下载链接将在系统下载路径中下载该文件

Question

fileinnfo的错误代码

FileInfo File = new FileInfo(Server.MapPath("/Content/ExcelFiles/SalesTarget.xlsx"));

        if (File != null)
        {
            int Size = Convert.ToInt32(File.Length);

            string FileName = File.FullName;
            int Position = FileName.LastIndexOf("\\");
            FileName = FileName.Substring(Position + 1);
             string test = File.GetType().ToString();
            string filepath = Server.MapPath("/Content/ExcelFiles/SalesTarget.xlsx");
            string ContentType = MimeMapping.GetMimeMapping(Server.MapPath("/Content/ExcelFiles/SalesTarget.xlsx"));
            byte[] FileData = new byte[Size];
            char[] chars = Encoding.Unicode.GetChars(FileData);

            StreamReader reader = new StreamReader(filepath);
            reader.Read(chars, 0, Size);     // Throwing error here
            Response.ContentType = ContentType;
            StringBuilder SB = new StringBuilder();

            SB.Append("filename=");
            SB.Append(FileName);

            Response.AddHeader("Content-Disposition", SB.ToString());
            Response.BinaryWrite(FileData);
            Response.Flush();
            Response.End();
            //File..Read(FileData, 0, Size);
        }

使用Httppostedfile类运行代码：

 HttpPostedFileBase File = Request.Files["FileToLoad"];

        if (File != null)
        {
            int Size = File.ContentLength;

            if (Size <= 0)
            {
                ViewData["ERROR"] = "You uploaded an empty file,please browse a valid file to upload";
                return View("../Shared/Error");
            }

            string FileName = File.FileName;
            int Position = FileName.LastIndexOf("\\");
            FileName = FileName.Substring(Position + 1);
            string ContentType = File.ContentType;
            byte[] FileData = new byte[Size];
            File.InputStream.Read(FileData, 0, Size);

            theModel.AddAFile(FileName, Size, ContentType, FileData);
        }

我想从目录下载现有文件而不是使用httppostedfile，所以我在读取文件数据时遇到错误。