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Hello community,
I just wanted to give a feedback, regarding to my question some days ago:My Question from 14. Sept[^]
There I was facing a Win32Exception, "Error creating window handle".
At this place I want to thank mav.northwind[^] for his great help!
He pointed me to the "User32.dll" method "GetGuiResources" (msdn documentation[^]),
which was exactly what I was looking for.
[DllImport("User32")]
extern public static int GetGuiResources(IntPtr hProcess, int uiFlags);
This method is able to return two values as you can see:
0 - Count of GDI objects: Is the one you also can watch over the taskmanager.
1 - Count of USER objects: Is not neccessary equal to the GDI Objects
and AFAIK not visible in the taskmanager.
An example, how the counting works:
If you place a UserControl on a form
1) a naked UserControl: GDI +1; User +1
2) a UserControl which holds a "PictureBox": GDI +1; User +2
3) a UserControl which holds a "System.Drawing.Pen": GDI +2; User +1
4) 2) + 3): GDI +3; User +2, ???
sometimes it returns: GDI +2; User +2, which would be expected)
I knew that there is a limit set in the Registry for the GDI Handle Quota (GDIProcessHandleQuota),
and there I also found one for the User Handle Quota (UserProcessHandleQuota).
Path: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Windows
NOTE: This limits are System limits, not process limits. Was not correct (Thanks to Robert Rohde)
So what I first did was doubleing the values from 10000 to 20000.
And what happens was nothing, no effect!
After a research I than found this very helpfull article[^] from Kristan Kenney
He points out that there are maximum acceptable limits for both values:
GDI max= 16384
User max= 18000
If you set the value over the limits the system will not work proper any more.
So I now did set the limits correct and my project worked again.
Now I wanted to find out how close I could come to the limits,
with my project blowing up a little.
I then scanned over all processes and found out,
that my project still crashes when the UserProcessHandles were about 13500 systemwide.
After rereading the Article from Kristan Kenney, I found an additional Registry setting which he also modified.
Path: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Session Manager\SubSystems
Key : Windows
This holds a long string with a section called: "SharedSection=1024,3072,512"
He modifies the second value of thees three (on my test PC there were four) to: "SharedSection=1024,8192,512"
I found a little explaination what this value does, at the msdn support[^]
The second SharedSection value (3072) is the size of the desktop heap for each desktop that is associated with the "interactive" window station WinSta0.
User objects like hooks, menus, strings, and windows consume memory in this desktop heap.
It is unlikely that you would ever need to change this second SharedSection value.
After this modification I was no longer facing crashes.
I'm now going over all my UserControls to find out which one can be modified.
Like, not using a PictureBox and painting the Bitmap in the OnPaint method of the UserControl.
Status from today: -1100 UserProcessHandles!
Hope someone can profit from that information!
Please correct me or give additional information.
-- modified at 9:00 Wednesday 19th September, 2007
All the best,
Martin
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Thanks for the information
Regards
DilipRam
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![Rose | [Rose]](https://codeproject.freetls.fastly.net/script/Forums/Images/rose.gif)
You are wellcome
All the best,
Martin
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Martin# wrote: NOTE: This limits are System limits, not process limits.
Are you sure about this one? Some time ago I was tracking down a leak of gdi handles and my app crashed when the number of gdi handles for it (watching the gdi handles column in the task manager) reached exactly 10000.
Robert
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Hello Robert,
You are 100% write!
Changed it!
I think its only the "SharedSection" which is a system limit.
Thank you for the correction!
All the best,
Martin
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Hello Dave,
Dave Kreskowiak wrote: You reall have to ask yourself, Why is the limit of window handles per process 10,000?[^]
The Short answere is:
Because the project needs it! 
I know that it's "a bad designed GUI" which commes to everybodys mind by reading my post.
But I think the application I'm working on is a little bit special.
It's is a GUI which does mainly control Process Variables (PV's) of an industrial machine.
It's about 20000 PV's (Input and Output) which have to be arranged.
Apart from that it has to do some graphical output, charts, ...
And the bad thing is, that the pages (UserControl with TabPages) allways have to stay in memory, because of fast reaction time at page change.
Good thing is, that the application runs nearly alon on an Industrial PC (XP embedded).
So I don't need to share the 32700 maximum of window manager objects.
Thanks for the link!
It provided some more information about that topic.
I'm allways open for suggestions regarding speeding up my application.
A big problem is also the time the system needs for the first painting of a Page.
Maybe you have some information about that.
Thanks again!
All the best,
Martin
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Martin# wrote: Because the project needs it!
No, it doesn't.
Martin# wrote: I know that it's "a bad designed GUI"
Yeah, it is. And this doesn't excuse it.
Martin# wrote: It's is a GUI which does mainly control Process Variables (PV's) of an industrial machine.
It's about 20000 PV's (Input and Output) which have to be arranged.
There are other ways of doing it beside trying to render 20,000 seperate windows. You can't come up with 20 applications that, COMBINED, use 20,000 handles.
Martin# wrote: Apart from that it has to do some graphical output, charts, ...
So what?? A single cached bitmap that you do your drawing on, then that gets repainted to the screen.
Martin# wrote: And the bad thing is, that the pages (UserControl with TabPages) allways have to stay in memory, because of fast reaction time at page change.
So you're telling me that you're storing your apps data in all the controls?? That's a REALLY bad idea and will do nothing other than cause you performance problems. The GUI (and all the controls that make it up) are there to show a visual representation of your apps internal data model. They do a terrible job of actually BEING the data model.
