Why doesn't the hyperlink open the file?

问题

Earlier developer had put this code using a label and it was turned into a hyperlink during the run time.

<asp:Label ID="lbl_Attachment" runat="server">
</asp:Label>

lbl_Attachment.Text = "<a href='../Uploads/" + 
                      ds_row["Attachment"].ToString() + "'>" + 
                      ds_row["Attachment"].ToString() + "</a>";

But this is not working. So I changed the code to the following to open the any file (image/pdf/word) in a new browser tab and the error persists:

      hyperlinkAppDoc.NavigateUrl = 
          ResolveUrl("../Uploads/" + 
          ds_row["Attachment"].ToString());
      hyperlinkAppDoc.Target = "_blank";

What can I do to fix this issue? MIME types are available in the IIS.

UPDATE: I am trying out a different approach. However the Server.MapPath is poiting at local drive instead of wwwroot. How can I point the path to wwwroot folder?

string pdfPath = Server.MapPath("~/SomeFile.pdf");
WebClient client = new WebClient();
Byte[] buffer = client.DownloadData(pdfPath);
Response.ContentType = "application/pdf";
Response.AddHeader("content-length", buffer.Length.ToString());
Response.BinaryWrite(buffer);

回答1:

You could have used asp.hyperlink. Like following

<asp:HyperLink id="hyperlink1" NavigateUrl="<set_from_code_behind>" Text="Text to redirect" runat="server"/>

And set NavigateUrl from code behind as following.

hyperlink1.NavigateUrl= "Uploads/" + ds_row["Attachment"].ToString();

回答2:

In your situation, I suggest you to add one key in <appSettings> tag in your web config file.

<appSettings>    
    <add key="WebsiteURL" value="http://localhost:1234/WebsiteName/"/>
</appSettings>

Next step is to take one hyperlink in your .Aspx file.

<asp:HyperLink ID="HyperLink1" runat="server" Target="_blank"></asp:HyperLink>

In code behind concatenate AppSettings Key + Download file path from root.

string base_path = ConfigurationSettings.AppSettings["WebsiteURL"];
HyperLink1.NavigateUrl = base_path + "Uploads/" + ds_row["Attachment"].ToString();

Please let me know if you have any questions.

回答3:

All the sweat was due to path issue. Old code and new code works. There's no need for a web client code.

The upload path was set here:

public static string UploadDirectory = ConfigurationManager.AppSettings["UploadDirectory"];

It was pointing to a different directory in the root other than where the application was. Therefore the files were only uploaded but never picked up.

I changed it to AppDomain.CurrentDomain.BaseDirectory for now. After we talk with the users, we will set it accordingly.

来源：https://stackoverflow.com/questions/29910618/why-doesnt-the-hyperlink-open-the-file

标签

ASP.NET

file

c#-4.0

hyperlink