DataGrid ??? - C# Discussion Boards

Senkwe Chanda11-Nov-02 3:20

11-Nov-02 3:20

Anybody know how to go about getting a handle to the default windows cursor?

Cursors.Arrow.Handle returns what seems to be a valid handle, but I get an error when I call

InPtr Hicon = Cursors.Arrow.Handle;<br />
<br />
Bitmap tempBitmap = Bitmap.FromHicon(Hicon);

The error is "invalid parameter used"

\\winnt\cursors doesn't seem to contain the actual default arrow cursor as a ".cur" file. It's defined in winuser.h via MAKEINTRESOURCE(...) with the identifier IDC_ARROW.

I wouldn't mind going the unmanaged route. (I'm doing this in fact, but using a cursor in the \\winnt\cursors directory). But that's just a temp solution as I really want the default cursor. How would I define Win32's LoadImage(...) or indeed the LoadCursor(...) function with regards to the MAKEINTRESOURCE(...) call?

Gosh, what an ugly question eh?

Smile | :)

ASP.NET can never fail as working with it is like fitting bras to supermodels - it's one pleasure after the next - David Wulff

Re: idc_arrow and C#

Stephane Rodriguez.11-Nov-02 4:01

Stephane Rodriguez.

11-Nov-02 4:01

Senkwe Chanda wrote:
InPtr Hicon = Cursors.Arrow.Handle;

This IntPtr is actually a WIN32 HCURSOR, not a WIN32 HICON, hence the error.

Back to real work : D-19.

Re: idc_arrow and C#

Senkwe Chanda11-Nov-02 5:12

Senkwe Chanda

11-Nov-02 5:12

Thanks .S.Rod. I'm used to using them interchangably via win32. Do you have any ideas on how I can get access to the handle for the default windows cursor? IDC_ARROW?

ASP.NET can never fail as working with it is like fitting bras to supermodels - it's one pleasure after the next - David Wulff

Re: idc_arrow and C#

Stephane Rodriguez.11-Nov-02 5:13

Stephane Rodriguez.

11-Nov-02 5:13

Senkwe Chanda wrote:
Do you have any ideas on how I can get access to the handle for the default windows cursor?

Doing Cursors.Arrow.Handle is the right code (internally it does a simple ::LoadCursor(IDC_CURSOR);

But, as I have already said, this call returns a HCURSOR.

What you were trying to do next is build a bitmap. That's a fine idea, but the API method you use expects an HICON, not an HCURSOR.

So you've got to find somewhere (either in the .NET API, or through WIN32) a way to convert the HCURSOR to an HICON. I guess that if that was only a matter of casting, this would not lead to an error.

What about lurking around Codeproject articles dealing with HCURSOR and HICON ?

Back to real work : D-19.

Re: idc_arrow and C#

Senkwe Chanda11-Nov-02 19:39

Senkwe Chanda

11-Nov-02 19:39

Believe me .S.Rod, I've tried and come up blank Smile | :)

The easiest way (or the only way I can find) is to do it via Win32. That's ok except that I have no clue as to how to define the IDC_ARROW identifier in my .NET code. I couldn't find any articles on the topic. But thanks anyway. Perhaps I'll try and be content with my little hack Smile | :)

Cheers

Senkwe

ASP.NET can never fail as working with it is like fitting bras to supermodels - it's one pleasure after the next - David Wulff

Re: idc_arrow and C#

Anonymous11-Nov-02 19:56

Anonymous

11-Nov-02 19:56

Senkwe Chanda wrote:
That's ok except that I have no clue as to how to define the IDC_ARROW identifier in my .NET code.

public const int IDC_ARROW = 32512; // from winuser.h

Re: idc_arrow and C#

Senkwe Chanda11-Nov-02 20:47

Senkwe Chanda

11-Nov-02 20:47

Hi there, thanks, I'm aware of that Smile | :)

It's using it that's a problem right now.

Cheers

Senkwe

ASP.NET can never fail as working with it is like fitting bras to supermodels - it's one pleasure after the next - David Wulff

DataGrid ???

Christian Graus11-Nov-02 1:05

Christian Graus

11-Nov-02 1:05

I have been playing with ADO.NET and my connection object returns me a OleDbDataReader. How do I turn that into something I can bind to the DataGrid ?

Thanks for any suggestions.

