01.package com.android.tutor;
02.import android.app.Activity;
03.import android.content.Context;
04.import android.os.Bundle;
05.import android.view.Gravity;
06.import android.view.LayoutInflater;
07.import android.view.View;
08.import android.view.View.OnClickListener;
09.import android.view.ViewGroup.LayoutParams;
10.import android.widget.Button;
11.import android.widget.PopupWindow;
12.public class PopupWindowDemo extends Activity implements OnClickListener{
13. private Button btn;
14.
15. public void onCreate(Bundle savedInstanceState) {
16. super.onCreate(savedInstanceState);
17. setContentView(R.layout.main);
18.
19. btn = (Button)findViewById(R.id.btn);
20. btn.setOnClickListener(this);
21. }
22. @Override
23. public void onClick(View v) {
24. Context mContext = PopupWindowDemo.this;
25. if (v.getId() == R.id.btn) {
26. LayoutInflater mLayoutInflater = (LayoutInflater) mContext
27. .getSystemService(LAYOUT_INFLATER_SERVICE);
28. View music_popunwindwow = mLayoutInflater.inflate(
29. R.layout.music_popwindow, null);
30. PopupWindow mPopupWindow = new PopupWindow(music_popunwindwow, LayoutParams.FILL_PARENT,
31. LayoutParams.WRAP_CONTENT);
32.
33. mPopupWindow.showAtLocation(findViewById(R.id.main), Gravity.RIGHT|Gravity.BOTTOM, 0, 0);
34. }
35. }
36.}
需要强调的是这里PopupWindow必须有某个事件触发才会显示出来，不然总会抱错，不信大家可以试试!
随着这个问题的出现，就会同学问了，那么我想初始化让PopupWindow显示出来，那怎么办了，不去寄托于其他点击事件，
在这里我用了定时器Timer来实现这样的效果,当然这里就要用到Handler了
01.package com.android.tutor;
02.import java.util.Timer;
03.import java.util.TimerTask;
04.import android.app.Activity;
05.import android.content.Context;
06.import android.os.Bundle;
07.import android.os.Handler;
08.import android.os.Message;
09.import android.view.Gravity;
10.import android.view.LayoutInflater;
11.import android.view.View;
12.import android.view.ViewGroup.LayoutParams;
13.import android.widget.PopupWindow;
14.public class PopupWindowDemo extends Activity{
15. private Handler mHandler = new Handler(){
16.
17. public void handleMessage(Message msg) {
18. switch (msg.what) {
19. case 1:
20. showPopupWindow();
21. break;
22. }
23. };
24. };
25.
26. public void onCreate(Bundle savedInstanceState) {
27. super.onCreate(savedInstanceState);
28. setContentView(R.layout.main);
29.
30. //create the timer
31. Timer timer = new Timer();
32. timer.schedule(new initPopupWindow(), 100);
33. }
34.
35. private class initPopupWindow extends TimerTask{
36. @Override
37. public void run() {
38.
39. Message message = new Message();
40. message.what = 1;
41. mHandler.sendMessage(message);
42.
43. }
44. }
45.
46.
47. public void showPopupWindow() {
48. Context mContext = PopupWindowDemo.this;
49. LayoutInflater mLayoutInflater = (LayoutInflater) mContext
50. .getSystemService(LAYOUT_INFLATER_SERVICE);
51. View music_popunwindwow = mLayoutInflater.inflate(
52. R.layout.music_popwindow, null);
53. PopupWindow mPopupWindow = new PopupWindow(music_popunwindwow,
54. LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);
55. mPopupWindow.showAtLocation(findViewById(R.id.main), Gravity.CENTER, 0, 0);
56. }
57.}
main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/main"
android:orientation="vertical"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Welcome to Mr Wei's Blog!!"
/>
<Button
android:id="@+id/btn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Show PopupWindow"
/>
<Button
android:id="@+id/btn1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="hide PopupWindow"
/>
</LinearLayout>
本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/Android_Tutor/archive/2010/05/10/5576533.aspx