为什么我不能在Javascript中滚动循环？ [英] Why can't I roll a loop in Javascript?

问题描述

我正在使用一个网页，使用dojo，并有一个数字（在我的测试用例中，但一般变量）的项目小部件。我调用dojo.addOnLoad（ini​​t），在我的init（）函数中，我有这些行：

I am working on a web page that uses dojo and has a number (6 in my test case, but variable in general) of project widgets on it. I'm invoking dojo.addOnLoad(init), and in my init() function I have these lines:

dojo.connect(dijit.byId("project" + 0).InputNode, "onChange",  function() {makeMatch(0);});
dojo.connect(dijit.byId("project" + 1).InputNode, "onChange",  function() {makeMatch(1);});
dojo.connect(dijit.byId("project" + 2).InputNode, "onChange",  function() {makeMatch(2);});
dojo.connect(dijit.byId("project" + 3).InputNode, "onChange",  function() {makeMatch(3);});
dojo.connect(dijit.byId("project" + 4).InputNode, "onChange",  function() {makeMatch(4);});
dojo.connect(dijit.byId("project" + 5).InputNode, "onChange",  function() {makeMatch(5);});

并更改我的项目窗口小部件的事件调用makeMatch函数。但是如果我用一个循环替换它们：

and change events for my project widgets properly invoke the makeMatch function. But if I replace them with a loop:

for (var i = 0; i < 6; i++) 
    dojo.connect(dijit.byId("project" + i).InputNode, "onChange",  function() {makeMatch(i);});

相同的makeMatch（）函数，同样的init（）调用，同样的一切 - 只是滚动我的调用into一个循环 - makeMatch函数从不被调用;对象没有连接。

same makeMatch() function, same init() invocation, same everything else - just rolling my calls up into a loop - the makeMatch function is never called; the objects are not wired.

发生了什么，我如何解决它？我尝试使用dojo.query，但它的行为是与for循环的情况相同。

What's going on, and how do I fix it? I've tried using dojo.query, but its behavior is the same as the for loop case.

推荐答案

问题在处理闭包。请尝试：

this is a common problem when dealing with closures. try this:

for (var i = 0; i < 6; i++) {
    (function(i){
      dojo.connect(dijit.byId("project" + i).InputNode, "onChange",  function()   {makeMatch(i);});
    }(i));
}

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