Error when trying upload file aspx / C#

Question

I have the following C# code:

string File = "../images/main/profile-icon.png";
if (Request.ContentLength != 0)
{
    int Size = Request.Files[0].ContentLength / 1024;
    if (Size <= 512)
    {

        string LocalFile = Request.Files[0].FileName;
        int dot = LocalFile.LastIndexOf('.');
        string FileType = LocalFile.Substring(dot + 1);
        if (FileType == "gif" || FileType == "jpg" || FileType == "png" || FileType == "GIF" || FileType == "JPG" || FileType == "PNG")
        {
            int LastIndex = LocalFile.LastIndexOf(@"\") + 1;
             File = LocalFile.Substring(LastIndex, LocalFile.Length - LastIndex);
            File = DateTime.Today.ToString();
            string Path = Server.MapPath(" ../images/profiles") + "..\\" + File;
            Request.Files[0].SaveAs(Path);
        }
    }
    else
    {
        Response.Write("The file is too big !");
    }
}
else
{
    Response.Write("Unknown Error !");
}

The problem is that in the third code line I get the following error:

Index was out of range. Must be non-negative and less than the size of the collection.

this is the form HTML source:

<form name="Register" runat="server" style="margin-top: 15px;" onsubmit="return validateProfile('Register');">
    <p>
       photo:
        <input type="file" name="File" style="margin-right:10px;" />
    </p>
</form>

My question is why and how can I fix this?

Wish for help, thanks!

Answer 1

It appears that the Files array has no elements, maybe you can add a check:

if(Request.Files.Count > 0)
{
   // continue here ...
}

This probably means that you're not uploading the file correctly and it's missing from the request.

EDIT: Try to set the enctype="multipart/form-data" in your form tag. So it will become something like:

<form name="Register" runat="server" style="margin-top: 15px;" onsubmit="return validateProfile('Register');" enctype="multipart/form-data">