Re: Owner drawn Menu Items - C# Discussion Boards

20-Feb-04 0:20

I would like to get rid of (actually move) the arrow in the menu item which is used to show the existence of menu items to the right of the menu item. The reason for this is that I need to show the menu on the right hand side of the form and when I change the RightToLeft property, the arrow appears in the center of the menu item. I've made several different attempts but to no avail. It doesn't seem to matter whether I use owner draw or not. Can somebody help?

Heath Stewart20-Feb-04 3:30

20-Feb-04 3:30

There's plenty of articles here on CodeProject about owner drawing menus. Just try a search[^].

There's also a pretty basic - but complete - example on Dr. GUI .NET some time back, Controls and Icons a la .NET[^]. The example is in VB.NET, but if you truly understand the .NET Framework, you'll have no problems translating it to C# if you need that. There's also a pretty good "Cutting Edge" article in MSDN Magazine, Owner-drawing in .NET[^], which deals completely with menus.

Microsoft MVP, Visual C#
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Katalin20-Feb-04 4:28

20-Feb-04 4:28

Thanks but I still don't see from these articles what to do in order to get rid of the arrows. They are always drawn when one or more submenus are added to a menu item (to its right). These arrows appear in black while viewing the menu item and in white when selecting (hovering over) it. This occurs regardless of which colors are set in the DrawString or FillRectangle methods (in the owner draw procedure).

I put some debugging print statements into an overridden WndProc method, but I fail to see which event (in Message) would do this drawing.

I also attempted to create a graphics object in the MenuItemPopUp method but when I attempted to create such an object from the handle I received from the sender (MenuItem) the program just crashed giving me an out of memory error msg. Seems like creating a graphics object from the window handle of the form object is allowed but doing the same from the window handle of the menu is not. (Although, even if this had succeeded I have my doubts as to whether this would solve my problem).

So, if anybody out there has succeeded in getting rid of (or moving) these arrows, I would appreciate it if you could tell me.

Heath Stewart20-Feb-04 6:14

20-Feb-04 6:14

The MenuItem.DrawItem event gives you the the Graphics object you should be using. It's possible the out-of-memory exception is because a Graphics object has already been created from the window handle, which obtained the HDC internally. There can only exist one HDC for the drawing operation, IIRC.

I threw together a quick test and see what you mean. Unfortunately, .NET probably has nothing to do with this since it merely encapsulates the Windows APIs. You could always try adjusting the SizeF in which the text is drawn so that the menu item is long enough to display some space between the arrow and the text. I have heard that there are some quirks in right-to-left reading orders, and this appears to be one. Googling for this subject pretty much comes up with that idea - offsetting your text appropriately.

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Katalin22-Feb-04 21:47

22-Feb-04 21:47

Thank you for your response and for trying this out with a test program. I increased the width of the menu item window in MeasureItem and it does look better. Unfortunately, the arrows are on the wrong side of the text and are pointing in the wrong direction. What really baffles me is that I can't find the Windows API message which probably repaints the Menu item after I paint it in DrawItem. This message ought to be one of the messages coming through the WndProc method.

By the way the out-of-memory exception I get is not in MenuItem.DrawItem but in the PopUp event method. It happens when I attempt to create a Graphics object from the window handle of the MenuItem. I wonder whether this is a bug in .NET (with C#).

Heath Stewart23-Feb-04 3:32

23-Feb-04 3:32

When displaying the underlying popup window for a menu, an HDC would also be used. From experience, creating an additional one causes similar problems.

When I threw together my simple - and very stupid! - application and set RightToLeft on the main form to RighToLeft.Yes (the child controls were left as the default RightToLeft.Inherit), the arrows were on the right (left, that is! Smile | :)

) side and pointing the right (left) direction.

Are you trying to perform right-to-left drawing yourself without regard to the RightToLeft property?

Microsoft MVP, Visual C#
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Katalin23-Feb-04 3:51

23-Feb-04 3:51

I pretty much gave up on this whole endeavor now. Instead I am now keeping the RightToLeft as Inherit (that is NO) and instead placed a huge empty MenuItem (filled with spaces and set to Enabled = False). But what I was trying to do was to keep the labels on my menu items as Left adjusted (by using tabs in my Format.SetTabStops. But for me the arrows showed up on the left and pointed to the left and since I am using English this didn't look so great (especially when the arrows came in the middle of the labels). When I attempted this, I did set the RightToLeft value to be YES.

Heath Stewart23-Feb-04 3:56

23-Feb-04 3:56

Wait, you used tab-stops? The default menuing provided by Windows uses these for arrow and shortcut key placement. Set 2 or 3 tab stops (calculating in the maximum SizeF.Width from Graphics.MeasureString) and see what you come up with.

Microsoft MVP, Visual C#
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Katalin23-Feb-04 22:07

COM Problem - StrRetToStr()

23-Feb-04 22:07

Just for the hell of it I set up some tabs (though it turns out I just needed one). This is my code:

float[] tabs = {15};
Format.SetTabStops(0, tabs);
string MenuItmStr = "\tX\t" + Item.Text;

The X now covers the arrow though the arrow is still there. Seems like it somehow gets drawn after my DrawItem gets executed.

Tristan Rhodes20-Feb-04 0:14

Tristan Rhodes

20-Feb-04 0:14

I'm trying to run the GetDisplayName method of a folder (in this case, the desktop folder). It all executes perfectly as far as I can see, until it reaches the StrRetToStr method, where it crashes with a null pointer error.

I'm slightly confused as its practicaly identical to the tutorial on this site.