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Dave Kreskowiak wrote: Martin# wrote:
Because the project needs it!
No, it doesn't.
 Yes, it does
Dave Kreskowiak wrote: Martin# wrote:
I know that it's "a bad designed GUI"
Yeah, it is. And this doesn't excuse it.
Dave Kreskowiak wrote: Martin# wrote:
Apart from that it has to do some graphical output, charts, ...
So what?? A single cached bitmap that you do your drawing on, then that gets repainted to the screen.
So nothing! Just wanted to say that apart from >6000 output and input boxes and labels, there are other controls handling some tasks. In fact we are using ZedGraph Control (about 20-30).
Dave Kreskowiak wrote: Martin# wrote:
And the bad thing is, that the pages (UserControl with TabPages) allways have to stay in memory, because of fast reaction time at page change.
So you're telling me that you're storing your apps data in all the controls??
No, not even when I reread my sentence I would come to that idea!
I have the feeling you have are lacking of sleep!
We just hold the pages in memory, couse the instanciating of the page during runtime (page change) would take too much time.
All the best,
Martin
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Martin# wrote: I have the feeling you have are lacking of sleep!
Guy, you have no idea how true this is.
I used to work for a major automaker, and I've seen and supported some huge plant floor control systems that blew my mind in their complexity. But in no case, have I ever seen anything approaching a couple thousand handles, let alone 10's of thousands.
There is no reason to have a page full of label controls to show data when your code can be rewritten to paint all the data itself on a single page.
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Hello Dave,
Dave Kreskowiak wrote: Guy, you have no idea how true this is.
I'm happy, that you keeped your humor.
Dave Kreskowiak wrote: I used to work for a major automaker, and I've seen and supported some huge plant floor control systems that blew my mind in their complexity.
And thats the point:
You are talking of an application for one task (also if it's a very hughe task).
My project needs to fit with all machines our company produces (about 500 per year).
They are not all different of course but they differe in some points, sometimes more sometimes less.
That means we need a high dynamic GUI, which has to be handled from about 15 people from all over the world.
Dave Kreskowiak wrote: There is no reason to have a page full of label controls to show data when your code can be rewritten to paint all the data itself on a single page.
This is simply not possible for our project!
As the controls provide some userdefined Binding mechanism (sometimes a control is binded to 5 - 10) different PV's, which tells the control for example if an option is set or not.
An other reason is that there is a feature where a user of the GUI is able to build his own page by "grapping" controls (plus all bindings) from existing pages, and insert it in his own page.
All the best,
Martin
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All I can do is smile. Have fun with it!
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Hi Martin!
Great, fine you got it to work.
You could make an article out of this, so that the information can be found more easily. I guess it could be useful for many developers...
Regards,
mav
--
Black holes are the places where God divided by 0...
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Hello mav,
Thanks for youre nice words!
mav.northwind wrote: You could make an article out of this, so that the information can be found more easily. I guess it could be useful for many developers...
Good idea!
Hmm, maybe when I do some more research.
All the best,
Martin
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Hi,
I have 5 rows in my datagridview1. but how to remove any particular row?
when I use => "dataGridview1.Rows.RemoveAt(4)" then error comes "Uncommited new row cannot be deleted". 
Thank you in advance
-- modified at 3:22 Wednesday 19th September, 2007
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hello dear,
try it
string dgvstr="";
SqlDataAdapter da = new SqlDataAdapter("select (enter all columan_name in table) from table_name", con);
dgvstr = da.SelectCommand.CommandText.Replace(",enter remove columan_name", "");
DataSet ds = new DataSet();
da.Fill(ds, "table_name");
datagridview.DataSource = ds.Tables[0];
datagridview.Columns[enter remove column_index(ex-0)].Visible = false;
datagridview.Rows[0].Selected = true;
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datagridview1.currentrow.cell(0).value
this will work and give the connection
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Hi
I've to transmit live video 4m Server to multiClients and I m working in C# and using UDP. Now plz tell me what steps I should follow 4 transmission of live video?
How would I stream the video.I m not getting help in this matter from net so plz help me out.
Shanzay
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How we will create usercontrol for tablelayoutpanel in c#windows application?
for other controls like button,label i creatd but i am not able to create for container controls like tabcontrol,tablelayoutpanel.i want usercontrol not customcontrol
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Hey
I am not sure I fully understand you question here but I will answer what I think you mean.
All you do is drag the control (eg tab contronl) onto a windows form then place you components onto with the relevant tab selected.
Hope this helps
Dan
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Thanks for ur Reply
can u make usercontrol using tablelayoytpanel?
and how do we make row,columns in table lay out
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Hey
It sounds like a typical grid control might offer what you are looking for?
If not explain exactly what it is you need and I will have a look around for you. Remember Google is your friend.
Dan
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hi friend
user control shall be use by single appllication and custom control is used by multiplication application
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Uh, that's nowhere near correct.
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Inheriting from UserControl is normally used to build "compsite controls" where you use a few controls, like you would use on a form, to build a custom control that encompasses those controls with a related purpose. For instance, creating a custom IPv4 Address Entry control using 4 seperate TextBox controls.
Inheriting from Control allows you to build a completely custom control from the ground up. You supply everything from properties, to data management, to all the rendering code.
There's a thrid option. Inheriting from an existing control, like a Button or TableLayoutPanel. This gives you the ability to create your own customized version of that control where you add to, hide, or replace some the functionality of that existing control.
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