1.方式一：通过继承Event类编写Flex4的自定义事件
下面我们来做一个例子，实现这样的功能：监控TextInput的输入，通过监控输入的内容，触发不同的自定义事件。
我们先来写这个自定义事件：
ActionScript类Test43Event.as
1 package demo
2 {
3 import flash.events.Event;
4
5 public class Test43Event extends Event
6 {
7 public static var Test43_Number:String = "number";
8 public static var Test43_Letter:String = "letter";
9 public static var Test43_Other:String = "other";
10
11 public function Test43Event(type:String, bubbles:Boolean=false, cancelable:Boolean=false)
12 {
13 super(type, bubbles, cancelable);
14 }
15 }
16 }
然后添加一个MXML应用程序test43.mxml调用这个自定义事件
1 <?xml version="1.0" encoding="utf-8"?>
2 <s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
3 xmlns:s="library://ns.adobe.com/flex/spark"
4 xmlns:mx="library://ns.adobe.com/flex/mx" minWidth="955" minHeight="600" creationComplete="application1_creationCompleteHandler(event)">
5 <s:layout>
6 <s:BasicLayout/>
7 </s:layout>
8
9 <fx:Script>
10 <![CDATA[
11 import mx.events.FlexEvent;
12 protected function textinput1_keyDownHandler(event:KeyboardEvent):void
13 {
14 var test43Event:Test43Event;
15 if(event.keyCode>=48 && event.keyCode<=57) //0-9
16 {
17 test43Event = new Test43Event(Test43Event.Test43_Number);
18 dispatchEvent(test43Event);
19 }
20 else if(event.keyCode>=65 && event.keyCode<=90) //a-z A-Z
21 {
22 test43Event = new Test43Event(Test43Event.Test43_Letter);
23 dispatchEvent(test43Event);
24 }
25 else
26 {
27 test43Event = new Test43Event(Test43Event.Test43_Other);
28 dispatchEvent(test43Event);
29 }
30 }
31
32 private function func1(event:Event):void
33 {
34 if(event.type==Test43Event.Test43_Letter)
35 {
36 msg.text = "当前输入的是字母";
37 }
38 else if(event.type==Test43Event.Test43_Number)
39 {
40 msg.text = "当前输入的是数字";
41 }
42 else if(event.type==Test43Event.Test43_Other)
43 {
44 msg.text = "当前输入的是其他字符";
45 }
46 }
47
48 protected function application1_creationCompleteHandler(event:FlexEvent):void
49 {
50 this.addEventListener(Test43Event.Test43_Letter,func1);
51 this.addEventListener(Test43Event.Test43_Number,func1);
52 this.addEventListener(Test43Event.Test43_Other,func1);
53 }
54
55 ]]>
56 </fx:Script>
57
58 <fx:Declarations>
59 <!-- 将非可视元素（例如服务、值对象）放在此处 -->
60 </fx:Declarations>
61 <s:TextInput id="text1" x="140" y="157" keyDown="textinput1_keyDownHandler(event)"/>
62 <s:Label id="msg" x="140" y="128"/>
63 </s:Application>
2.方式二：直接使用dispatchEvent编写Flex4的自定义事件
1 <?xml version="1.0" encoding="utf-8"?>
2 <s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
3 xmlns:s="library://ns.adobe.com/flex/spark"
4 xmlns:mx="library://ns.adobe.com/flex/mx" minWidth="955" minHeight="600" creationComplete="application1_creationCompleteHandler(event)">
5 <s:layout>
6 <s:BasicLayout/>
7 </s:layout>
8 <fx:Script>
9 <![CDATA[
10 import mx.events.FlexEvent;
11
12 protected function application1_creationCompleteHandler(event:FlexEvent):void
13 {
14
15 this.addEventListener("Letter",func1);
16 this.addEventListener("Other",func1);
17 }
18
19 private function func1(event:Event):void
20 {
21 if(event.type == "Letter")
22 {
23 msg.text = "当前选择的是字母";
24 }
25 else
26 {
27 msg.text = "当前选择的不是字母";
28 }
29 }
30
31
32 protected function textinput1_keyDownHandler(event:KeyboardEvent):void
33 {
34 if(event.keyCode>=65 && event.keyCode<=90) //a-z A-Z
35 {
36 dispatchEvent(new Event("Letter"));
37 }
38 else
39 {
40 dispatchEvent(new Event("Other"));
41 }
42 }
43
44 ]]>
45 </fx:Script>
46 <fx:Declarations>
47 <!-- 将非可视元素（例如服务、值对象）放在此处 -->
48 </fx:Declarations>
49 <s:TextInput x="180" y="179" keyDown="textinput1_keyDownHandler(event)"/>
50 <s:Label x="179" y="143" id="msg"/>
51 </s:Application>
