$.ajax异步请求无法下载文件到浏览器本地的问题

//open这种方式有个弊端，就是转的参数值不能太大，所以只能用jquery创建表单form在提交（ajax异步请求不会触发浏览器下载文件的功能）
           var userAgent = navigator.userAgent; //取得浏览器的userAgent字符串
              if (userAgent.indexOf("compatible") > -1 && userAgent.indexOf("MSIE") > -1) {//判断是否IE浏览器
                       window.location.href(url);
                   }else{
                       window.open(url,"xxx");
                   }

方法1，window.open

//导出
               $("#exportData").click(function() {  
                   var myqx =document.getElementById("qxId").contentWindow.document.getElementById("myqx");
                   var myqxD = $(myqx).val();
                   var id = $("input[name='myHidId']").val();
                   var url = __ctx+'/hyddrbnew/hyddrbnew/hyddrb/exportExcelDdrb.ht';
                   
                   var form = $("<form>");
                   form.attr("style","display:none");
                   form.attr("target","_blank");
                   form.attr("method","post");
                   form.attr("action",url);
                   var input1 = $("<input>");
                   input1.attr("type","hidden");
                   input1.attr("name","id");
                   input1.attr("value",id);
                   
                   var input2 = $("<input>");
                   input2.attr("type","hidden");
                   input2.attr("name","myqxD");
                   input2.attr("value",myqxD);
                   
                   $("body").append(form);
                   form.append(input1);
                   form.append(input2);
                   form.submit();
                   form.remove();
  
               });