发布于 2015-08-14 15:21:44 | 120 次阅读 | 评论: 0 | 来源: 网络整理
它同样就像listenTo事件，当监听发生在回调函数被删除之前的一次。
object.listenToOnce(other, event, callback)
<!DOCTYPE html>
<head>
<title>Event Once 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">
//Create an object 'myVal' and 'myVal1' and extend them using Backbone.Events method
var myVal = _.extend({name:'Saurav Ganguly'}, Backbone.Events);
var myVal1 = _.extend({name:'Sachin Tendulkar'}, Backbone.Events);
//created the 'listenMe' callback function and invoked when one object listen to particular event on another object
var listenMe = function(){
document.write("The value is: ");
document.write(this.name);
};
//The object 'myVal1' listen once for the 'listenMe' event triggered on object 'myVal'
myVal1.listenToOnce(myVal, 'listenMe', listenMe);
//The 'myVal' has no listenMe event and display the value of 'myVal1'
myVal.trigger('listenMe');
</script>
</body>
</html>
让我们进行以下步骤来看看上面的代码工作：
保存上述代码在文件listentoonce.html
在浏览器中打开这个HTML文件。