Memory Leak in IE WebBrowser Control

Question

Ok, I hope this is the correct place to ask this question!

I originally asked this question in the C# Development forum:
http://forums.microsoft.com/MSDN/ShowForum.aspx?ForumID=8&SiteID=1
but one of the moderators informed me that I needed to ask it in the
IE Discussion Group
but one of the moderators there told me that I need to ask it in THIS forum!
Here is my question:

This appears to be a common problem, but so far I have not found any answers
to it.

I am building a C# application with an IE WebBrowser control in it.
Whenever I navigate within a page I've loaded in the control, large amounts
of memory are being used and not released. After 7 hours of use, my app was
showing a memory use of 900MB, which is simply unacceptable for my clients.

My question (for myself and all the others who have asked it) is: how can we
release the memory being used by the WebBrowser control without completely
shutting down the application? I have tried removing the WebBrowser control
from it's parent form and calling the dispose() Method on it, but the memory
is not released. I have confirmed the memory leak/usage with Taskmgr.exe,
Perfmon.exe, and Process Explorer, all of which show this abnormally high
memory usage.

I understand that the memory usage might come in part from circular
references in the underlying DOM object, but I need a way to manually free
this memory from time to time.

If this is in no way possible, then what alternatives do developers have
(seeing as this memory consumption is not acceptable to many of us)?

I would really appreciate it, and think it would be great if we can finally
resolve this issue! Thank you so much for your assistance!

Again, I apologize if this is the wrong forum, but I was informed
that this was the place to post this!  Thanks again!

Answer 1

What I do is to spawn off a web browser automating program, passing an id via command line. The program reads additional request information from a database based on the id and writes automating result to the database row identified by the id, then exits. 

Answer 2

I'm not quite sure how this answers my question.  I'm probably just missing something; sorry!

Answer 3

Aren't you asking for alternatives?

Answer 4

Ok, I understand what you are saying now; thank you for the suggestion!  However, if many operations are being done on a particular HTML document at regular intervals, it isn't very practical for me to spawn new apps constantly.

If there is no way to deal with the memory leak in the IE control, I am looking for alternatives to the IE WebBrowser control itself.

Thanks in advance for your help!

Answer 5

You will thank me for ever for this solution -

I had couple of application using web browser control and these windows would contineously load new pages. Every time new page loads the application will consume about 5mb memory and would never release it. That would cause the the meory use to go above 1.5 gb in short time causing the application to run slow and finally crash just after couple hours.

The culprit is IE7. It had severe memory leak issues.

Solution - Install new browser IE8. All memory leaks plugged. application do not consume any more memory, runs smoothly for hours without crashing

 

Ajit

 

Answer 6

 

You can try to navigate to about:blank and next back to the page. In my case a memory ocupied by the IE control will be freed.

Answer 7

Thank you both for the suggestions!  Unfortunately, I am still in the same position; memory is being consumed and never released.  I have updated to IE8 and tried navigating to an about:blank page to no avail.

Answer 8

Is the memory released when you minimize the app ? If so, try this:

-- in class definition

        [DllImport("KERNEL32.DLL", EntryPoint = "SetProcessWorkingSetSize", SetLastError = true, CallingConvention = CallingConvention.StdCall)]
        internal static extern bool SetProcessWorkingSetSize(IntPtr pProcess, int dwMinimumWorkingSetSize, int dwMaximumWorkingSetSize);

        [DllImport("KERNEL32.DLL", EntryPoint = "GetCurrentProcess", SetLastError = true, CallingConvention = CallingConvention.StdCall)]
        internal static extern IntPtr GetCurrentProcess();

-- code to call when you want to reduce the memory

            IntPtr pHandle = GetCurrentProcess();
            SetProcessWorkingSetSize(pHandle, -1, -1);

Answer 9

 I've got the same issue and have for a long time.  After the web browser control is used for a while the memory keeps growing and never releases.  Collecting the garbage doesn't work, things are disposed of properly, minimizing the window doesn't work.. the only thing that fixes it is to restart the application.  It will continue to grow until the application crashes.  I haven't found any solutions for this as of yet. 

Answer 10

I am having the same issue and I haven't been able to find a solution anywhere. Could be that the WebBrowser control is just cursed to be a memory leaking hog. =( Has anyone found a solution or an alternative control based on another browser?

Thanks in advance...

