CODEWITHSUNDEEP
c#asp.netfile-upload
Arindam Das
Arindam Das

Reputation: 699

Error while trying to upload a file

I have a file upload control and a button:

<asp:FileUpload ID="venfileupld" runat="server" />
<asp:Button ID="venupld1" runat="server" Text="Upload" OnClick="venupld1_Click" />

In the button click event I am doing this:

string name = venfileupld.PostedFile.FileName;

    string filepath = Server.MapPath("upload_excel/") + name;
    venfileupld.PostedFile.SaveAs(filepath);

 writetoven();

But it's giving me an error.

My first question is why I am getting an error on the line:

string name = venfileupld.PostedFile.FileName;

It's giving null that the uploader doesn't have any file.

And the second question is how I get the file that I can pass on the function named:

 writetoven();

Any help?

Upvotes: 1

Views: 828

Answers (4)

Tim Schmelter
Tim Schmelter

Reputation: 460058

Are you using ASP.NET Ajx with an UpdatePanel? ... yes i am using ajax and updatepanel

FileUpload doesn't work inside of an UpdatePanel. You must use an AsyncFileUpload from the ASPNET AJAX control Toolkit.

Look here for more details: http://knowledgebaseworld.blogspot.de/2009/02/file-upload-not-working-with-update.html

You should handle the UploadedComplete event of the AsyncFileUpload control:

private static List<string> allowedExtensions = new List<string>(new string[] {
".xls",
".xlsx"
});

protected void AsyncFileUpload1_UploadedComplete(object sender, AjaxControlToolkit.AsyncFileUploadEventArgs e)
{
    if (e.state == AjaxControlToolkit.AsyncFileUploadState.Success) {
        string fileExt = System.IO.Path.GetExtension(e.filename);
        if (allowedExtensions.Contains(fileExt)) {
            string fileName = System.IO.Path.GetFileName(e.filename);
            string dir = Server.MapPath("upload_excel/");
            string path = Path.Combine(dir, fileName);
            AsyncFileUpload1.PostedFile.SaveAs(path);
            AsyncFileUpload1.FileContent.Close();
        } else {
            // wrong extension
        }
    } else {
        // log and show error
    }
}

Upvotes: 0

MMK
MMK

Reputation: 3721

Try Following:

Code behind:

protected void venupld1_Click(object sender, EventArgs e)
    {
        string name = venfileupld.FileName;
        string filepath = Server.MapPath("~/upload_excel/") + name;
        venfileupld.PostedFile.SaveAs(filepath);
     }

Code inline:

<asp:UpdatePanel ID="UpdatePanel1" runat="server"  UpdateMode="conditional">
    <ContentTemplate>
    <asp:FileUpload ID="venfileupld" runat="server" />
    <asp:Button ID="venupld1" runat="server" Text="Upload" OnClick="venupld1_Click" />
    </ContentTemplate>
    <Triggers>
    <asp:PostBackTrigger ControlID="venupld1" />
    </Triggers>
 </asp:UpdatePanel>

Hope this helps.

Upvotes: 0

Prashant Lakhlani
Prashant Lakhlani

Reputation: 5806

First of all, make sure you are using enctype=multipart/form-data in your form tag. That will allow file upload controls to be posted to asp.net server and you will start receiving data in venfileupld.PostedFile object and other properties.

Use venfileupld.HasFile and venfileupld.ContentLength properties to make sure file is uploaded and is not 0kb.

-- update --

Based on the fact that you are using update panel, you can try adding a postback trigger like

 <Triggers>
  <asp:PostBackTrigger ControlID="btnUploadControlId" />
 </Triggers>

----- end of update ----

Add more details if this doesn't solve your problem.

Upvotes: 0

Vimal bhatt
Vimal bhatt

Reputation: 285

You have to check upload control has file by its property "HasFile" before assign a file name to variable "name" you can see best example from following link : http://asp-net-example.blogspot.in/2008/10/fileupload-control-example.html

Upvotes: 1

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