nodejs -- event 模块, 事件模块.

时间：2017-08-04 12:43:40 阅读：211 评论：0 收藏：0 [点我收藏+]

1. 注册事件 on 或者 addListener,触发事件 emit

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1-1简单的使用:

 1 var EventEmitter =  require(‘events‘).EventEmitter;
 2 
 3 var life = new EventEmitter();
 4 
 5 //求安慰:
 6 
 7 
 8 function water(who){
 9     console.log(‘给 ‘ +who+ ‘ 倒水‘);
10 }
11 //具名函数
12 life.addListener(‘求安慰‘, water);
13 
14 //匿名函数
15 life.addListener(‘求安慰‘, function(who){
16     console.log(‘给 ‘ +who+ ‘ 揉肩‘);
17 });
18 
19 
20 function cook(who){
21     console.log(‘给 ‘ +who+ ‘ 做饭‘);
22 }
23 //具名函数
24 life.on(‘求安慰‘, cook);
25 //匿名函数
26 life.on(‘求安慰‘, function(who){
27     console.log(‘给 ‘ +who+ ‘ 洗衣服‘);
28 });
29 
30 life.on(‘求安慰‘, function(who){
31     console.log(‘给 ‘ +who+ ‘ .....5‘);
32 });
33 
34 life.on(‘求安慰‘, function(who){
35     console.log(‘给 ‘ +who+ ‘ .....6‘);
36 });
37 
38 life.on(‘求安慰‘, function(who){
39     console.log(‘给 ‘ +who+ ‘ .....7‘);
40 });
41 
42 life.on(‘求安慰‘, function(who){
43     console.log(‘给 ‘ +who+ ‘ .....8‘);
44 });
45 
46 life.on(‘求安慰‘, function(who){
47     console.log(‘给 ‘ +who+ ‘ .....9‘);
48 });
49 
50 
51 //求溺爱
52 
53 life.on(‘求溺爱‘, function(who){
54     console.log(‘给 ‘ +who+ ‘ 买包包1‘);
55 });
56 
57 life.on(‘求溺爱‘, function(who){
58     console.log(‘给 ‘ +who+ ‘ 看电影1‘);
59 });
60 
61 life.on(‘求溺爱‘, function(who){
62     console.log(‘给 ‘ +who+ ‘ 去旅游1‘);
63 });
64 
65 //触发:
66 life.emit(‘求安慰‘, ‘汉子‘);

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这里一共有两个事件, 求安慰, 一共有 9个动作; 求溺爱 ,一共有 3个动作
添加事件监听有 addListener() 和 on() 两种方法, 这两种方法都可以使用具名函数和匿名函数.
emit() 触发事件, 上面没有触发 [求溺爱]事件, 因此没有输出.

---------------------------------------

触发 [求溺爱] 事件.

1 //触发:
2 life.emit(‘求安慰‘, ‘汉子‘);
3 
4 life.emit(‘求溺爱‘, ‘妹子‘);

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-----------------------------------------------------------------------

1-2emit(event, 参数1, 参数2,参数3) 传递多个参数的时候:

 1 var EventEmitter =  require(‘events‘).EventEmitter;
 2 
 3 var life = new EventEmitter();
 4 
 5 
 6 
 7 //求安慰:
 8 
 9 
10 function water(who){
11     console.log(‘给 ‘ +who+ ‘ 倒水1‘);
12 }
13 //具名函数
14 life.addListener(‘求安慰‘, water);
15 
16 //匿名函数
17 life.addListener(‘求安慰‘, function(who){
18     console.log(‘给 ‘ +who+ ‘ 揉肩2‘);
19 });
20 
21 
22 function cook(who){
23     console.log(‘给 ‘ +who+ ‘ 做饭3‘);
24 }
25 //具名函数
26 life.on(‘求安慰‘, cook);
27 //匿名函数
28 life.on(‘求安慰‘, function(who){
29     console.log(‘给 ‘ +who+ ‘ 洗衣服4‘);
30 });
31 
32 life.on(‘求安慰‘, function(){
33     console.log(‘这个是 第 5个 监听器‘);
34 });
35 
36 life.on(‘求安慰‘, function(address, age){
37     console.log(‘我要去‘ +address+ ‘旅游,我的年龄是‘ +age );
38 });
39 
40 
41 
42 
43 
44 //触发:
45 life.emit(‘求安慰‘, ‘汉子‘, ‘北京‘, 26);

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红色部分显然是不符合我们的要求的.

