Re: String Width - C# Discussion Boards

4-Jan-04 18:19

The default implementation of the ListView class doesn't support virtual lists. Instead, you'll have to extend the ListView class with your own class and override WndProc to provide a lot of native concepts. Keep in mind that the ListView control is just a wrapper for the List View common control. There are ways you can do this, but you'll have to P/Invoke functions like SendMessage, create many differents structs, and define many enums or constants that reflect the values of all the Windows messages and notifications. See Windows Controls[^] in the MSDN Library for details. You should be familiar with Win32 APIs and programming.

You could also try searching CP or google the 'net for existing examples. It wouldn't surprise me if anyone has already done this.

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String Width

Luther Baker4-Jan-04 10:38

4-Jan-04 10:38

Is there a simple way to explicitly get the width of text in a control?

In general, I would like to dynamically size labels, buttons, listboxes, etc. depending on their contents.

I don't have to get the font, draw the text somewhere else and measure it do I?

Thanks,

-Luther

ne20004-Jan-04 10:43

ne2000

4-Jan-04 10:43

I think you should check out Graphics.MeasureString

Cheers,
Henrik

markdbd4-Jan-04 19:31

markdbd

4-Jan-04 19:31

Thanks I was also looking for this.

Luther Baker6-Jan-04 18:27

6-Jan-04 18:27

That looks like its worth a shot.

I guess, if text on a button spans 2 lines, I need to get the "size" of the button's print area.
That may be different than the size of the button right?

Maybe there is a "client area size" property or something ...

In any case, that call starts me off.

Thanks,

-Luther

Luther Baker7-Jan-04 11:39

7-Jan-04 11:39

Ok - I know this is a naive question, but where do I get a graphics object.

I am not in an event handler. I am in my custom control's constructor. Its not attached to anything. I just create a button and I've set the Text property, and now I want to set the Size property.

It seems that I can't create an instance of the graphics object ... and this is not a static method.

I'm not a GDI+ expert but I would guess that I can't just create a Graphics object because there is more to the drawing context that must be defined. Where am I drawing? Which window are we drawing to, etc. Maybe I can must measure the string size in the OnPaint handler (using the parameterized graphics object).

Thanks,

-Luther

ComboBox

Luther Baker4-Jan-04 9:46

4-Jan-04 9:46

Is there a switch to disallow manual text entry into a ComboBox?

Or do I need to catch the KeyPress event and impl this myself?

-Luther

Re: ComboBox

Nick Parker4-Jan-04 10:06

Nick Parker

4-Jan-04 10:06

You need to set the ComboBoxStyle to DropDownList. Check ComboBoxStyle Enumeration[^] for further details.

- Nick Parker
My Blog

Re: ComboBox

Charlie Williams4-Jan-04 10:07

Charlie Williams

4-Jan-04 10:07

Set the control's DropDownStyle to DropDownList

Charlie

if(!curlies){ return; }

Re: ComboBox

Luther Baker4-Jan-04 10:39

4-Jan-04 10:39

Thank you both.

-Luther

Custom Control

Luther Baker4-Jan-04 8:59

4-Jan-04 8:59

I would like to make the following custom control.

A button, that opens a drop down list. Essentially, a combo box, but I don't want the appearance of a combo box. I want a button.

My initial problem is this. The drop down list may appear outside of its parent's bounds. Imagine a thin panel on the top of a form (like a toolbar) with this control attached to it. The control may have to draw the drop down list ON TOP OF the other controls immediately beneath the toolbar.

I'm used to something like css (position: absoloute). I guess the MainMenu does this. Do I need to custom draw the drop down list control?

Suggestions?

-Luther

Heath Stewart4-Jan-04 18:15

4-Jan-04 18:15

Why not just use a ContextMenu, which is already supported? Just start tracking the ContextMenu in the coordinate space of the container of the Button so that it aligns properly with the Button in question. See the Control.PointToClient method to convert coordinate spaces back and forth. Because the Button.Location is already in the coordinate space of the container, you could also just add the Height and Width appropriately, saving you a lot of work. The ContextMenu control will also extend past the bounds of the container.

Otherwise, you can use a simple popup Window (with the WS_POPUP style when you consider the native implementation of most controls in the .NET BCL). This is all the ContextMenu is when you get the heart of it.

Luther Baker6-Jan-04 18:21

6-Jan-04 18:21

Thanks Heath.

Ddynamically placing the context menu might be just fine.

If I wanted more control over the look of the popup window, I may try the WS_POPUP window approach as well.

But, are you implying that I may have to use some native calls. I've written simple windows programs before - but I'm not exactly sure if thats what you mean.

Would I be on the right track to do this natively by - creating a WS_POPUP window and writing a wndproc to catch mouseover, mouse out and click events? I've seen several posts that link to native DLLs and use SendMessage, etc, so I think I could work this out.

But, I just want to be sure that I'm not missing something ... like, creating a panel in C# and somehow makeing it visible and invisible lower than the button I am using to trigger it. I've tried this - and at first attempt, the panel always shows up UNDERNEATH the controls lower in the client area.

I'm betting I can get that final idea could work if I could somehow make change the panel's z order to higher than the controls lower in the client area. The hypothetical problem I can think of is that the controls lower in the client area don't attach to the same parent, and so, maybe this is recursive so I need to trace back until the parents attach to the same form or root panel, and makes sure the popup menu parent is at a higher z index ...

If you have more time, your suggestions are greatly appreciated. For now, I'm off.

Thanks,

-Luther

Heath Stewart6-Jan-04 18:59

6-Jan-04 18:59

A Panel won't work because it's a child window and nothing more. You have to use a popup window because it must be able to extend beyond its container's bounds. You could use a Form, but there's just too much overhead, IMO.

Yes, what I was talking about was good ol' Win32 programming. Fortunately, .NET can help even there. Remember that all the controls in System.Windows.Forms are just wrappers of Common Controls. There's even classes like NativeWindow that can give you a wrapper to a native window. It wouldn't be too difficult to do. I'm sure there's examples out there, too, although good, specific keywords might be hard to determine.

Luther Baker6-Jan-04 19:26

I should use what provider?

6-Jan-04 19:26

Perfect. You just saved me a night.

Thanks for the direction.

-Luther

god4k4-Jan-04 7:23

god4k

4-Jan-04 7:23

Hi, Guru

I retrieve procedure parameter information by the code below.

OleDbConnection cnn = (OleDbConnection)idbConn;
OleDbCommand cmd = cnn.CreateCommand();
cmd.CommandText = "procedurename";//Procedure-Name
cmd.CommandType = CommandType.StoredProcedure;
OleDbCommandBuilder.DeriveParameters(cmd);
foreach(OleDbParameter par in cmd.Parameters)
{
MessageBox.Show(par.ParameterName + "\n" + par.Direction.ToString() + "\n" + par.OleDbType.ToString());
}

The problem is the provider not supported and return this error message...
"Retrieving procedure parameter information is not supported by the 'Microsoft.Jet.OLEDB.4.0' provider."

To do this, do you know what provider support.

Sorry for bad English.

Thank you.

Re: I should use what provider?

Guillermo Rivero4-Jan-04 8:11

Guillermo Rivero

4-Jan-04 8:11

What DataBase are you using ?

Free your mind...

Re: I should use what provider?

Heath Stewart4-Jan-04 8:37

Re: I should use what provider?

4-Jan-04 8:37

The Microsoft Jet provider is used to access .mdb files, which are commonly equated with Microsoft Access, though MS Access is not needed to create and use these .mdb files (it's just really handy, and I believe required for forms and reports manipulation).

Heath Stewart4-Jan-04 8:45