Christian

No offense, but I don't really want to encourage the creation of another VB developer. - Larry Antram 22 Oct 2002

Hey, at least Logo had, at it's inception, a mechanical turtle. VB has always lacked even that... - Shog9 04-09-2002

During last 10 years, with invention of VB and similar programming environments, every ill-educated moron became able to develop software. - Alex E. - 12-Sept-2002

Re: DataGrid ???

James T. Johnson11-Nov-02 4:00

James T. Johnson

11-Nov-02 4:00

Use the DataAdapter's Fill method to fill a DataSet then set the DataSource property of the grid to the DataSet you just filled.

~~[edit]Sorry its early, i'll get back with you on how to do it [/edit]~~

It pays if I look at the right class in the framework, use the OleDataAdapter class, passing in your OleDbCommand object; then use one of the Fill methods.

James

- out of order -

Re: DataGrid ???

leppie11-Nov-02 7:27

leppie

11-Nov-02 7:27

Hi
To add the James's response, the DBAdapter has a wonderfull Configure button Smile | :)

Takes care of almost everything, but you mite need to modify the statements or procudures to your liking.

DataSets are really good timesavers Smile | :)

, but there is a performance overhead (not that its really noticable on my PC anyways)

Cheers Smile | :)

"I dont have a life, I have a program."

.NET Training Institute

ReachAnshul10-Nov-02 20:30

ReachAnshul

10-Nov-02 20:30

Hi Guys,
I am looking for .NET training institute in bay area (Sunnywale,Santa clara or Fremont).
Please let me know if you know one.
Thanks
Anshul

Re: .NET Training Institute

Christian Graus10-Nov-02 20:43

Christian Graus

10-Nov-02 20:43

Several people at work have done .NET courses. My advice - buy Programming the .NET Framework, Inside C#, and the ADO.NET and ASP.NET books from Microsoft. You'll learn more and it will cost less.

Christian

No offense, but I don't really want to encourage the creation of another VB developer. - Larry Antram 22 Oct 2002

Hey, at least Logo had, at it's inception, a mechanical turtle. VB has always lacked even that... - Shog9 04-09-2002

During last 10 years, with invention of VB and similar programming environments, every ill-educated moron became able to develop software. - Alex E. - 12-Sept-2002

BindingsCollection

Alan Todtenkopf9-Nov-02 12:19

Alan Todtenkopf

9-Nov-02 12:19

I am unsuccessful in inheriting from this class. ControlBindingsCollection inherits from it and it has protected internal members implying it was designed to be inherited from. Yet, the compiler says there is no access to the constructor and the object browser does not show a constructor.

Alan

Re: BindingsCollection

James T. Johnson9-Nov-02 12:25

James T. Johnson

9-Nov-02 12:25

Shawn Wildermuth *just* answered your question, but I'll repost it here for those not on the DOTNET-WINFORMS[^] mailing list.

"The constructor is marked internal...that's how the ControlBindingsCollection inherits from it."

James

- out of order -

Downloading files with Webrequest

Anonymous9-Nov-02 8:40

Anonymous

9-Nov-02 8:40

How do I determine when to stop reading from the response stream on a webrequest? It seems that if I do
while (bytesread > 0)
bytesread = bufferedrdr.Read(buffer, 0, buffer.Length);

I'll get incomplete files. Looks like the stream returns 0 bytes read whenever the internet connection lags. Most of the example code does use a 0/-1 return code to determine when to stop reading.

The read method doesn't wait until there is new data in the stream does it? Confused as to how to determine when the end of the file is downloaded.

Re: Downloading files with Webrequest

Stephane Rodriguez.9-Nov-02 9:10

Stephane Rodriguez.

9-Nov-02 9:10

It uses an asynchronous callback system. More info here[^].

Back to real work : D-21.

Re: Downloading files with Webrequest

Anonymous9-Nov-02 10:17

Anonymous

9-Nov-02 10:17

Is there any adavantage of using begininvoke/endinvoke? I already have each download running in a seperate thread.

Re: Downloading files with Webrequest

Stephane Rodriguez.9-Nov-02 10:25

Stephane Rodriguez.

9-Nov-02 10:25

Anonymous wrote:
Is there any adavantage of using begininvoke/endinvoke?

I am afraid not since that's what is done already. By the way, you should also know that the underlying connection is multi-threaded too (with an upperbound I can't remember at the moment).
I believe the only way to cope with the problem you are facing is to write your own httpweb request stuff. The funny thing is the http web request itself is bad only because it doesn't provide configuration capabilities over the underlying connection. There is a lot of application logic underneath.
Which is equivalent to say the people at MS who created it thought developers were ready to do web requesting on a fire and forget basis. That's a stupid assumption of course...