---

解决办法: 使得 36行是 3个参数, 但是第一个参数不使用 .

 1 var EventEmitter =  require(‘events‘).EventEmitter;
 2 
 3 var life = new EventEmitter();
 4 
 5 
 6 
 7 //求安慰:
 8 
 9 
10 function water(who){
11     console.log(‘给 ‘ +who+ ‘ 倒水1‘);
12 }
13 //具名函数
14 life.addListener(‘求安慰‘, water);
15 
16 //匿名函数
17 life.addListener(‘求安慰‘, function(who){
18     console.log(‘给 ‘ +who+ ‘ 揉肩2‘);
19 });
20 
21 
22 function cook(who){
23     console.log(‘给 ‘ +who+ ‘ 做饭3‘);
24 }
25 //具名函数
26 life.on(‘求安慰‘, cook);
27 //匿名函数
28 life.on(‘求安慰‘, function(who){
29     console.log(‘给 ‘ +who+ ‘ 洗衣服4‘);
30 });
31 
32 life.on(‘求安慰‘, function(){
33     console.log(‘这个是 第 5个 监听器‘);
34 });
35 
36 life.on(‘求安慰‘, function(who, address, age){
37     console.log(‘我要去‘ +address+ ‘旅游,我的年龄是‘ +age );
38 });
39 
40 
41 
42 
43 
44 //触发:
45 life.emit(‘求安慰‘, ‘汉子‘, ‘北京‘, 26);

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1-3:如何判断事件有没有注册监听器?

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 1 var EventEmitter =  require(‘events‘).EventEmitter;
 2 
 3 var life = new EventEmitter();
 4 
 5 
 6 
 7 //求安慰:
 8 
 9 
10 function water(who){
11     console.log(‘给 ‘ +who+ ‘ 倒水1‘);
12 }
13 //具名函数
14 life.addListener(‘求安慰‘, water);
15 
16 //匿名函数
17 life.addListener(‘求安慰‘, function(who){
18     console.log(‘给 ‘ +who+ ‘ 揉肩2‘);
19 });
20 
21 
22 function cook(who){
23     console.log(‘给 ‘ +who+ ‘ 做饭3‘);
24 }
25 //具名函数
26 life.on(‘求安慰‘, cook);
27 //匿名函数
28 life.on(‘求安慰‘, function(who){
29     console.log(‘给 ‘ +who+ ‘ 洗衣服4‘);
30 });
31 
32 life.on(‘求安慰‘, function(){
33     console.log(‘这个是 第 5个 监听器‘);
34 });
35 
36 life.on(‘求安慰‘, function(who, address, age){
37     console.log(‘我要去‘ +address+ ‘旅游,我的年龄是‘ +age );
38 });
39 
40 
41 
42 
43 
44 //触发:
45 var anwei = life.emit(‘求安慰‘, ‘汉子‘, ‘北京‘, 26);
46 
47 var niai = life.emit(‘求溺爱‘);
48 
49 console.log(anwei);
50 console.log(niai);

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可见 , [求安慰] 事件注册了监听器, [求溺爱]事件没有注册监听器.

2. 设置事件可以拥有的监听器数量.setMaxListeners(n)

默认是10个:

