@+id/Button01" android:layout_height="wrap_content" android:layout_width="fill_parent" android:text="PopupWindow演示"></Button></LinearLayout>

下图所示是PopupWindow弹出的截图，这里的PopupWindow是个登录框，点“确定”则自动填写，点“取消”则关闭PopupWindow。

popupwindow.xml的源码如下：

<?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="wrap_content" android:orientation="vertical" android:background="#000000"> <TextView android:id="@+id/username_view" android:layout_height="wrap_content" android:layout_marginLeft="20dip" android:layout_marginRight="20dip" android:text="用户名" android:textAppearance="?android:attr/textAppearanceMedium" android:layout_width="fill_parent"/> <EditText android:id="@+id/username_edit" android:layout_height="wrap_content" android:layout_width="fill_parent" android:layout_marginLeft="20dip" android:layout_marginRight="20dip" android:capitalize="none" android:textAppearance="?android:attr/textAppearanceMedium" /> <TextView android:id="@+id/password_view" android:layout_height="wrap_content" android:layout_marginLeft="20dip" android:layout_marginRight="20dip" android:text="密码" android:textAppearance="?android:attr/textAppearanceMedium" android:layout_width="fill_parent"/> <EditText android:id="@+id/password_edit" android:layout_height="wrap_content" android:layout_width="fill_parent" android:layout_marginLeft="20dip" android:layout_marginRight="20dip" android:capitalize="none" android:password="true" android:textAppearance="?android:attr/textAppearanceMedium" /><LinearLayout android:id="@+id/LinearLayout01" android:layout_height="wrap_content" android:layout_width="fill_parent" android:gravity="center"><Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/BtnOK" android:layout_weight="100" android:text="确定"></Button><Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_weight="100" android:text="取消" android:id="@+id/BtnCancel"></Button></LinearLayout></LinearLayout>

接下来是Java程序源码：

package com.testAlertDialog;import android.app.Activity;import android.app.AlertDialog;import android.content.Context;import android.content.DialogInterface;import android.os.Bundle;import android.text.Editable;import android.view.Gravity;import android.view.LayoutInflater;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.EditText;import android.widget.PopupWindow;public class testAlertDialog extends Activity { Button btnPopupWindow; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); //定义按钮 btnPopupWindow=(Button)this.findViewById(R.id.Button01); btnPopupWindow.setOnClickListener(new ClickEvent()); } //统一处理按键事件 class ClickEvent implements OnClickListener{ @Override public void onClick(View v) { // TODO Auto-generated method stub if(v==btnPopupWindow) { showPopupWindow(testAlertDialog.this, testAlertDialog.this.findViewById(R.id.Button01)); } } } public void showPopupWindow(Context context,View parent){ LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); final View vPopupWindow=inflater.inflate(R.layout.popupwindow, null, false); final PopupWindow pw= new PopupWindow(vPopupWindow,300,300,true); //OK按钮及其处理事件 Button btnOK=(Button)vPopupWindow.findViewById(R.id.BtnOK); btnOK.setOnClickListener(new OnClickListener(){ @Override public void onClick(View v) { //设置文本框内容 EditText edtUsername=(EditText)vPopupWindow.findViewById(R.id.username_edit); edtUsername.setText("username"); EditText edtPassword=(EditText)vPopupWindow.findViewById(R.id.password_edit); edtPassword.setText("password"); } }); //Cancel按钮及其处理事件 Button btnCancel=(Button)vPopupWindow.findViewById(R.id.BtnCancel); btnCancel.setOnClickListener(new OnClickListener(){ @Override public void onClick(View v) { pw.dismiss();//关闭 } }); //显示popupWindow对话框 pw.showAtLocation(parent, Gravity.CENTER, 0, 0); }}