evaluate the size of a file BEFORE it gets uploade

ALEX_GRIM · May 8th, 2005, 08:52 PM

another question;
does anyone know the best way to determine the size of a file that's being uploaded via the html file input feild?
what i'm trying to do is limit the size of the pictures people can upload, but have no clue where to start, eg, the directoryinfo, binary*, etc, etc, so i want to ask someone with experience what they think the best method is to evaluate the size of a file in a pages _load/postback routine.
i already have the upload part working as far as simply uploading goes:

Code:

IF PAGE.IsPostBack THEN
DIM P13 AS String

IF (RIGHT(PIC.VALUE, 3)) = "jpg" THEN P13 = ".JPG"
IF (RIGHT(PIC.VALUE, 3)) = "JPG" THEN P13 = ".JPG"
IF (RIGHT(PIC.VALUE, 3)) = "gif" THEN P13 = ".GIF"
IF (RIGHT(PIC.VALUE, 3)) = "GIF" THEN P13 = ".GIF"
IF (RIGHT(PIC.VALUE, 3)) = "bmp" THEN P13 = ".BMP"
IF (RIGHT(PIC.VALUE, 3)) = "BMP" THEN P13 = ".BMP"
IF (RIGHT(PIC.VALUE, 3)) = "png" THEN P13 = ".PNG"
IF (RIGHT(PIC.VALUE, 3)) = "PNG" THEN P13 = ".PNG"


IF PIC.VALUE <> "" THEN
DIM CM2 AS OLEDBCOMMAND
DIM CN2 AS OLEDBConnection
DIM CMV2 AS String
CN2 = new OLEDBConnection("PROVIDER=MICROSOFT.JET.OLEDB.4.0;Data Source=Z:\WWW\DATA\MX.mdb")
CMV2 = "UPDATE PROFILE SET PIC" &NUM.TEXT & "='" &P13 &"' WHERE UNAME='" &UNAME.TEXT &"'"
CM2 = NEW OLEDBCOMMAND(CMV2,CN2)
cn2.open()
CM2.EXECUTENONQUERY()
CN2.Close
CN2 = NOTHING

Dim filepath As String
filepath = Path.Combine ("X:\www\profiles\USERS\" & UNAME.TEXT &"\", Path.GetFileName(DS222.Tables ("PROFILE").ROWS(0).ITEM(I).TOSTRING()))
If File.Exists(FilePath) Then
File.Delete(FilePath)
End IF

filepath = Path.Combine ("X:\www\profiles\USERS\" & UNAME.TEXT &"\", Path.GetFileName(NUM.TEXT & P13))
PIC.PostedFile.SaveAs(filepath)

END IF
RESPONSE.REDIRECT("PIC.ASPX?uname=" & UNAME.text)

END IF

i just need to figure out how to evaluate the file's size.
i tried to search this forum, and others for a good idea, but i guess this isn't that hot of a topic.
i don't really need a code example. if you could just tell me a good way to do it, i can look up the gory details myself, so it doesn't take too much of your time, but i'm not opposed to anyone offering further help.
thanks in advance: ALEX GRIM

---------------------------
A Black sheep moves easy in the darkness.
[email protected]
WWW.GRIMMUSIC.COM

ALEX_GRIM · May 8th, 2005, 11:24 PM

NEVERMInd guys, i got it figured out. but thanks anyway.
oh yeah, i guess i could post my soloution in case someone else has the same problem:
Code:

' "PIC" is the name of my html input control
IF PIC.POSTEDFILE.CONTENTLENGTH > 100 THEN
RESPONSE.WRITE("THIS IS TOO DAMNED BIG!!!<BR>")
EXIT SUB
ELSE
'do your thing

good luck

---------------------------
A Black sheep moves easy in the darkness.
[email protected]
WWW.GRIMMUSIC.COM

planoie · May 9th, 2005, 06:02 AM

Another possible way would be to set up the limit in the web config. Though I don't know off hand what the node is you'd need to change, I think there is a property somewhere to limit the size of the incoming request. This should cause the server to more quickly reject the request. (Not sure if the browser first sends the size of the request as a check before shipping off the whole thing, this might make for a faster rejection.) However, this wouldn't be as "user friendly" as your message.

-Peter

ALEX_GRIM · May 9th, 2005, 10:10 PM

ACTUALLY the browser does send some sort of header, but i don't know the syntax for accesing it's value, eg: "request.header('ContentLength')", so i just did it my way.

---------------------------
A Black sheep moves easy in the darkness.
[email protected]
WWW.GRIMMUSIC.COM

planoie · May 10th, 2005, 03:15 PM

CONTENT_LENGTH will return the complete size of the entire posted form (not just the posted file). This wouldn't be that bad to check because from a percentage standpoint the size of the file will most likely be the largest portion of the request.

Accessing the value of the posted size won't be of much use in rejecting the request however. The problem is that the entire request will get uploaded to the server before the IIS process hands the request off to the ASP.NET worker process. So I don't see how the delay of a large upload could be avoided without how better control over the client's file choosing process.

-Peter

ALEX_GRIM · May 10th, 2005, 06:11 PM

where you say "CONTENT_LENGTH", how would you use that in a statement, eg. "request.httpCONTENT_LENGTH"? and i haven't yet found a way in asp.net to filter what file extentions are used like you can in vb. but then again, i haven't tried either.

---------------------------
A Black sheep moves easy in the darkness.
[email protected]
WWW.GRIMMUSIC.COM

planoie · May 10th, 2005, 09:35 PM

Request.ServerVariables("CONTENT_LENGTH")

There are also some server variables that are available as strongly typed properties of the Request class but I don't recall what they are off hand.

I'm not sure I understand what you mean by "...what file extensions...". Oh, do you mean when you click the browse button to choose the button for upload, you want to restrict it to a particular extension? I don't think you can do that because it's a feature of the browser (and therefore probably also the operating system) and thus not something you can control easily (if at all).

-Peter

ALEX_GRIM · May 10th, 2005, 10:30 PM

well thanks for the syntax example, i've seen it before, but i tend to not memorize things i don't think i'll need, and well, i was wrong about that one. so thanks.

---------------------------
A Black sheep moves easy in the darkness.
[email protected]
WWW.GRIMMUSIC.COM