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 1 var EventEmitter =  require(‘events‘).EventEmitter;
 2 
 3 var life = new EventEmitter();
 4 
 5 //求安慰:
 6 
 7 
 8 function water(who){
 9     console.log(‘给 ‘ +who+ ‘ 倒水‘);
10 }
11 //具名函数
12 life.addListener(‘求安慰‘, water);
13 
14 //匿名函数
15 life.addListener(‘求安慰‘, function(who){
16     console.log(‘给 ‘ +who+ ‘ 揉肩‘);
17 });
18 
19 
20 function cook(who){
21     console.log(‘给 ‘ +who+ ‘ 做饭‘);
22 }
23 //具名函数
24 life.on(‘求安慰‘, cook);
25 //匿名函数
26 life.on(‘求安慰‘, function(who){
27     console.log(‘给 ‘ +who+ ‘ 洗衣服‘);
28 });
29 
30 life.on(‘求安慰‘, function(who){
31     console.log(‘给 ‘ +who+ ‘ .....5‘);
32 });
33 
34 life.on(‘求安慰‘, function(who){
35     console.log(‘给 ‘ +who+ ‘ .....6‘);
36 });
37 
38 life.on(‘求安慰‘, function(who){
39     console.log(‘给 ‘ +who+ ‘ .....7‘);
40 });
41 
42 life.on(‘求安慰‘, function(who){
43     console.log(‘给 ‘ +who+ ‘ .....8‘);
44 });
45 
46 life.on(‘求安慰‘, function(who){
47     console.log(‘给 ‘ +who+ ‘ .....9‘);
48 });
49 
50 life.on(‘求安慰‘, function(who){
51     console.log(‘给 ‘ +who+ ‘ .....10‘);
52 });
53 
54 life.on(‘求安慰‘, function(who){
55     console.log(‘给 ‘ +who+ ‘ .....11‘);
56 });
57 
58 
59 //求溺爱
60 
61 life.on(‘求溺爱‘, function(who){
62     console.log(‘给 ‘ +who+ ‘ 买包包1‘);
63 });
64 
65 life.on(‘求溺爱‘, function(who){
66     console.log(‘给 ‘ +who+ ‘ 看电影1‘);
67 });
68 
69 life.on(‘求溺爱‘, function(who){
70     console.log(‘给 ‘ +who+ ‘ 去旅游1‘);
71 });
72 
73 //触发:
74 life.emit(‘求安慰‘, ‘汉子‘);
75 
76 life.emit(‘求溺爱‘, ‘妹子‘);

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--------------------------------------

增加事件的最大监听器数量为 11.

  1 var EventEmitter =  require(‘events‘).EventEmitter;
  2 
  3 var life = new EventEmitter();
  4 
  5 // 设置事件 允许  的 最多 监听器 的数量
  6 life.setMaxListeners(11);
  7 
  8 //求安慰:
  9 
 10 
 11 function water(who){
 12     console.log(‘给 ‘ +who+ ‘ 倒水‘);
 13 }
 14 //具名函数
 15 life.addListener(‘求安慰‘, water);
 16 
 17 //匿名函数
 18 life.addListener(‘求安慰‘, function(who){