Back to real work : D-21.

Again dialog ... :(

Karavaev Denis9-Nov-02 6:29

Karavaev Denis

9-Nov-02 6:29

Ok, thanks everyone, but I have one more question.
To gett callback of my modal dialog I use this code:

ModalDlgClass myDlg = new ModalDlgClass();
if(myDlg.ShowDialog() == DialogResult.OK)
{
//Do smf.
}

But in the modal dialog there is a small problem ...
I need to check something before close it.

if(textBox1.Text.Length == 0)
{
//cheking and need returf focus to modal dialog
}
else
{
//do smf else, then
this.Close(); // I need 2 close it ONLY if textBox1 is not emty
}

But if my textBox1 is empty after checking modal dialog is closing ... is there any way not to close it?

thanks

=====================
http://wasp.elcat.kg

Re: Well...

Masaaki Onishi10-Nov-02 8:15

Masaaki Onishi

10-Nov-02 8:15

Hello, the codegurus around the world.;)

If you work for MFC, you will figure it out.
Maybe, you just declare MyDialog_OnClose message method, and filter
the textbox input.
And, if there is no input, just return before the base class Close is called.
Just put "return".
I believe that this works.

Please, don't send me your email about your questions directly.
Have a nice day!
Sonork - 100.10571:vcdeveloper Wink | ;)

-Masaaki Onishi-

Re: Well...

Karavaev Denis10-Nov-02 17:36

Karavaev Denis

10-Nov-02 17:36

I deed, but it, not working.
I have modal dialog. And it's closing even if i put 'return'.
Maybe it is becourse I click on button with 'OK' dialog properties?
But is it only way to get response from my Modal dialog?

=====================
http://wasp.elcat.kg

Re: Ooops.

Masaaki Onishi10-Nov-02 18:29

Masaaki Onishi

10-Nov-02 18:29

Hello, the codegurus around the world.;)

Oooops, you're right because I got the same result.
So, I asked "HELP" of VC#.

1) Use DialogResult.NONE

protected void btnOK_Click (object sender, System.EventArgs e)
{
        // OK button clicked.
	// get new message.
	strMessage = txtMessage.Text;

	if(strMessage == "") 
	{
		MessageBox.Show(this, "Error");
		DialogResult = DialogResult.None;
	}
}

2) Disable OK button if TextBox is empty

private void Msg_TextChanged(object sender, System.EventArgs e)
{
   if(txtMessage.Text == "")
	btnOK.Enabled = false;
   else
	btnOK.Enabled = true;
}

Please, don't send me your email about your questions directly.
Have a nice day!
Sonork - 100.10571:vcdeveloper Wink | ;)

-Masaaki Onishi-

Re: Ooops.

Karavaev Denis11-Nov-02 3:36

Karavaev Denis

11-Nov-02 3:36

Yah!!! thanks,

Nice idea to lock button till text is empty! Wink | ;)

=====================
http://wasp.elcat.kg

Re: Again dialog ... :(

mikasa11-Nov-02 7:52

mikasa

11-Nov-02 7:52

I had to do this in VB.NET. What I did was I didn't "HardCode" the "Dialog Result Codes" into my Command Buttons. When the User clicked the "Login" Button of my Form, I would Validate the Login info, if it was Correct, I would just Type "Return DialogResult.OK", otherwise I would not return anything.

A simple function pointer question...

Dave Kerr9-Nov-02 1:40

Dave Kerr

9-Nov-02 1:40

Hi I'm havinh real trouble using this one OpenGL function I'm trying to import into my app. The C function is declared as this:-

void gluTessCallback(GLUtesselator* obj, GLenum type, void(*fn)());

I know that GLUtesselator* is basically just an IntPtr, as I've imported other functions with it in, and they've worked fine. Similarly, GLenum is just a UInt. But what do I do with the void function pointer?
I have declared delegates for all of the possible function types it could be, (depending on the 'type' variable), but I don't know where to go from there.

MSDN only has info for function pointers that are always a set type, but with this function, the pointer can be to a number of different types of function.

Please help me out here!

Thanks in advance
Dave

Dave Kerr
focus_business@hotmail.com
www.focus.esmartweb.com

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