---

Gnom3

Answer 11

I have the same problem, I try to do everything but VM / Memory Size keeping growing

wb .Dispose();

wb = null;

GC.Collect();

GC.WaitForPendingFinalizers();

GC.Collect();

Can someone please give us a hint to solve the problem.

Answer 12

Hello,

I have this problem too.
try this page : http://support.microsoft.com/kb/896663
or this page too : http://support.microsoft.com/kb/943510/
may be can help you.

best regards

Answer 13

I can't believe there's no solution to this browser control memory leak issue.  I'm having the same problem and have found no solutions online.  The only choice is to restart the entire process every so often.  Which is soooo 1990's.

I tried all the GC techniques, which doesn't do anything for the unmanaged memory leak coming from the underlying ActiveX component.  Also tried creating AppDomains to host the browser control.  AppDomains don't seem to separate out the unmanaged memory.  They all share the same pool, which when exited, leaves the leaked memory unchanged.  

Ugghhhhhhh.  This is way dumb.

Anyone else have any suggestions?

Answer 14

This solution worked for me!!
Thank you so much mike_t2e!!!!!!!

-----------------------------------------------------------------------

Is the memory released when you minimize the app ? If so, try this:

-- in class definition

        [DllImport("KERNEL32.DLL", EntryPoint = "SetProcessWorkingSetSize", SetLastError = true, CallingConvention = CallingConvention.StdCall)]
        internal static extern bool SetProcessWorkingSetSize(IntPtr pProcess, int dwMinimumWorkingSetSize, int dwMaximumWorkingSetSize);

        [DllImport("KERNEL32.DLL", EntryPoint = "GetCurrentProcess", SetLastError = true, CallingConvention = CallingConvention.StdCall)]
        internal static extern IntPtr GetCurrentProcess();

-- code to call when you want to reduce the memory

            IntPtr pHandle = GetCurrentProcess();
            SetProcessWorkingSetSize(pHandle, -1, -1);

Answer 15

Thanks, mike_t2e!  Your solution helped me very much!

Answer 16

SetProcessWorkingSetSize doesn't actually release any memory. It does incease the probabilty of the memory being paged out to disk, and probably cause a GC collect.

Memory leaks like circular reference of javascript objects may not be affected though. Until IE7, IE does not break circular reference automatically.

---

MSMVP VC++

Answer 17

Please DO NOT use script manager and update panel , they have memory leak

Answer 18

SetProcessWorkingSetSize doesn't actually release any memory. It does incease the probabilty of the memory being paged out to disk, and probably cause a GC collect.

Memory leaks like circular reference of javascript objects may not be affected though. Until IE7, IE does not break circular reference automatically.

---

MSMVP VC++

This is true... SetProcessWorkingSetSize doesn't release any memory.
I don't understand background workings of WebBrowser control, but I realised one thing:
My program goes through 500 or more pages and reads new content on them. It hogs the RAM quite quickly, and if I run the same function that runs through all those pages again, it simply reads from webbrowser cache, cause it needs only couple of seconds to complete.
It means that we only need to clear browser cache in order to free RAM. Right? I found this solution, but it doesn't work.

http://support.microsoft.com/kb/326201/en-us

It allways gives me PrtectedMemoryException..
Ok, so how is it possible that the memory is freed only when I close my application, and it's not freed when i dispose my webbrowser control and create new one?

Answer 19

Dispose isn't necessary freeing memory. It merely tells the COM server you do not hold the object anymore. The COM server is free to decide when to free memory (e.g. when gc collect or cache expire or wininet session clear)

---

---

The following is signature, not part of post
Please mark the post answered your question as the answer, and mark other helpful posts as helpful, so they will appear differently to other users who are visiting your thread for the same problem.
Visual C++ MVP

Answer 20

(reposted here, edited)

I still have the problem having tried all the fixes here - including using subtasks. Web pages are now becoming so loaded with script the granularity of individual subtasks is becoming an issue. On at least two critical sites memory consumption is so dire I need a better fix. Bad sites can leak around 1Mb per page so after ~2000 pages a 32-bit process is consuming >2Gb and fails.

Switching off script cures the leaks but breaks some sites. IE8 still has the problem despite the fixes here:
  http://msdn.microsoft.com/en-us/library/dd361842%28VS.85%29.aspx
In some cases I may be able to change the site script. Does anyone have similar examples of what the site authors should still avoid?

Is there anything else I can try?

Will IE9 make further improvements to garbage collection? Might this fix the issue or should I assume not?

Thanks!
R.

