Javascript的AJAX功能收益不确定，而不是真/假

问题描述：

我有发出AJAX调用（通过jQuery）的函数。在完整部分我有一个函数，上面写着：

I have a function that issues an AJAX call (via jQuery). In the complete section I have a function that says:

complete: function(XMLHttpRequest, textStatus)
{
    if(textStatus == "success")
    {
        return(true);
    }
    else
    {
        return(false);
    }
}

不过，如果我把这个像这样：

However, if I call this like so:

if(callajax())
{
    //  Do something
}
else
{
    // Something else
}

首先是永远不会被调用。

The first is never called.

如果我把一个警报（textStatus）在完整功能我得到真正的，但不是说功能之前，返回未定义。

If I put an alert(textStatus) in the complete function I get true, but not before that function returns undefined.

这将有可能通过一个回调函数来我 callajax（）的方法？像：

Would it be possible to pass a callback function to my callajax() method? Like:

callajax（函数（）{//成功}，功能（）{//错误}，功能（）{//完成}）;

答

完整是回调的功能。它将由Ajax对象调用 - 异步！ - 操作完成时。有没有办法让你赶上回调的结果，只有在Ajax对象能做到这一点。

complete is a callback function. It will be invoked by the Ajax object - asynchronously! - when the operation is complete. There is no way for you to catch the callback's result, only the Ajax object could do that.

您 callajax（）功能 - 你不可见的功能，但我认为它只是使Ajax调用 - 无法返回调用的结果（=的响应头和身体），作为呼叫将不会被说完呢，当你退出 callajax（）的功能。

Your callajax() function - you're not showing that function but I assume it simply makes the Ajax call - can not return the call's result (= the response headers and body), as the call will not have been finished yet when you exit the callajax() function.

更新：它的是的也很可能使同步AJAX调用。感谢@Andris指出这一点。在jQuery中，您需要将异步选项设置为假：文档的此处。然而，即使是那些使用标准的回调函数，据我所看到的，所以你想要回国的方法假或真仍可能无法正常工作。

Update: It is also well possible to make synchronous AJAX calls. Thanks to @Andris for pointing this out. In jQuery, you need to set the async option to false: Docs here. However, even those use the standard callback functions as far as I can see, so your desired method of returning false or true may still not work.

Javascript的AJAX功能收益不确定，而不是真/假

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