Question

我想向用户提示保存对话框。文件taype是.wav。行动如下所示

  public ActionResult MergeSelectedRecords(string mergeFileName, List<String> selectedRecords)
    {
       string urlFilePath=GetFilePath(); //get virtual path of file.       

       ControllerContext.HttpContext.Response.AddHeader("content-disposition",        "attachment; filename=" + "cccc");    

       string filePath = ControllerContext.HttpContext.Server.MapPath(urlFilePath);
       return File(filePath, ".wav");
      }

一个sampl文件路径是'http：/ localhost：2694 / DATA / MERGE / OUT / 1 / cccc'

但它显示如下所示的错误

'http:/localhost:2694/DATA/MERGE/OUT/1/cccc' is not a valid virtual path.

这是向用户提示保存文件对话框的正确方法吗？

修改

有时用户没有文件可用。所以我只想在urlFilePath =“”。

时显示警告

如果没有可用的文件路径我怎么能返回一个空的结果。并向用户发出警报..我想要的东西在下面显示

  public ActionResult MergeSelectedRecords(string mergeFileName, List<String> selectedRecords)
    {
       string urlFilePath=GetFilePath(); //get virtual path of file.       
     if(urlFilePath!="")
      {
       ControllerContext.HttpContext.Response.AddHeader("content-disposition",        "attachment; filename=" + "cccc");    

       string filePath = ControllerContext.HttpContext.Server.MapPath(urlFilePath);
       return File(filePath, ".wav");
      }
     else
      {
           //what i return here? If it possible i only want to display an alert .But the page user viewing cannot refreshed
      } 
      }

Answer 1

您传递给urlFilePath方法的MapPath参数必须是以~/开头的同一网站中的相对网址。例如：

public ActionResult MergeSelectedRecords(string mergeFileName, List<String> selectedRecords)
{
    string urlFilePath = "~/Files/ccc.wav";
    string filePath = Server.MapPath(urlFilePath);
    return File(filePath, ".wav", "ccc");
}

如果网址不是您网站的一部分，则需要先下载该文件。例如：

public ActionResult MergeSelectedRecords(string mergeFileName, List<String> selectedRecords)
{
    using (var client = new WebClient())
    {
        byte[] file = client.DownloadData("http://foo.com/ccc.wav");
        return File(file, ".wav", "ccc");
    }
}

提示文件保存-MVC

1 个答案: