on

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小牛编辑

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2023-12-01

描述 (Description)

它将事件绑定到对象和回调函数。每当触发事件时，它都会执行回调。

语法 (Syntax)

object.on(event, callback function, [context])

参数 (Parameters)

event - 它绑定一个对象。
callback - 它是对代码的引用。
context - 它是一个可以传递给回调函数的对象。

例子 (Example)

<!DOCTYPE html>
<html>
   <head>
      <title>Event On Example</title>
      <script src = "https://code.jquery.com/jquery-2.1.3.min.js"
         type = "text/javascript"></script>
      <script src = "https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.2/underscore-min.js"
         type = "text/javascript"></script>
      <script src = "https://cdnjs.cloudflare.com/ajax/libs/backbone.js/1.1.2/backbone-min.js"
         type = "text/javascript"></script>
   </head>
   <body>
      <script type = "text/javascript">
         //Here creating an object 'myVal' and extending with Backbone.Events method
         var myVal = _.extend({name:'xnip!!!'}, Backbone.Events);
         // The on() method will bind callback function to an object and 
         // invoked whenever an event triggers
         myVal.on('myFunc', function () {
            document.write("The triggered value is: ");
            document.write(this.name);//The name will get display by referring the current object
         });
         //It triggers the 'myFunc' event on object 'myVal'
         myVal.trigger('myFunc');
      </script>
   </body>
</html>