 19     console.log(‘给 ‘ +who+ ‘ 揉肩‘);
 20 });
 21 
 22 
 23 function cook(who){
 24     console.log(‘给 ‘ +who+ ‘ 做饭‘);
 25 }
 26 //具名函数
 27 life.on(‘求安慰‘, cook);
 28 //匿名函数
 29 life.on(‘求安慰‘, function(who){
 30     console.log(‘给 ‘ +who+ ‘ 洗衣服‘);
 31 });
 32 
 33 life.on(‘求安慰‘, function(who){
 34     console.log(‘给 ‘ +who+ ‘ .....5‘);
 35 });
 36 
 37 life.on(‘求安慰‘, function(who){
 38     console.log(‘给 ‘ +who+ ‘ .....6‘);
 39 });
 40 
 41 life.on(‘求安慰‘, function(who){
 42     console.log(‘给 ‘ +who+ ‘ .....7‘);
 43 });
 44 
 45 life.on(‘求安慰‘, function(who){
 46     console.log(‘给 ‘ +who+ ‘ .....8‘);
 47 });
 48 
 49 life.on(‘求安慰‘, function(who){
 50     console.log(‘给 ‘ +who+ ‘ .....9‘);
 51 });
 52 
 53 life.on(‘求安慰‘, function(who){
 54     console.log(‘给 ‘ +who+ ‘ .....10‘);
 55 });
 56 
 57 life.on(‘求安慰‘, function(who){
 58     console.log(‘给 ‘ +who+ ‘ .....11‘);
 59 });
 60 
 61 
 62 //求溺爱
 63 
 64 life.on(‘求溺爱‘, function(who){
 65     console.log(‘给 ‘ +who+ ‘ 买包包1‘);
 66 });
 67 
 68 life.on(‘求溺爱‘, function(who){
 69     console.log(‘给 ‘ +who+ ‘ 看电影2‘);
 70 });
 71 
 72 life.on(‘求溺爱‘, function(who){
 73     console.log(‘给 ‘ +who+ ‘ 去旅游3‘);
 74 });
 75 
 76 life.on(‘求溺爱‘, function(who){
 77     console.log(‘给 ‘ +who+ ‘ .....4‘);
 78 });
 79 
 80 life.on(‘求溺爱‘, function(who){
 81     console.log(‘给 ‘ +who+ ‘ .....5‘);
 82 });
 83 
 84 life.on(‘求溺爱‘, function(who){
 85     console.log(‘给 ‘ +who+ ‘ .....6‘);
 86 });
 87 
 88 life.on(‘求溺爱‘, function(who){
 89     console.log(‘给 ‘ +who+ ‘ .....7‘);
 90 });
 91 
 92 life.on(‘求溺爱‘, function(who){
 93     console.log(‘给 ‘ +who+ ‘ .....8‘);
 94 });
 95 
 96 
 97 life.on(‘求溺爱‘, function(who){
 98     console.log(‘给 ‘ +who+ ‘ .....9‘);
 99 });
100 
101 
102 life.on(‘求溺爱‘, function(who){
103     console.log(‘给 ‘ +who+ ‘ .....10‘);
104 });
105 
106 
107 life.on(‘求溺爱‘, function(who){
108     console.log(‘给 ‘ +who+ ‘ .....11‘);
109 });
110 
111 
112 
113 
114 //触发:
115 life.emit(‘求安慰‘, ‘汉子‘);
116 
117 life.emit(‘求溺爱‘, ‘妹子‘);

