GDI+ (GdiPlus) and ASP.NET

GDI (GdiPlus) and ASP.NET

DotNetKicks.com — Wed, 19 Mar 2008 19:33:01 GMT

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re: GDI+ (GdiPlus) and ASP.NET

Niki — Wed, 19 Mar 2008 21:59:29 GMT

So, what was the problem? I mean, some code must have allocated all that memory and never properly freed it. Is there a memory leak in GDI+? In GDI? In System.Drawing? Will it be fixed?? Or did the customer forget to call Dispose on some GDI+ objects?

re: GDI+ (GdiPlus) and ASP.NET

Tom — Wed, 19 Mar 2008 22:27:35 GMT

Yes, so in this case, something did allocated the memory. The problem is that sometimes you don't know when to clean these objects up and they end up staying around for a long time. In this case, something was holding onto the objects and keeping it from getting cleaned up.

It also could easily have been that they didn't clean up all the memory they allocated.

re: GDI+ (GdiPlus) and ASP.NET

Francois — Wed, 19 Mar 2008 22:43:38 GMT

That has always bothered me a bit... sure, System.Drawing isn't supported in certain senarios, and the documentation is incredibly clear on it...

however, what exactly is the alternative? Making my own image manipulation stack?

re: GDI+ (GdiPlus) and ASP.NET

Tom — Wed, 19 Mar 2008 22:50:19 GMT

For the scenarios where this is affected, there isn't really a good answer. System.Drawing assumes that it has an interactive user so it will try to show dialog boxes and things under some circumstances.

The best way is to test a lot and see what could go wrong and then handle those situation before it goes to System.Drawing so you don't have the problem. In this case, just making sure all objects get cleaned up will cut down the memory.

re: GDI+ (GdiPlus) and ASP.NET

Roger Martin — Thu, 20 Mar 2008 00:20:59 GMT

This has been driving me nuts as well. I run an open source gallery web app and sometimes the memory will continue increasing until it crashes. I've studied it to death to make sure I'm not missing any dispose calls.

Is it possible to improve things by forcing a garbage collection? I'm thinking the memory is locked so it won't get freed even during a forced collection. Grrr.

re: GDI+ (GdiPlus) and ASP.NET

Tom — Thu, 20 Mar 2008 06:42:40 GMT

I wouldn't suggest forcing a garbage collection. that won't really get you what you want. So there are a few things that you can do. Depending, you may want to create a case with Microsoft Support and have us help you track it down.

To create a case, check out:

http://blogs.msdn.com/tom/archive/2007/11/15/contacting-tom.aspx

There are a few things to look for. The easiest thing would be to make sure you aren't adding the objects to the cache or anything that would keep them rooted. You can use some of the High Memory posts here to try to track down the problem:

http://blogs.msdn.com/tom/archive/tags/High+Memory/default.aspx

re: GDI+ (GdiPlus) and ASP.NET

Josh Coswell — Thu, 20 Mar 2008 10:07:31 GMT

I think I have seen this type of behaviour of GDI in the past.

With this new insight I will have better chance to catch such problems.

Josh

http://riverasp.net

re: GDI+ (GdiPlus) and ASP.NET

Ostwald — Thu, 20 Mar 2008 17:12:28 GMT

Hey tom, I have a lil query in GDI . I want to extract the co-ordinates of the text from the image . I've already applied sobels algorithm and some morphing techniques. But i'm not gettint the exact coordinates so that i can draw a rectangle on that text. How can i do this?

re: GDI+ (GdiPlus) and ASP.NET

Tom — Thu, 20 Mar 2008 17:39:14 GMT

I am not an expert in GDI. I would suggest that you try asking this question on the forum or newsgroup for GDI. Like:

http://www.microsoft.com/communities/newsgroups/en-us/default.aspx?dg=microsoft.public.platformsdk.gdi&mid=27d0cbcb-9d41-4fbc-91ad-dec2fb7e7179

Or you can create a support case with Microsoft if you need the answer faster. See my comment above for how to create one.