为什么我下载文件的代码会生成损坏的 PDF？ [关闭]

Question

使用以下代码下载 PDF 文件时遇到问题：

WebClient client = new WebClient();
client.DownloadFile(remoteFilename, localFilename);

虽然其他文件已成功下载，但当我下载并保存 PDF 文档时，当我尝试打开它时显示文档已修复错误。

Answer 1

检查这个方法，希望对你有帮助

        public static void DownloadFile(HttpResponse response,string fileRelativePath)
    {
        try
        {
            string contentType = "";
            //Get the physical path to the file.
            string FilePath = HttpContext.Current.Server.MapPath(fileRelativePath);

            string fileExt = Path.GetExtension(fileRelativePath).Split('.')[1].ToLower();

            if (fileExt == "pdf")
            {
                //Set the appropriate ContentType.
                contentType = "Application/pdf";
            }

            //Set the appropriate ContentType.
            response.ContentType = contentType;
            response.AppendHeader("content-disposition", "attachment; filename=" + (new FileInfo(fileRelativePath)).Name);

            //Write the file directly to the HTTP content output stream.
            response.WriteFile(FilePath);
            response.End();
        }
        catch
        {
           //To Do
        }
    }

Answer 2

@Syed Mudhasir： 它只是一条线:)

client.DownloadFileAsync(new Uri(remoteFilename, UriKind.Absolute), localFilename);

它将下载pdf文件。 :)

Answer 3

请尝试以下代码示例以下载 .pdf 文件。

 Response.ContentType = "Application/pdf"; 
 Response.AppendHeader("Content-Disposition", "attachment; filename=Test_PDF.pdf"); 
 Response.TransmitFile(Server.MapPath("~/Files/Test_PDF.pdf")); 
 Response.End();

Answer 4

这对我有用：

string strURL = @"http://192.168.1.xxx/" + sDocumento;
WebClient req = new WebClient();
HttpResponse response = HttpContext.Current.Response;
response.Clear();
response.ClearContent();
response.ClearHeaders();
response.Buffer = true;
response.AddHeader("Content-Disposition", "attachment;filename=\"" + sDocumento + "\"");
byte[] data = req.DownloadData(strURL);
response.BinaryWrite(data);
response.End();

Answer 5

这些解决方案都不适合我，或者不完整。也许这篇文章是旧的，新版本的 .NET 使它更容易？无论如何，下面的小代码很好地为我完成了这项工作：

  static async Task DownloadFile(string url, string filePath)
  {
     using (var wc = new WebClient())
        await wc.DownloadFileTaskAsync(url, filePath);
  }

以及如何调用该方法：

Task.Run(async () => { await DownloadFile(url, filePath); }).Wait();

Answer 6

    public void DownloadPdf(String downloadLink, String storageLink)
    {
        using (WebClient wc = new WebClient())
        {
            wc.DownloadFile(downloadLink, storageLink);
        }
        Console.Write("Done!");
    }

    static void Main(string[] args)
    {
        Program test = new Program();
        test.DownloadPdf("*PDF file url here*", @"*save location here/filename.pdf*");
        Console.ReadLine();
    }

确保添加：使用 System.Net；

Answer 7

public void DownloadTeamPhoto(string fileName)
{
  string mimeType = MimeAssistance.GetMimeFromRegistry(fileName);
  Response.ContentType = mimeType;
  Response.AppendHeader("Content-Disposition", "attachment; filename=" + 
  Path.GetFileName(basePath + fileName)); //basePath= @"~/Content/
  Response.WriteFile(basePath + fileName); //basePath= @"~/Content/
  Response.End();

}

public static string GetMimeFromRegistry(string Filename)
{
  string mime = "application/octetstream";
  string ext = System.IO.Path.GetExtension(Filename).ToLower();
  Microsoft.Win32.RegistryKey rk = 
  Microsoft.Win32.Registry.ClassesRoot.OpenSubKey(ext);

  if (rk != null && rk.GetValue("Content Type") != null)
     mime = rk.GetValue("Content Type").ToString();

  return mime;
}