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注意:

　　life.setMaxListeners(11); 在添加事件之前设置允许的事件监听器数量是 11个.
添加的事件监听器数量是针对所有的事件生效的; 本脚本内, 有两个事件, [求安慰] [求溺爱] 都有了 11个监听器.

3. 移除单个: 移除某个事件的某一个监听器. removeListener(event, listener)

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  1 var EventEmitter =  require(‘events‘).EventEmitter;
  2 
  3 var life = new EventEmitter();
  4 
  5 // 设置事件 允许  的 最多 监听器 的数量
  6 life.setMaxListeners(11);
  7 
  8 //求安慰:
  9 
 10 
 11 function water(who){
 12     console.log(‘给 ‘ +who+ ‘ 倒水‘);
 13 }
 14 //具名函数
 15 life.addListener(‘求安慰‘, water);
 16 
 17 //匿名函数
 18 life.addListener(‘求安慰‘, function(who){
 19     console.log(‘给 ‘ +who+ ‘ 揉肩‘);
 20 });
 21 
 22 
 23 function cook(who){
 24     console.log(‘给 ‘ +who+ ‘ 做饭‘);
 25 }
 26 //具名函数
 27 life.on(‘求安慰‘, cook);
 28 //匿名函数
 29 life.on(‘求安慰‘, function(who){
 30     console.log(‘给 ‘ +who+ ‘ 洗衣服‘);
 31 });
 32 
 33 life.on(‘求安慰‘, function(who){
 34     console.log(‘给 ‘ +who+ ‘ .....5‘);
 35 });
 36 
 37 life.on(‘求安慰‘, function(who){
 38     console.log(‘给 ‘ +who+ ‘ .....6‘);
 39 });
 40 
 41 life.on(‘求安慰‘, function(who){
 42     console.log(‘给 ‘ +who+ ‘ .....7‘);
 43 });
 44 
 45 life.on(‘求安慰‘, function(who){
 46     console.log(‘给 ‘ +who+ ‘ .....8‘);
 47 });
 48 
 49 life.on(‘求安慰‘, function(who){
 50     console.log(‘给 ‘ +who+ ‘ .....9‘);
 51 });
 52 
 53 life.on(‘求安慰‘, function(who){
 54     console.log(‘给 ‘ +who+ ‘ .....10‘);
 55 });
 56 
 57 life.on(‘求安慰‘, function(who){
 58     console.log(‘给 ‘ +who+ ‘ .....11‘);
 59 });
 60 
 61 
 62 //求溺爱
 63 
 64 life.on(‘求溺爱‘, function(who){
 65     console.log(‘给 ‘ +who+ ‘ 买包包1‘);
 66 });
 67 
 68 life.on(‘求溺爱‘, function(who){
 69     console.log(‘给 ‘ +who+ ‘ 看电影2‘);
 70 });
 71 
 72 life.on(‘求溺爱‘, function(who){
 73     console.log(‘给 ‘ +who+ ‘ 去旅游3‘);
 74 });
 75 
 76 life.on(‘求溺爱‘, function(who){
 77     console.log(‘给 ‘ +who+ ‘ .....4‘);
 78 });
 79 
 80 life.on(‘求溺爱‘, function(who){
 81     console.log(‘给 ‘ +who+ ‘ .....5‘);
 82 });
 83 
 84 life.on(‘求溺爱‘, function(who){
 85     console.log(‘给 ‘ +who+ ‘ .....6‘);
 86 });
 87 
 88 life.on(‘求溺爱‘, function(who){
 89     console.log(‘给 ‘ +who+ ‘ .....7‘);
 90 });
 91 
 92 life.on(‘求溺爱‘, function(who){
 93     console.log(‘给 ‘ +who+ ‘ .....8‘);
 94 });
 95 
 96 
 97 life.on(‘求溺爱‘, function(who){
 98     console.log(‘给 ‘ +who+ ‘ .....9‘);
 99 });
100 
101 
102 life.on(‘求溺爱‘, function(who){
103     console.log(‘给 ‘ +who+ ‘ .....10‘);
104 });
105 
106 
107 life.on(‘求溺爱‘, function(who){
108     console.log(‘给 ‘ +who+ ‘ .....11‘);
109 });
110 
111 
112 life.removeListener(‘求安慰‘, water);
113 
114 //触发:
115 life.emit(‘求安慰‘, ‘汉子‘);
116 
117 life.emit(‘求溺爱‘, ‘妹子‘);

