FileUpload control - file size detection

[E. Kwong]

Is it possible to obtain the file size at the moment when the file path/name
populates the textbox portion of the FileUpload control?

Thx

 

[Brennan Stehling]

The HTML markup to do file upload is the INPUT element with "file" set
as the TYPE. You can read the specifications on it here.

http://www.w3.org/TR/html4/interact/forms.html

Unfortunately it does not support a file size limit with an attribute
on that markup element. That would be an obvious feature, but perhaps
it is not allowed due to security concerns although the size should be
a safe value to expose to an untrusted website. This is touchy because
it is one of the few features of a web browser which gives you access
to the user's file system.

I just browsed a site I use which has an upload features and used
Firefox's Firebug add-on to browse the DOM for the upload form and it
did not show the size of the file I had selected.

If there is a way to limit file size for uploads I would also like to
know it.

Brennan Stehling
http://brennan.offwhite.net/blog/

 

[Michael D. Ober]

If you have access to the web-site's configuration file, you can limit the
upload size via the Web.config file as follows:

<system.web>
<httpRuntime maxRequestLength="<max size in KB>"/>
</system.web>

Mike Ober.

 

[Steve C. Orr [MVP, MCSD]]

That works but not at the moment the filename is put in the upload box as
the original poster requested.

I don't know of any way to meet that requirement other than a thick client
such as a windows forms component (with the appropriate permissions) or an
ActiveX control.

--
I hope this helps,
Steve C. Orr
MCSD, MVP, CSM
http://SteveOrr.net

 

[Michael D. Ober]

Agreed - it doesn't answer OPs original question, but it can at least block
arbitrarily large files from being uploaded, which I suspect was the intent.

Mike.

 

[Brennan Stehling]

This would be an ideal space for a Click-Once application which uploads
files using a desktop application. It could connect to a web service
and send 1000kb chunks and monitor the progress for the user. It could
even support a stop and resume process.

Such functionality is strongly lacking from the web browsers.

http://search.msdn.microsoft.com/se...dn2.microsoft.com/en-us/library/142dbbz4.aspx

Brennan Stehling
http://brennan.offwhite.net/blog/

 

[Steve C. Orr [MVP, MCSD]]

Yes I've thought about that but security is the main problem.
By default click once applications don't have much access to the user's hard
drive.

--
I hope this helps,
Steve C. Orr,
MCSD, MVP, CSM, ASPInsider
http://SteveOrr.net