【疑难杂症】Asp.net Ajax请求后台下载文件无反应不下载等问题 （已解决）

下载文件没啥技术含量，但是我遇到个问题，执行代码后没反应，我前端是Ajax触发的。后台听说这是Ajax才会出现的问题，跟返回机制有关还好找到了解决方案

1定义一个函数

用jquery的方式组织一个字符串，模拟提交一个form请求，也就是动态渲染表单，提交表单后再删除。

      jQuery.download = function (url, data, method) {
        // 获取url和data
        if (url && data) {
            // data 是 string 或者 array/object
            data = typeof data == 'string' ? data : jQuery.param(data);
            // 把参数组装成 form的  input
            var inputs = '';
            jQuery.each(data.split('&'), function () {
                var pair = this.split('=');
                inputs += '';
            });
            // request发送请求
            jQuery('

' + inputs + '

')
        .appendTo('body').submit().remove();
        };
    };

2调用

 $.download("/Salary/Api.aspx", "type=DownloadSalaryTemplate", 'post');

3后台

 try
                    {
                       
                        string fileName = "工资导入模板.xls";
                        var filePath = System.Web.Hosting.HostingEnvironment.MapPath(@"~/Config/EmployeeSalary.xls");
                        FileInfo fileInfo = new FileInfo(filePath);

                        if (fileInfo.Exists == true)
                        {
                             HttpContext.Current.Response.Clear();
                             HttpContext.Current.Response.ClearContent();
                             HttpContext.Current.Response.ClearHeaders();
                             HttpContext.Current.Response.AddHeader("Content-Disposition", "attachment;filename=" + fileName);
                             HttpContext.Current.Response.AddHeader("Content-Length", fileInfo.Length.ToString());
                             HttpContext.Current.Response.AddHeader("Content-Transfer-Encoding", "binary");
                             HttpContext.Current.Response.ContentType = "application/vnd.ms-excel";
                             HttpContext.Current.Response.ContentEncoding = System.Text.Encoding.GetEncoding("gb2312");
                             HttpContext.Current.Response.WriteFile(fileInfo.FullName);
                             HttpContext.Current.Response.Flush();
                        }
                    }
                    catch(Exception ex)
                    {
                    }
                    finally
                    {
                        HttpContext.Current.Response.End();
                    }
                    return;

}

 

      public FileResult DownloadUserTemplate()
        {
            string filePath = Server.MapPath("~/Content/UserImportTpl.xls");//路径
            return File(filePath, "text/plain", "玩家导入模板.xls"); //welcome.txt是客户端保存的名字

        }