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注意:

上面移除了 water 对应的 [倒水]事件.
这个函数只能移除单个事件的某个监听器
1. 不可以移除所有的事件的监听器
2. 不可以移除单个事件的所有监听器, removeListen(‘求安慰‘) , 这种用法会报错
这个函数只能移除具名函数对应的监听器 ; 匿名函数注册的监听器无法移除.

4. 判断事件拥有的监听器的数量 listeners(event) , listenerCount(emitter, event)

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  1 var EventEmitter =  require(‘events‘).EventEmitter;
  2 
  3 var life = new EventEmitter();
  4 
  5 // 设置事件 允许  的 最多 监听器 的数量
  6 life.setMaxListeners(11);
  7 
  8 //求安慰:
  9 
 10 
 11 function water(who){
 12     console.log(‘给 ‘ +who+ ‘ 倒水‘);
 13 }
 14 //具名函数
 15 life.addListener(‘求安慰‘, water);
 16 
 17 //匿名函数
 18 life.addListener(‘求安慰‘, function(who){
 19     console.log(‘给 ‘ +who+ ‘ 揉肩‘);
 20 });
 21 
 22 
 23 function cook(who){
 24     console.log(‘给 ‘ +who+ ‘ 做饭‘);
 25 }
 26 //具名函数
 27 life.on(‘求安慰‘, cook);
 28 //匿名函数
 29 life.on(‘求安慰‘, function(who){
 30     console.log(‘给 ‘ +who+ ‘ 洗衣服‘);
 31 });
 32 
 33 life.on(‘求安慰‘, function(who){
 34     console.log(‘给 ‘ +who+ ‘ .....5‘);
 35 });
 36 
 37 life.on(‘求安慰‘, function(who){
 38     console.log(‘给 ‘ +who+ ‘ .....6‘);
 39 });
 40 
 41 life.on(‘求安慰‘, function(who){
 42     console.log(‘给 ‘ +who+ ‘ .....7‘);
 43 });
 44 
 45 life.on(‘求安慰‘, function(who){
 46     console.log(‘给 ‘ +who+ ‘ .....8‘);
 47 });
 48 
 49 life.on(‘求安慰‘, function(who){
 50     console.log(‘给 ‘ +who+ ‘ .....9‘);
 51 });
 52 
 53 life.on(‘求安慰‘, function(who){
 54     console.log(‘给 ‘ +who+ ‘ .....10‘);
 55 });
 56 
 57 life.on(‘求安慰‘, function(who){
 58     console.log(‘给 ‘ +who+ ‘ .....11‘);
 59 });
 60 
 61 
 62 //求溺爱
 63 
 64 life.on(‘求溺爱‘, function(who){
 65     console.log(‘给 ‘ +who+ ‘ 买包包1‘);
 66 });
 67 
 68 life.on(‘求溺爱‘, function(who){
 69     console.log(‘给 ‘ +who+ ‘ 看电影2‘);
 70 });
 71 
 72 life.on(‘求溺爱‘, function(who){
 73     console.log(‘给 ‘ +who+ ‘ 去旅游3‘);
 74 });
 75 
 76 life.on(‘求溺爱‘, function(who){
 77     console.log(‘给 ‘ +who+ ‘ .....4‘);
 78 });
 79 
 80 life.on(‘求溺爱‘, function(who){
 81     console.log(‘给 ‘ +who+ ‘ .....5‘);
 82 });
 83 
 84 life.on(‘求溺爱‘, function(who){
 85     console.log(‘给 ‘ +who+ ‘ .....6‘);
 86 });
 87 
 88 life.on(‘求溺爱‘, function(who){
 89     console.log(‘给 ‘ +who+ ‘ .....7‘);
 90 });
 91 
 92 life.on(‘求溺爱‘, function(who){
 93     console.log(‘给 ‘ +who+ ‘ .....8‘);
 94 });
 95 
 96 
 97 life.on(‘求溺爱‘, function(who){
 98     console.log(‘给 ‘ +who+ ‘ .....9‘);
 99 });
100 
101 
102 life.on(‘求溺爱‘, function(who){
103     console.log(‘给 ‘ +who+ ‘ .....10‘);
104 });
105 
106 
107 life.on(‘求溺爱‘, function(who){
108     console.log(‘给 ‘ +who+ ‘ .....11‘);
109 });
110 
111 console.log(‘移除前:‘);
112 console.log(life.listeners().length);
113 console.log(life.listeners(‘求安慰‘).length);
114 
115 console.log(EventEmitter.listenerCount(life, ‘求安慰‘));
116 
117 life.removeListener(‘求安慰‘, water);
118 
119 console.log(‘移除后:‘);
120 console.log(life.listeners().length);
121 console.log(life.listeners(‘求安慰‘).length);
122 
123 console.log(EventEmitter.listenerCount(life, ‘求安慰‘));
124 
125 //触发:
126 // life.emit(‘求安慰‘, ‘汉子‘);
127 
128 // life.emit(‘求溺爱‘, ‘妹子‘);

