如何在内部Ajax调用中获取函数的返回值-JQuery

那是因为

$.ajax()

如果您将代码编辑为以下内容：

function getMessageCount(callback) {    var count;    $.ajax({       type: "POST",       url: "http://localhost:43390" + "/services/DiscussionWidgetService.asmx/GetMessageCount",       dataType: "json",       contentType: "application/json; charset=utf-8",       success: function (data) {    count = data.d;         if(typeof callback === "function") callback(count);      } //success   });}

然后，当您调用它时：

getMessageCount(function(count){  console.log(count);});