Answer 21

Same here. It became even worse with IE7 and IE8. I found out that the Solution with something like:

SetProcessWorkingSetSize(pi.hProcess, (SIZE_T)-1, (SIZE_T)-1))

does it for a while, when I do it every 20 navigations.

Then when the Pagefile-Usage is above a certain limit the application is restarted completely rather fast, so it is freed again.

Sad story is, that it is in an MFC-CHtmlView, already filled with correction-code from a dozen KB's and the whole app is many years old.

I hope this horror is soon being solved, on the long run it is getting embarassing to sell software that is based on CHtmlView or WebBrowser2. I got the same problems with doing it with WTL/ATL. After an intensive debugging it is provable, that it happens in Navigate/Navigate2.

If there is any solution: please, please, please!

Answer 22

We are now 15 07 2010 . Is there already a solution for this problem?

This bug prevents developers to make a professional application with this control.

It's so strange Microsoft can't find an aswser for this?

Peter Adriaenssens

 

 

Answer 23

I met this problem also, and I found that if I minimize the window, the memory will decrease immediately. So I periodically minimize the dialog.

Answer 24

That is the same like

SetProcessWorkingSetSize(pi.hProcess, (SIZE_T)-1, (SIZE_T)-1))

and it also only works correctly on Windows without DirectX-Desktop (pre-vista/7).

In the meantime we redeveloped the thing with OLE/COM in pure platform-sdk-windows-C-code and removed any framework around. Strangely now it works and doesn't leak anymore. I assume now it is inside MFC and WTL where the wrappers are initialized or the surrounding code for Navigate(2) is called.

This whole thing is like proving the Fermat-equations :-) Seems like it goes over years and years.

Answer 25

There is a known memory leak in the WebBrowser control.  See the following Microsoft KB article - KB893629

Hope this helps!  If you find this post as helpful, please mark it as such.

---

If this post is helpful, please mark it as such!
Dave Black, MCPD, MCTS
http://dave-black.blogspot.com

Answer 26

    public void SetSelectedCorridor(string value)
    {
      JavaScriptFun("SelectStationList", value);
      JavaScriptFun("SetStationOption", value);
    }

    public object JavaScriptFun(string funName, params object[] args)
    {
      return bFT.Document.InvokeScript(funName, args);
    }

After calling SetSelectedCorridor, the WebBrowser control leaks memory at a rate of about 1 KB/sec.

The same thing happens when I use an option list input on the page that calls "SelectStationList" when the selected option changes.
This problem does not happen when the page is loaded in IE 8.

I have XP service pack 3 so I don't think the KB893629 applies. SP3 applies this patch.

The one workaround I have found that works is to call webBrowser1.Stop(); after my JavaScript is runs. I invoke a timer handler to run Stop so that
the page refresh has time to complete before the Stop is called.

Any idea why my scripts start a constant slow memory leak when running in the WebBrowser control?

Answer 27

I am a little bit new here, but already found a lot of help.

And also in this post, thanks, thanks!

---

IE Prof
Martijn de Ruiter
http://www.dehorecaopkoper.nl

Answer 28

June 2011, IE 9 installed. Still having the problem. 

Yeahhhhhhhhhhhhhhhhhhhh!

Answer 29

Thank you very much, this solution work OK in my app.

 

Answer 30

This worked for me mike_t2e. Thanks for your solution.

Answer 31

mike_t2e thanks very much that does seem to clear away some of the cruft.

As other have indicated it's not a complete solutions but stymies the tide a little.

I suppose I will have to consider Shengs workarounds in the long term....

This issue has been on the card for Years and Years now... Ah well.

Thank for the little help. it helped.

---

I came, I saw, I coded

Answer 32

Depending on a person's particular machine, I believe there are two separate issues going on here. First, as several people pointed out, there is a known memory leak in IE7. However, I am running IE8 on Windows 7 64-bit and notice similar but different behavior.

In my case, when I close my application that has the WebBrowser control, the memory does get released. By definition, a memory leak can't get released without actually rebooting your computer. So the similar phenomenon that is happening with newer versions of IE is not a memory leak. Rather, I would point the finger at .NET's black box garbage collector for being too slow and not recognizing when memory can be release.

I've read a number of posts that suggest a range of success/failure in using manual calls to GC to release memory. I'm still looking into this. But my main point was not to assume its a memory leak just because huge chunks of memory are getting used up. First check to see if that memory gets released when you shut down your application.

