1 　　　　　var Event = {
 2             on: function (eventName, callback) {
 3                 console.log("eventName:"+eventName)
 4                 if (!this.handles) {
 5                     Object.defineProperty(this, "handles", {
 6                         value: {},
 7                         enumerable: false//不可枚举
 8                     })
 9                     //this.handles = {};//可以枚举
10                 }
11                 if (!this.handles[eventName]) {
12                     this.handles[eventName] = [];
13                 }
14                 this.handles[eventName].push(callback);
15             },
16             emit: function () {
17                 var hlist = this.handles[arguments[0]] || [];
18                 for (var i = 0; i < hlist.length; i++) {
19                     this.handles[arguments[0]][i](arguments[1]);
20                 }
21             }
22         }
23         Event.on("dome", function (params) {
24             console.log(params);
25         });
26         Event.on("dome", function (params) {
27             console.log("dome log");
28         });
29         Event.emit("dome", "holle world");
30
31         var person1 = {};
32         var person2 = {};
33         //Object.assign是浅复制，会导致person1，person2共用同一个handles
34         Object.assign(person1, Event);
35         Object.assign(person2, Event);
36         person1.on('call1', function () {
37             console.log('person1');
38         });
39         person2.on('call2', function () {
40             console.log('person2');
41         });
42         person1.emit('call1'); // 输出 'person1'
43         person1.emit('call2'); // 没有输出
44         person2.emit('call1'); // 没有输出
45         person2.emit('call2'); // 输出 'person2'