前端基本是需要模拟出来一个form表单，通过form表单来请求一个action，然后这个action返回一个Stream，这里使用JavaScript来构造一个html表单，然后在自动提交去请求服务action

CreateForm: function (actionUrl, data) {if ($("#downloadFrame").length > 0) {$("#downloadFrame").remove();$("#downloadQueryForm").remove();} // modal.showLoading()var $iframe = $('').appendTo($("body"));$('
     
      
     
').appendTo("body");document.forms["downloadQueryForm"].submit();}

　　

actionUrl就是后台api接口，data是参数。 然后后台接口api返回的时候，返回值修改一些类型。

public HttpResponseMessage DownloadFile()        {            var contextRequest = (HttpContextWrapper)Request.Properties["MS_HttpContext"]; //获取传统context'            var filePath = contextRequest.Request.MapPath("/ExportFiles");            try            {                var downloadFileName = "xxx.jpn";                var bytes = File.ReadAllBytes(filePath);                MemoryStream ms = new MemoryStream(bytes);                ms.Flush();                ms.Position = 0;                HttpResponseMessage response = new HttpResponseMessage(HttpStatusCode.OK);                response.Content = new StreamContent(ms);                response.Content.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("application/octet-stream");                response.Content.Headers.ContentDisposition = new System.Net.Http.Headers.ContentDispositionHeaderValue("attachment")                {                    FileName = downloadFileName                };                return response;            }            catch (Exception ex)            {                return new HttpResponseMessage();            }        }