Question

我正在使用C＃ASP.NET代码并尝试在表单的post请求中下载文件。这是我的示例代码。

    [HttpPost]
    public ActionResult PostMethodName(PostModel inputModel)
    {
        if (ModelState.IsValid)
        {
//other code is removed.
 //Writing this for the test 
            //Download Method call
            DownloadCertificate("This is the test file to download.");

            var statusHtml = RenderViewToString("Status",
            new ErrorMsgModel
            {                    
                IsSuccess = true,
                ErrorDesc = "desc"
            });

            return Json(new { IsSuccess = true, ErrorDescription = 
statusHtml}, JsonRequestBehavior.AllowGet);
        }
        var statusHtml1 = RenderViewToString("Status",
            new ErrorMsgModel
            {
                IsSuccess = false,
                ErrorDesc = "desc"
            });
        statusHtml1 = statusHtml1.Replace("'", "\\'");
        statusHtml1 = statusHtml1.Replace(Environment.NewLine, "");
        return Json(new { IsSuccess = false, ErrorDescription = statusHtml1 
}, JsonRequestBehavior.AllowGet);
    }

从此方法调用的下载方法。

public ActionResult DownloadCertificate(string content)
    {
        //Certificate Download
        const string fileType = "application/pkcs10";
        string fileName = "Certificate" + DateTime.Today.ToString(@"yyyy-MM-dd") + ".csr";
        var fileContent = String.IsNullOrEmpty(contrnt) ? "" : contrnt;
        byte[] fileContents = Encoding.UTF8.GetBytes(fileContent);
        var result = new FileContentResult(fileContents, fileType) { FileDownloadName = fileName };
        return result;
    }

文件下载无效，后期功能正常工作。

Answer 1

您的DownloadCertificate方法会返回一个值，但您永远不会在PostMethodName方法中使用返回值。

鉴于您从该方法返回json，我建议您在响应中返回指向文件结果的直接链接。然后，消费客户端可以启动下载。类似的东西：

return Json(new { IsSuccess = true, Location = Url.Action("DownloadContent")});

或者，您可以考虑采用更加安静的方法，并从后期操作中返回302响应：

if (ModelState.IsValid)
{
    // you code here
    return RedirectToAction("Controller", "DownloadContent", new {content = "myContent"});
}

这可能会根据您的客户端透明地进行下载，同时保持Post-Redirect-Get模式

Answer 2

[HttpPost]
public ActionResult DownloadCertificate(PostModel inputModel, string content)
{
    if(!ModelState.IsValid){return Json(new {Success=false,//error descr})}
    //Certificate Download
    const string fileType = "application/pkcs10";
    string fileName = "Certificate" + DateTime.Today.ToString(@"yyyy-MM-dd") + ".csr";
    var fileContent = String.IsNullOrEmpty(contrnt) ? "" : contrnt;
    byte[] fileContents = Encoding.UTF8.GetBytes(fileContent);
    var result = new FileContentResult(fileContents, fileType) { FileDownloadName = fileName };
    return result;
}

在您之前的代码中，您不使用DownloadCertificate结果，只需执行它即可。

在FORM POST请求中下载文件C＃

2 个答案: