BackboneJS off事件

2018-01-04 18:05 更新

描述

此事件从对象中删除回调函数或所有事件。

语法

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

参数

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

<!DOCTYPE html>
  <head>
    <title>Event Off 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:'hello'}, Backbone.Events);
        var myFunc = function () {
           document.write('Hello');
        };
        var myFunc1 = function () {
           document.write('Welcome to TutorialsPoint');
        };

        //The on() method will bind the callback function to objects 'myFunc' and 'myFunc1'
        myVal.on('log',myFunc);
        myVal.on('log',myFunc1);
        document.write('Before using off event, values will be: ');

        //trigger() method callbacks for the given event and display the text defined in the 'myFunc' and 'myFunc1' functions
        myVal.trigger('log');

        //The off() method removes the callback for 'myFunc' and logs only text of 'myFunc1'
        myVal.off('log',myFunc);

        document.write("<br>");
        document.write('After using off event, values will be: ');
        myVal.trigger('log');
     </script>
   </body>
</html>

输出

让我们执行以下步骤，看看上面的代码如何工作：

将上面的代码保存在off.htm文件中
在浏览器中打开此HTML文件。

Before using off event, values will be: HelloWelcome to TutorialsPoint
After using off event, values will be: Welcome to TutorialsPoint

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