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注意:

EventEmitter类的实例.listeners(事件名).length 和 EventEmitter.listenerCount(实例名, 事件名) 都可以获得对应的实例中的对应的事件绑定的监听器数量
EventEmitter类的实例.listeners().length , 如果没有传递事件名 , 数量就是0 ; 可见必须传递事件名
移除water之前 , [求安慰] 的监听器是 11个 , 移除water之后, [求安慰] 的监听器数量是 10个.

5. 批量移除某个实例中的事件绑定的监听器 : removeAllListeners([event])

技术分享

5-1: 批量移除某个实例中的某个事件的所有监听器:

  1 var EventEmitter =  require(‘events‘).EventEmitter;
  2 
  3 var life = new EventEmitter();
  4 
  5 // 设置事件 允许  的 最多 监听器 的数量
  6 life.setMaxListeners(11);
  7 
  8 //求安慰:
  9 
 10 
 11 function water(who){
 12     console.log(‘给 ‘ +who+ ‘ 倒水‘);
 13 }
 14 //具名函数
 15 life.addListener(‘求安慰‘, water);
 16 
 17 //匿名函数
 18 life.addListener(‘求安慰‘, function(who){
 19     console.log(‘给 ‘ +who+ ‘ 揉肩‘);
 20 });
 21 
 22 
 23 function cook(who){
 24     console.log(‘给 ‘ +who+ ‘ 做饭‘);
 25 }
 26 //具名函数
 27 life.on(‘求安慰‘, cook);
 28 //匿名函数
 29 life.on(‘求安慰‘, function(who){
 30     console.log(‘给 ‘ +who+ ‘ 洗衣服‘);
 31 });
 32 
 33 life.on(‘求安慰‘, function(who){
 34     console.log(‘给 ‘ +who+ ‘ .....5‘);
 35 });
 36 
 37 life.on(‘求安慰‘, function(who){
 38     console.log(‘给 ‘ +who+ ‘ .....6‘);
 39 });
 40 
 41 life.on(‘求安慰‘, function(who){
 42     console.log(‘给 ‘ +who+ ‘ .....7‘);
 43 });
 44 
 45 life.on(‘求安慰‘, function(who){
 46     console.log(‘给 ‘ +who+ ‘ .....8‘);
 47 });
 48 
 49 life.on(‘求安慰‘, function(who){
 50     console.log(‘给 ‘ +who+ ‘ .....9‘);
 51 });
 52 
 53 life.on(‘求安慰‘, function(who){
 54     console.log(‘给 ‘ +who+ ‘ .....10‘);
 55 });
 56 
 57 life.on(‘求安慰‘, function(who){
 58     console.log(‘给 ‘ +who+ ‘ .....11‘);
 59 });
 60 
 61 
 62 //求溺爱
 63 
 64 life.on(‘求溺爱‘, function(who){
 65     console.log(‘给 ‘ +who+ ‘ 买包包1‘);
 66 });
 67 
 68 life.on(‘求溺爱‘, function(who){
 69     console.log(‘给 ‘ +who+ ‘ 看电影2‘);
 70 });
 71 
 72 life.on(‘求溺爱‘, function(who){
 73     console.log(‘给 ‘ +who+ ‘ 去旅游3‘);
 74 });
 75 
 76 life.on(‘求溺爱‘, function(who){
 77     console.log(‘给 ‘ +who+ ‘ .....4‘);
 78 });
 79 
 80 life.on(‘求溺爱‘, function(who){
 81     console.log(‘给 ‘ +who+ ‘ .....5‘);
 82 });
 83 
 84 life.on(‘求溺爱‘, function(who){
 85     console.log(‘给 ‘ +who+ ‘ .....6‘);
 86 });
 87 
 88 life.on(‘求溺爱‘, function(who){
 89     console.log(‘给 ‘ +who+ ‘ .....7‘);
 90 });
 91 
 92 life.on(‘求溺爱‘, function(who){
 93     console.log(‘给 ‘ +who+ ‘ .....8‘);
 94 });
 95 
 96 
 97 life.on(‘求溺爱‘, function(who){
 98     console.log(‘给 ‘ +who+ ‘ .....9‘);
 99 });
100 
101 
102 life.on(‘求溺爱‘, function(who){
103     console.log(‘给 ‘ +who+ ‘ .....10‘);
104 });
105 
106 
107 life.on(‘求溺爱‘, function(who){
108     console.log(‘给 ‘ +who+ ‘ .....11‘);
109 });
110 
111 life.removeAllListeners(‘求安慰‘);
112 
113 
114 //触发:
115 var anwei = life.emit(‘求安慰‘, ‘汉子‘);
116 var niai = life.emit(‘求溺爱‘, ‘妹子‘);
117 
118 console.log(anwei);
119 console.log(niai);

技术分享

可见 [求安慰] 没有注册事件.

5-2: 批量移除某个实例中的所有事件的监听器:

