Feedback: How to find the number of current window handles [modified] - C# Discussion Boards

garyshort18-Sep-07 23:12

18-Sep-07 23:12

Provided there is no limit placed by the programmer on the ArrayList size then - since ArrayLists hold objects (value types are boxed) - the capacity of your ArrayList is governed by the size and number of objects you are holding, which in turn is governed by the heap size of your computer.

--
Cheers,
Gary
http://www.garyshort.org

Re: Max member of ArrayList?

Dave Kreskowiak19-Sep-07 5:17

Dave Kreskowiak

19-Sep-07 5:17

The limits are int.MaxValue items or when you get an OutOfMemory exception, whichever comes first.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

Socket Connection, help me please!!!!

Vampire1986hieu18-Sep-07 21:47

Vampire1986hieu

18-Sep-07 21:47

I've a project about socket and have some trouble....
I've create a serverSocket on port 80 of a server : (IPserver,80)
And then create a clientSocket on port 80 of some clients: (IPclients,80)
So i need a code to do
First I've created a serverSocket and listening communicate from clientSocket (done)
Second I need a code on clientSocket to do
0. Create clientSocket
1. Connect to serverSocket
2. To do something..
3. Disconnect
4. Sleep and wait
5. Connect to serverSocket
6. To do something..
7. Disconnect
8. Destroy clientSocket
I don't know how to code method Create clientSocket, method Connect to serverSocket, method Disconnect.
Anyway thanks for your reply

Le Trung Hieu

Re: Socket Connection, help me please!!!!

garyshort18-Sep-07 23:15

garyshort

18-Sep-07 23:15

You should start off by examining the System.Net namespace in the .Net framework. Then if you have a specific question post it here.

--
Cheers,
Gary
http://www.garyshort.org

Re: Socket Connection, help me please!!!!

ramdil19-Sep-07 0:32

ramdil

19-Sep-07 0:32

Hi
create two ports which should be available in network
one is for listening and one is for recieving
that means listner port will be the receiver port in another side
and vice versa
then inside the listen method use the start method and send method
inside the reciever method use the start method and recieve method of socket
..after that use stop method or close method in connectin close
Hope u have got some fair idea from this.Lots of examples are their in code project...

Regards
DilipRam

Re: Socket Connection, help me please!!!!

Vampire1986hieu20-Sep-07 16:11

Vampire1986hieu

20-Sep-07 16:11

Thanks for your help.
But I only use one port(80).

Le Trung Hieu

Help on pinvoke functions

izakfick18-Sep-07 21:43

izakfick

18-Sep-07 21:43

hi, does anyone know how to obtain text from an external application's editor. I've used some Pinvoke functions to obtain the main window handle, then enumChildWnd to find the relevant class handle that the editor derives from. Now my question is. now that I've got the handle.. what do i need to do to read the text from the editor. I'm not trying to get any Window handle by using the windowtext function.. Ideally i would want to read all text or be able to read by line where the caret is located. If anyone could point me in the right direction I would appreciate it.

The App I'm hooking into is SQL Server Management Studio, the editor used by SQmgntStudio is called VsTextEditorPane..

Regards
Izak Fick

Feedback: How to find the number of current window handles [modified]

Martin#18-Sep-07 21:27

Martin#

18-Sep-07 21:27

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.

/// uiFlags: 0 - Count of GDI objects
/// uiFlags: 1 - Count of USER objects
/// - Win32 GDI objects (pens, brushes, fonts, palettes, regions, device contexts, bitmap headers)
/// - Win32 USER objects:
/// - WIN32 resources (accelerator tables, bitmap resources, dialog box templates, font resources,
///   menu resources, raw data resources, string table entries, message table entries, cursors/icons)
/// - Other USER objects (windows, menus)
[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

Re: Feedback: How to find the number of current window handles

ramdil19-Sep-07 0:33

ramdil

19-Sep-07 0:33

Thanks for the information

Regards
DilipRam

Re: Feedback: How to find the number of current window handles

Martin#19-Sep-07 2:16

Martin#

19-Sep-07 2:16

You are wellcome

All the best,

Martin

Re: Feedback: How to find the number of current window handles

Robert Rohde19-Sep-07 2:53

Robert Rohde

19-Sep-07 2:53

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

Re: Feedback: How to find the number of current window handles

Martin#19-Sep-07 3:04

Martin#

19-Sep-07 3:04

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

Re: Feedback: How to find the number of current window handles

Dave Kreskowiak19-Sep-07 5:28

Dave Kreskowiak

19-Sep-07 5:28

You reall have to ask yourself, Why is the limit of window handles per process 10,000?[^]

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

Re: Feedback: How to find the number of current window handles

Martin#19-Sep-07 8:17

Martin#

19-Sep-07 8:17

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! Wink | ;)

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

Re: Feedback: How to find the number of current window handles

Dave Kreskowiak19-Sep-07 12:04

Dave Kreskowiak

19-Sep-07 12:04

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.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

Re: Feedback: How to find the number of current window handles

Martin#19-Sep-07 19:33

Martin#

19-Sep-07 19:33

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! Wink | ;)

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

Re: Feedback: How to find the number of current window handles

Dave Kreskowiak20-Sep-07 1:59

Dave Kreskowiak

20-Sep-07 1:59

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.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

Re: Feedback: How to find the number of current window handles

Martin#20-Sep-07 2:48

Martin#

20-Sep-07 2:48

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

Re: Feedback: How to find the number of current window handles

Dave Kreskowiak20-Sep-07 12:35

Dave Kreskowiak

20-Sep-07 12:35

All I can do is smile. Have fun with it!

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

Re: Feedback: How to find the number of current window handles

mav.northwind19-Sep-07 19:07

mav.northwind

19-Sep-07 19:07

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...

Re: Feedback: How to find the number of current window handles

Martin#19-Sep-07 19:35

Martin#

19-Sep-07 19:35

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

Remove One Row from DataGridView [modified]

M Riaz Bashir18-Sep-07 21:15

M Riaz Bashir

18-Sep-07 21:15

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". Frown | :(

Thank you in advance

-- modified at 3:22 Wednesday 19th September, 2007

Re: Remove One Row from DataGridView

sri_ashutosh18-Sep-07 21:53

sri_ashutosh

18-Sep-07 21:53

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;

Re: Remove One Row from DataGridView

rohitsrivastava19-Sep-07 0:00

rohitsrivastava

19-Sep-07 0:00

datagridview1.currentrow.cell(0).value

this will work and give the connection

Live Video Transmission

DeepOceans18-Sep-07 20:41

DeepOceans

18-Sep-07 20:41

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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