The code follows:

<br />
			//Allocate Desktop pidl<br />
			desktopPIDL = new IntPtr();<br />
<br />
			//Get desktop folder<br />
			COMStuff.SHGetDesktopFolder(out desktopPIDL);<br />
<br />
			//Set Shell interface type<br />
			Type shellType = typeof(IShellFolder);<br />
<br />
			//Build COM object<br />
			IShellFolder shellFolder = (IShellFolder)<br />
				Marshal.GetTypedObjectForIUnknown(thing, shellType);<br />
<br />
<br />
			//Alcoate Interface ptr and relative PIDL ptr<br />
			IntPtr interfacePtr = new IntPtr();<br />
			IntPtr relativePIDL = new IntPtr();<br />
			<br />
			//Get GUID<br />
			Guid myGUID = Marshal.GenerateGuidForType(shellType);<br />
			<br />
			//Bind to parent<br />
			result = COMStuff.SHBindToParent(pidl,<br />
				myGUID,		//GUID!<br />
				out interfacePtr,<br />
				out relativePIDL);<br />
<br />
			//Build myShellFolder<br />
			IShellFolder myShellFolder = (IShellFolder)Marshal.GetTypedObjectForIUnknown(interfacePtr,shellType);<br />
<br />
			//NOTE: Must be tied to parent folder!<br />
			//Allocate STRRET<br />
			mySTRRET = new STRRET();<br />
			//Get relative PIDL<br />
			result = myShellFolder.GetDisplayNameOf(relativePIDL,SHGDN_Flags.SHGDN_NORMAL | SHGDN_Flags.SHGDN_FORPARSING<br />
						,ref mySTRRET);<br />
			//mySTRRET.uType = 2;<br />
<br />
<br />
			//Allocate File name string<br />
			myFileName = new string(' ',128);<br />
<br />
			//Run Conversion<br />
			result = COMStuff.StrRetToStr(ref mySTRRET, relativePIDL, out myFileName);	<br />

The calling code above gets to the last line before crashing.. STRRET has all it's values set (except type... the uint is always 0 for this struct).

The STRRET struct and the StrRetToStr method are declared as follows:

<br />
	[StructLayout(LayoutKind.Explicit, CharSet = CharSet.Auto)]<br />
	public struct STRRET <br />
	{<br />
		[FieldOffset(0)]<br />
		public uint uType;		//1 = PoleStr, 2 = int Offset, 3 = string (char[Max_Path])<br />
<br />
		[FieldOffset(4)]<br />
		public IntPtr pOleStr;	//Pointer to the OLE string	<br />
<br />
		[FieldOffset(4)]<br />
		public UInt32 uOffset;	//Offset into the IID list<br />
<br />
		[FieldOffset(4)]<br />
		public IntPtr cStr;		//String Pointer<br />
<br />
	}<br />
<br />
<br />
<br />
		[DllImport("shlwapi.dll", CharSet=CharSet.Auto)]<br />
		public static extern int StrRetToStr(<br />
			ref STRRET pstr,			<br />
			IntPtr pidl,<br />
			[MarshalAs(UnmanagedType.BStr)]<br />
			out string pbstring);<br />
<br />

If anyone could shed some light on this subject, it would be most grateful.

regards

Cata

(This is actualy an expantion on a thread I posted 2 weeks ago, but I've been supremely busy, so it's lost in the archives somewhere)

run command

Rob Tomson20-Feb-04 0:01

Rob Tomson

20-Feb-04 0:01

how would i run a command from c# like i would at the command prompt? (just an example: command="explorer /e,c:")

thanks,
Rob Tomson

--
There are 10 kinds of people. Those who understand binary and those who don't.

Re: run command

Mazdak20-Feb-04 0:54

Mazdak

20-Feb-04 0:54

Look at Process class and specifly its method Process.Start() and StartInfo property.

Mazy

You're face to face,
With the man who sold the world - David Bowie

Re: run command

Jaclyn20-Feb-04 1:00

Jaclyn

20-Feb-04 1:00

You can use the code below to run an application.
The arguments in this case is the application's exe as the first argument & the second argument is the actual file you want to open.

You can also just specify the file & it will open in the default application.
I'm sure it must be possible to just specify the application as well.

System.Diagnostics.Process.Start("WMPlayer.exe", "C:\\test.wmv");

Hope it helps Smile | :)

Jaclyn

Re: run command

Rob Tomson20-Feb-04 5:29

Rob Tomson

20-Feb-04 5:29

i was actually looking at that but since it said Diagnostics i didn't know if it was meant to be used for that or something else. what i want to do is running a third party console program silently. using the Process.Start it opens up a command prompt box for me and does exactly what i want but is there a way to not show the window?

thanks,
Rob Tomson

--
There are 10 kinds of people. Those who understand binary and those who don't.

ScrollableControl

PaulStat19-Feb-04 23:36

PaulStat

19-Feb-04 23:36

I've created a class which extends the ScrollableControl, now this class is basically a control which contains images, i.e. a viewer. Now my problem is is that according to the documentation 'AutoScroll' allows the user to scroll to any CONTROLS outside of the bounds. The images however which are being displayed are not controls and are a unique type, how can I activate the scroll bars anyway????

Re: ScrollableControl

Werdna20-Feb-04 3:33

Werdna

20-Feb-04 3:33

You have to set AutoScroll to true, and AutoScrollMinSize to total size that you want to have viewable. If you're doing drawing yourself, you have to make sure to adjust positions in your OnPaint event.
best way to do that is put:
pe.Graphics.TranslateTransform (AutoScrollPosition.X, AutoScrollPosition.Y);
at the top of onPaint

Re: ScrollableControl

Heath Stewart20-Feb-04 3:42