  1 var EventEmitter =  require(‘events‘).EventEmitter;
  2 
  3 var life = new EventEmitter();
  4 
  5 // 设置事件 允许  的 最多 监听器 的数量
  6 life.setMaxListeners(11);
  7 
  8 //求安慰:
  9 
 10 
 11 function water(who){
 12     console.log(‘给 ‘ +who+ ‘ 倒水‘);
 13 }
 14 //具名函数
 15 life.addListener(‘求安慰‘, water);
 16 
 17 //匿名函数
 18 life.addListener(‘求安慰‘, function(who){
 19     console.log(‘给 ‘ +who+ ‘ 揉肩‘);
 20 });
 21 
 22 
 23 function cook(who){
 24     console.log(‘给 ‘ +who+ ‘ 做饭‘);
 25 }
 26 //具名函数
 27 life.on(‘求安慰‘, cook);
 28 //匿名函数
 29 life.on(‘求安慰‘, function(who){
 30     console.log(‘给 ‘ +who+ ‘ 洗衣服‘);
 31 });
 32 
 33 life.on(‘求安慰‘, function(who){
 34     console.log(‘给 ‘ +who+ ‘ .....5‘);
 35 });
 36 
 37 life.on(‘求安慰‘, function(who){
 38     console.log(‘给 ‘ +who+ ‘ .....6‘);
 39 });
 40 
 41 life.on(‘求安慰‘, function(who){
 42     console.log(‘给 ‘ +who+ ‘ .....7‘);
 43 });
 44 
 45 life.on(‘求安慰‘, function(who){
 46     console.log(‘给 ‘ +who+ ‘ .....8‘);
 47 });
 48 
 49 life.on(‘求安慰‘, function(who){
 50     console.log(‘给 ‘ +who+ ‘ .....9‘);
 51 });
 52 
 53 life.on(‘求安慰‘, function(who){
 54     console.log(‘给 ‘ +who+ ‘ .....10‘);
 55 });
 56 
 57 life.on(‘求安慰‘, function(who){
 58     console.log(‘给 ‘ +who+ ‘ .....11‘);
 59 });
 60 
 61 
 62 //求溺爱
 63 
 64 life.on(‘求溺爱‘, function(who){
 65     console.log(‘给 ‘ +who+ ‘ 买包包1‘);
 66 });
 67 
 68 life.on(‘求溺爱‘, function(who){
 69     console.log(‘给 ‘ +who+ ‘ 看电影2‘);
 70 });
 71 
 72 life.on(‘求溺爱‘, function(who){
 73     console.log(‘给 ‘ +who+ ‘ 去旅游3‘);
 74 });
 75 
 76 life.on(‘求溺爱‘, function(who){
 77     console.log(‘给 ‘ +who+ ‘ .....4‘);
 78 });
 79 
 80 life.on(‘求溺爱‘, function(who){
 81     console.log(‘给 ‘ +who+ ‘ .....5‘);
 82 });
 83 
 84 life.on(‘求溺爱‘, function(who){
 85     console.log(‘给 ‘ +who+ ‘ .....6‘);
 86 });
 87 
 88 life.on(‘求溺爱‘, function(who){
 89     console.log(‘给 ‘ +who+ ‘ .....7‘);
 90 });
 91 
 92 life.on(‘求溺爱‘, function(who){
 93     console.log(‘给 ‘ +who+ ‘ .....8‘);
 94 });
 95 
 96 
 97 life.on(‘求溺爱‘, function(who){
 98     console.log(‘给 ‘ +who+ ‘ .....9‘);
 99 });
100 
101 
102 life.on(‘求溺爱‘, function(who){
103     console.log(‘给 ‘ +who+ ‘ .....10‘);
104 });
105 
106 
107 life.on(‘求溺爱‘, function(who){
108     console.log(‘给 ‘ +who+ ‘ .....11‘);
109 });
110 
111 // life.removeAllListeners(‘求安慰‘);
112 life.removeAllListeners();
113 
114 
115 //触发:
116 var anwei = life.emit(‘求安慰‘, ‘汉子‘);
117 var niai = life.emit(‘求溺爱‘, ‘妹子‘);
118 
119 console.log(anwei);
120 console.log(niai);

技术分享

可见 , [求安慰],[求溺爱] 都没有监听器.

参考链接:

nodejs -- event 模块, 事件模块.

标签：红色 logs 参数 eve 事件监听器批量用法输出可见

原文地址：http://www.cnblogs.com/cbza/p/7284364.html

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周排行

nodejs -- event 模块, 事件模块.

1. 注册事件 on 或者 addListener,触发事件 emit

1-1简单的使用:

1-2emit(event, 参数1, 参数2,参数3) 传递多个参数的时候:

1-3:如何判断 事件有没有注册 监听器?

2. 设置事件 可以拥有的监听器数量.setMaxListeners(n)

3. 移除单个: 移除某个事件 的 某一个监听器. removeListener(event, listener)

4. 判断 事件拥有的 监听器 的数量 listeners(event) , listenerCount(emitter, event)

5. 批量移除 某个实例中的事件绑定 的 监听器 : removeAllListeners([event])

5-1: 批量移除 某个实例 中的 某个事件 的所有 监听器:

5-2: 批量移除 某个实例 中 的所有事件 的 监听器:

参考链接:

1-3:如何判断事件有没有注册监听器?

2. 设置事件可以拥有的监听器数量.setMaxListeners(n)

3. 移除单个: 移除某个事件的某一个监听器. removeListener(event, listener)

4. 判断事件拥有的监听器的数量 listeners(event) , listenerCount(emitter, event)

5. 批量移除某个实例中的事件绑定的监听器 : removeAllListeners([event])

5-1: 批量移除某个实例中的某个事件的所有监听器:

5-2: 批量移除某个实例中的所有事件的监听器: