1、AlertDialog是一个信息提示框，当出现是，需要用户点击，才会消失
2、Toast也是一个信息提示框，出现后会更具设定的时间，自动消失
[代码] main.xml
01 <?xml version="1.0" encoding="utf-8"?>
02
03 <LinearLayout xmlns:Android="http://schemas.android.com/apk/res/android"
04Android:orientation="vertical"
05Android:layout_width="fill_parent"
06Android:layout_height="fill_parent"
07>
08 <ButtonAndroid:id="@+id/alert"
09Android:layout_width="fill_parent"
10Android:layout_height="wrap_content"
11Android:text="Make an alert"></Button>
12 <ButtonAndroid:id="@+id/toast"
13Android:layout_width="fill_parent"
14Android:layout_height="wrap_content"
15Android:text="Make a toast"></Button>
16 </LinearLayout>
[代码] MessageActivity.java
01 package yyl.message;
02
03 import Android.app.Activity;
04 import Android.app.AlertDialog;
05 import Android.content.DialogInterface;
06 import Android.os.Bundle;
07 import Android.view.View;
08 import Android.widget.Button;
09 import Android.widget.Toast;
10
11 public class MessageActivity extends Activity {
12//定义变量
13private Button alert = null;
14private Button toast = null;
15@Override
16public void onCreate(Bundle savedInstanceState) {
17super.onCreate(savedInstanceState);
18setContentView(R.layout.main);
19
20//根据Id得到控件对象
21alert = (Button)findViewById(R.id.alert);
22toast = (Button)findViewById(R.id.toast);
23
24//给按钮设定单击事件监听器
25alert.setOnClickListener(new View.OnClickListener() {
26
27@Override
28public void onClick(View v) {
29//显示AlertDialog
30newAlertDialog.Builder(MessageActivity.this).setTitle("MessageDemo").setMessage("Err").setNeutralButton("close",new DialogInterface.OnClickListener() {
31
32//点击AlertDialog上的按钮的事件处理代码
33@Override
34public void onClick(DialogInterface dialog, intwhich) {
35System.out.println("yangyulin");
36
37}
38}).show();
39
40}
41});
42toast.setOnClickListener(new View.OnClickListener() {
43
44//显示Toast
45@Override
46public void onClick(View v) {
47
48Toast.makeText(MessageActivity.this, "<Clink,Clink>", Toast.LENGTH_SHORT).show();
49
50}
51});
52}
53 }