Answer 33

In my case, when I close my application that has the WebBrowser control, the memory does get released. By definition, a memory leak can't get released without actually rebooting your computer. So the similar phenomenon that is happening with newer versions of IE is not a memory leak. Rather, I would point the finger at .NET's black box garbage collector for being too slow and not recognizing when memory can be release.

That must belong somewhere else.

1) We are talking about native, non-.NET- Applications here.

2) Assuming a windows-platform that can run IE7/IE8: A memory-leakage that is occuring in the storage-region belonging to a certain process is also gone, when that process is gone. Proof that such stuff applies to IWebBrowser2-related things is here: IWebBrowser2's memory not deallocated

I still think it is in MFC/WTL, because after rewriting the application, so that it NOT uses it, we didn't have the effect anymore.

Answer 34

I had luck with mikes solution coupled with a deconstruction of the controls and disposal of the control before the form is disposed:

//main form

bool firstTime = true;

            //to test memory leak in a loop create my flash video player embedded in a web browser control on a winform
            while (firstTime || chkContinuousTesting.Checked) {
                firstTime = false;


                string fileName = @"C:\Personal\MPV\TestVideo\Videos\20051210-w50s.flv";
                FormVideoPlayer frm = new FormVideoPlayer();
                frm.Play(fileName);
                frm.ShowDialog(this);
                frm.Dispose();
                frm = null;


                //cleanup to take care of WebBrowser memory leak
                Win32.MinimizeRelease();
            }

//on close event from video player form

private void FormVideoPlayer_FormClosing(object sender, FormClosingEventArgs e) {

            this.Hide();


            //help to clean up web browser memory leak
            webBrowser1.Stop();


            this.SuspendLayout();

            webBrowser1.PreviewKeyDown -= new System.Windows.Forms.PreviewKeyDownEventHandler(this.webBrowser1_PreviewKeyDown); //unregister any events to prevent memory leak
            this.Controls.Remove(this.webBrowser1); //remove the control
            this.ResumeLayout(false);


            webBrowser1.Dispose(); //dispose the control
            webBrowser1 = null;            
        }

//Win32 Class

using System;             //Required for Win32Exception
using System.Runtime.InteropServices;    //Required for DllImport, IntPtr ...
using System.ComponentModel;


namespace TestVideo {
    public class Win32 {

#region Minimize, Memory Release

        [DllImport("KERNEL32.DLL", EntryPoint = "SetProcessWorkingSetSize", SetLastError = true, CallingConvention = CallingConvention.StdCall)]
        internal static extern bool SetProcessWorkingSetSize(IntPtr pProcess, int dwMinimumWorkingSetSize, int dwMaximumWorkingSetSize);


        [DllImport("KERNEL32.DLL", EntryPoint = "GetCurrentProcess", SetLastError = true, CallingConvention = CallingConvention.StdCall)]
        internal static extern IntPtr GetCurrentProcess();


        public static void MinimizeRelease() {
            IntPtr pHandle = GetCurrentProcess();
            SetProcessWorkingSetSize(pHandle, -1, -1);


            GC.Collect();
            GC.WaitForPendingFinalizers();
            GC.Collect();

      }
        #endregion
    }
}

After this fix I ran for many hours without seeing any memory increasing.

Jason

Answer 35

It is sad to see that there is no working solution yet to this issue.

Seems that nobody from Microsoft bothered to create a fix for this control.

Has anyone tried other controls as alternatives in a commercial application.

Maybe:

http://code.google.com/p/geckofx/

http://webkitdotnet.sourceforge.net/

http://awesomiumdotnet.codeplex.com/

http://code.google.com/p/open-webkit-sharp/

Any thoughts?

Thx,

Daniel

---

-Creator-

Answer 36

Has anyone tried any of those WebBrowser components?

IE webBrowser is useless for my purpose, hoping someone would light my path with an alternative.

Daniel

---

-Creator-

Answer 37

o_O

Mike! its Works, very impressive.

I'm working on an application that uses a webbrowser, I have several tabs in the main html, and whenever sailing including memory increased.

Now by using this code between the navigation memory is freed.

Very very thanks!

---

SifriG

Answer 38

Daniel:

As I wrote before, you can use the IWebbrowser2 directly, without a framework. This might be taking some time and for my case I had to rewrite the whole applications GUI. But ... It worked.

BTW: I retested the problem with the MFC GUI in CHtmlView with VC11 and it still occurs.