Get FileSize in Server is always zero - asp.net

Question

I'm doing a file upload function in my ASP.NET MVC web system. The file upload function is working, so the next step I do is to validate the file size.
Please see the attached codes
Partial form GEDocumentInfoForm.ascx:
<input type="file" name = "Files" class = "multi" id = "myFile"/>
Main Form Create.aspx
<asp:Content ID="Content4" ContentPlaceHolderID="ContentCph" runat="server">
<script type="text/javascript">
$(document).on('click', '#btnCreateDocument', function () {
$('#btnCreateDocument').attr('disabled', 'disabled'); // prevent resubmit
Checksize()
document.body.style.cursor = 'wait';
});
function Checksize() {
alert(document.getElementById("myFile").tagName);
var k = document.getElementById("myFile").files[0].size;
alert("file size in KB " + k / 1024);
}
</script>
<% Using (Html.BeginForm("Create", "GEDocument", FormMethod.Post, New With {.enctype = "multipart/form-data", .id = "form"}))%>
<input type="submit" name="Save" value="<%= Detail.Save %>" id="btnCreateDocument" />
<div id="Div1">
<% Html.RenderPartial("GEDocumentInfoForm", Model) %>
</div>
<% End Using%>
</asp:Content>
The file size validation (not more than 2048B) was working fine in localhost. So, after that I published it and deploy in my development server. When I run it, somehow it can pass through my validation. After check in debug mode of web browser, it returns 0 for the file size.
var k = document.getElementById("myFile").files[0].size;
I've tried to search solutions to see if anyone hit the similar issue before. End up, I have to use server validation in my Controller.
Dim fileZs As HttpFileCollectionBase = Request.Files
For z As Integer = 0 To (fileZs.Count - 1)
Dim file As HttpPostedFileBase = fileZs(z)
If Not IsNothing(file) AndAlso (file.ContentLength / 1024) > 2048 Then
errors.Concat(New RuleViolation(Message.EmailMustHaveValue, "SelectedToEmails"))
End If
Next
Web.Config (added the configuration so that it can pass ActionFilterAttribute in Controller due to Maximum request too long)
<system.web>
<httpRuntime maxRequestLength="1048576" />
</system.web>
I think that server validation is not user-friendly. I wish there are some answers from the experts if anyone faced the issue like me in doing Client validation to check file size in file upload feature.
Why is it always return 0 after published to development server?
Is it related to server security? As I know we are getting FileName as C:\fakePath\myFileName. Could it be some relationship over here?

Answer 1

here a full working example, note Request.Files is an array, if you are sending only one file you need to pick first item.
the right property to check is ContentLength
also check if in your folder the uploaded file exists after upload, because you need to have write permission in the folder where you are uploading
[HttpPost]
public ActionResult Upload()
{
if (Request.Files.Count > 0)
{
var file = Request.Files[0];
if (file != null && file.ContentLength > 0)
{
var fileName = Path.GetFileName(file.FileName);
var path = Path.Combine(Server.MapPath("~/Images/"), fileName);
file.SaveAs(path);
}
}
//............
}