Question

我有这个：

var MyObject = function(){   
   this.url = "monurl";   
   this.mavar = "";   
   this.Load = function(){
     var callback = {
       success: function(o){
         mavar = o.responseXML.getElementsByTagName("montag")[0].firstChild.nodeValue;
       }
     }
     YAHOO.util.Connect.asyncRequest('GET',url,callback);
} }

无法访问mavar变量。我怎么能这样做？

Answer 1

我相信你可以为回调设置范围参数。所以你应该能够做类似以下的事情。

var MyObject = function(){   
   this.url = "monurl";   
   this.mavar = "";   
   this.Load = function(){
     var callback = {
       success: function(o){
         this.mavar = o.responseXML.getElementsByTagName("montag")[0].firstChild.nodeValue;
       },
       scope: this
     }
     YAHOO.util.Connect.asyncRequest('GET', this.url, callback);
} }

Answer 2

保存this变量：

var MyObject = function() {   
   this.url = "monurl";   
   this.mavar = "";   
   this.Load = function() {
     var me = this;
     var callback = {
       success: function(o) {
         me.mavar = o.responseXML.getElementsByTagName("montag")[0].firstChild.nodeValue;
       }
     }
     YAHOO.util.Connect.asyncRequest('GET',url,callback);
  }
}

Answer 3

你也可以这样做：

var MyObject = new function(){   
   this.url = "monurl";   
   this.mavar = "";   
   this.Load = 
   (function(that){ 
        return function(){
            var callback = {
                success: function(o){
                    that.mavar = o.responseXML.getElementsByTagName("montag")[0].firstChild.nodeValue;
                }
            }
            YAHOO.util.Connect.asyncRequest('GET',url,callback);
        } 
    })(this);
};

Answer 4

在我的对象中，我添加了一个引用它的变量：

var selfMyObject = this;

我在成功回调中将this.mavar替换为selfMyObject.mavar，它运行正常。

Answer 5

处理此问题的最佳方法是让YUI进行范围校正，因为内置支持。这是文档页面，告诉您如何执行此操作。 http://developer.yahoo.com/yui/connection/#scope

var MyObject = function() {
    this.url = "monurl";
    this.mavar = "";
    this.Load = function() {
        var callback = {
            success: function(o){
                this.mavar = o.responseXML.getElementsByTagName("montag")[0].firstChild.nodeValue;
            },
            scope: this
        }

        YAHOO.util.Connect.asyncRequest('GET', url, callback);
    }
}

如何在javascript YUI中访问回调对象中的全局变量而不使用window.variable？

5 个答案: