how to wrap some dll functions from VC6 - C# Discussion Boards

Re: Transparent Label on a Progressbar?

24-Mar-04 9:54

If your goal is display a message while the progress bar increments (like the percentage, which was common with older controls), you might be better off just extending the existing ProgressBar and provide your own painting by overridding OnPaint (do your drawing after calling base.OnPaint to make sure that the progress bar itself is draw first and your code gets drawn on top of it).

Getting the label to be transparent actually has to do with the parent forum in which it's contained. This only works in Win2K and newer (i.e., XP, 2003) since it uses layered Windows, "Windows" (or forms, dialogs) being the optimal word. A transparent color or alpha value is specified for the form an any control that uses the same color (ambience) down the chain of child controls is transparent/translucent as well. Since the ProgressBar is not a form and would paint in different colors anyway, that's one problem (the reasons go deeper, but I won't get into that).

Your painting method could be as simple as:

protected override void OnPaint(PaintEventArgs e)
{
  base.OnPaint(e);
 
  int value = (int)(Value / Maximum);
  string s = value + "%";
 
  StringFormat format = StringFormat.GenericTypographic;
  format.Alignment = StringAlignment.Center;
 
  e.Graphics.DrawString(value + "%", Font, SystemBrushes.ControlText,
    (RectangleF)Bounds, format);
}

This is untested, but should work and at least give you some ideas.

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DennisMetz24-Mar-04 11:40

DennisMetz

24-Mar-04 11:40

Thank you.

I already considered this solution, but still hoped for a Label-based solution.

Again, thanks for your help.

Regards,
Dennis

Apps without Mice

Andrew Torrance24-Mar-04 5:43

Andrew Torrance

24-Mar-04 5:43

I have just joined a company that develops its own in house apps for call centre use but does not like using mice on the call centre floor. Has anyone got experience of developing .NET apps that do not use a mouse , but still use a winform based environment . If so , are there any big pitfalls to look out for ?

Re: Apps without Mice

surgeproof24-Mar-04 6:15

surgeproof

24-Mar-04 6:15

can't think of any pitfalls.

use tab orders, key press events and suchlike. it isn't too hard to do.

surgeproof

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Re: Apps without Mice

Colin Angus Mackay24-Mar-04 6:25

Colin Angus Mackay

24-Mar-04 6:25

Make sure that the tab order of the controls is logical. i.e. the tabs move through the controls in one logical group before jumping to the next.

.
.  +--------+  +--------+     +--------+ +--------+
.  | Ctrl1A |  | Ctrl1B |     | Ctrl2A | | Ctrl2B |
.  +--------+  +--------+     +--------+ +--------+
.
.  +--------+  +--------+     +--------+ +--------+
.  | Ctrl1C |  | Ctrl1D |     | Ctrl2C | | Ctrl2D |
.  +--------+  +--------+     +--------+ +--------+

So, in this example, you'd tab from 1A to 1B to 1C to 1D rather than go for a Left-To-Right-Top-To-Bottom reading order approach.

This is just the first thought that popped in my head. There was a thread in the lounge today on bad-design (Some of it was quite funny) so the second thought is: As you test the system with your nice handy mouse beside you - resist the temptation to use it! Smile | :)

"You can have everything in life you want if you will just help enough other people get what they want." --Zig Ziglar

"On two occasions, I have been asked [by members of Parliament], 'Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?' I am not able to rightly apprehend the kind of confusion of ideas that could provoke such a question."
--Charles Babbage (1791-1871)

Re: Apps without Mice

Heath Stewart24-Mar-04 9:12

how to wrap some dll functions from VC6

24-Mar-04 9:12

Also, assigning shortcut keys to menu items is easy enough. To handle function keys or even simple key strokes you can handle the various Mouse* events (or override the various OnMouse* handlers in derived classes for more efficient and controllable code). If you need to respond to keys pressed at any time while any window is open, see the Application.AddMessageFilter method and the corresponding IMessageFilter interface which you'd implement and handle the keys trokes you want (in which case the values match up with the Keys enumeration to make things easier) by handling the various keyboard notification messages (see the Platform SDK for values).

Finally, to have a form handle key strokes while any control has the focus, see the Form.KeyPreview property documentation.

Using all that, who needs a mouse? Smile | :)

Microsoft MVP, Visual C#
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yyf24-Mar-04 5:37

yyf

24-Mar-04 5:37

Hi, everyone

I am using a dll developped in VC6. There are some functions I don't know how to wrap it in C#.

1. one function's parameter use self defined type, type definition is like this:

#ifndef LPLONG
typedef long far *LPLONG; /* 32 bit */
#endif

2. one function's parameter use 'BOOL *'

3. one function's parameter use 'char *'

4. one function's return value use 'char *'

5. one function's parameter use a structure

6. one function's parameter use a structure *

How shall I deal with these?

Thanks in advance.

Re: how to wrap some dll functions from VC6

Heath Stewart24-Mar-04 9:08

Re: how to wrap some dll functions from VC6

24-Mar-04 9:08

1. ref int
2. ref bool
3. [MarshalAs(UnmanagedType.LPStr)]string
4. [return: MarshalAs(UnmanagedType.LPStr)]string
5. Just pass the struct, but see the docs for the StructLayoutAttribute
6. ref YourStruct

All these - escept for 3 and 4 - are value types so you use ref or out (the latter if you don't need to pass any initial value to your functions). Don't use ref or out with a string because it is already a reference type. Both char* and char[] are strings since a string is only an array of characters. Since you're using char and not wchar_t (or TCHAR), you must marshal them as ANSI strings.

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yyf24-Mar-04 10:23

yyf

24-Mar-04 10:23

How about void *? Thanks.

Re: how to wrap some dll functions from VC6

Heath Stewart24-Mar-04 11:19

24-Mar-04 11:19

IntPtr

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Property Sheet

DrGreen24-Mar-04 4:41

DrGreen

24-Mar-04 4:41

Hello,

I'm trying to create a property sheet in C#. My idea is:

Create several user controls (derived from UserControl class) that represents my property pages.

Create a windows form that contains one Panel object to use like a placeholder for the pages created above.

The problem is that I don't know how to add a UserControl to a Panel object. (perhaps it's not possible...)

If someone has any idea on how to do this please reply Smile | :)

Thanks in advance

Pedro

Heath Stewart24-Mar-04 4:50

24-Mar-04 4:50

Add a TabControl to a form with a few Buttons under it. Add your UserControls to each tab. After compiling your project, the UserControls should be available in the Toolbox. If not, add them manually by adding a private field for each Type and instantiate them and initialize them in the InitializeComponent method that the Windows Forms designers use. It's not difficult and the designers aren't magic. Knowing how to add this stuff without a designer is essential in good development skills.

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DrGreen24-Mar-04 5:08

DrGreen

24-Mar-04 5:08

Hi,

Thanks for your post!

The solution you gave works well, but I was looking for something like CPropertySheet and CProperyPage in MFC.

Is there any control that we can use as placeholder for other controls?

Thanks again.

By the way, I like programming with the keyboard, not with the mouse Big Grin | :-D

Heath Stewart24-Mar-04 5:13

24-Mar-04 5:13

That's not really what you asked for, though.

If you want a good implementation, see the IPropertySheet documentation in the Platform SDK on http://msdn.microsoft.com[^]. For example, I use a implementation similar to the following in our application:

public interface IPropertyPage
{
  string Title { get; }
  void Save();
  void Cancel();
  event PropertyChangedEventHandler PropertyChanged;
}

Implement this type of interface on your control. Then create a PropertySheet class that allows you to add IPropertyPage implementations to it. When you call ShowDialog on your PropertySheet (should derive from Form) it has all the pages in a TabControl. When the event is fired, enable the Apply button. When Apply or Save is clicked, call Save on each IPropertyPage in your collection and close the dialog if Save was clicked (it annoys me to no end when people click Apply then OK since OK is supposed to apply changes and close and - with all Microsoft implementations - does).

This is very similar to how MFC and the Windows Shell interfaces do it.

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Treeview context menu remains visible

DrGreen24-Mar-04 5:27

DrGreen

24-Mar-04 5:27

Hello again!

That's exactly what I was looking for!

Thanks for your time

Pedro

CStiefeling24-Mar-04 4:26

CStiefeling

24-Mar-04 4:26

Hi All,

I have a Windows Forms app with a treeview control. I'm trying to add a 'Rename' command to the context menu. The event handler for the context menu looks like the following:

private void cmMTRename_Click(object sender, System.EventArgs e)
{
if (tvModelTree.SelectedNode != null)
tvModelTree.SelectedNode.BeginEdit();
}

The node goes into edit mode but the context menu stays visible. Is there a way to hide the context menu prior to putting the node into edit mode?

Thanks,
Chris

Re: Treeview context menu remains visible

CStiefeling24-Mar-04 4:35

CStiefeling

24-Mar-04 4:35

I was outsmarted by the tree control.

I was handling the MouseUp event to display the context menu. It seems the treeview already does this for me so I was displaying it a second time.

Thanks.
Chris

Registry Entry

Guinness4Strength24-Mar-04 3:12

Guinness4Strength

24-Mar-04 3:12

I've created an MSI installer with VS.NET 2003 which runs great. I've created two file type associations. The association is made, but when I right click on the associated file and view the proerites I notice something strange. The "File Type" information is correct = "My Prog File"
but the "Opens with:" data is not correct, it just shows the program icon and not the name. I've tracked it down to a registry entry:
[HKEY_CURRENT_USER\Software\Microsoft\Windows\ShellNoRoam\MUICache]
There is a registry string in there called:
"C:\Program Files\MyCompany\MyProgram Folder\MyProgram.exe"
the value for this string is blank. When I assign the value of "MyProgram.exe" to the entry, the associated file property page now reflect both the program icon and name in the "Opens with:" area.

Does anyone how this getts filled in ? Am I missing some kind of description property in my assemby ?

Any thoughts on how to fix this would be very much appreciated.

Guinness4Strength24-Mar-04 3:28

Guinness4Strength

24-Mar-04 3:28

I figured it out...I was filling inthe AssembyInfo.cs attribute sections.

surgeproof24-Mar-04 6:17

surgeproof

24-Mar-04 6:17

glad you sorted it! :p

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Jeremy Kimball24-Mar-04 9:30

Jeremy Kimball

24-Mar-04 9:30

Absolutely *love* the name Smile | :)

You should see my office at home...I've got damn near the whole collection of the old-style Guinness posters up.

Guinness4Strength24-Mar-04 9:32

Guinness4Strength

24-Mar-04 9:32

Everyone loves a Guinness, or should.

image on scroll bar

flmosh24-Mar-04 1:07

flmosh

24-Mar-04 1:07

Hi'
i'm using a graphical list view name 'GlacialList' and its realy very good.
i need to put an image on my scroll bar, does anyone know how can i do it?
did someone take care the scroll bar events by itself?

Re: image on scroll bar

Heath Stewart24-Mar-04 3:01