C# Discussion Boards - CodeProject

Jay Shankar5-Jul-04 22:30

5-Jul-04 22:30

Dear CPians,

I want to hide RichtextBox's ScrollBar or set its width = 0, since I am scrolling the RichtextBox programetically in runtime using API methods (SetScrollPos , GetScrollPos, PostMessageA).
How to achieve this?

Thanks in advance,
Regards,

Jay.

Re: How to Hide ScrollBar of RichtextBox

Stefan Troschuetz5-Jul-04 22:59

Stefan Troschuetz

5-Jul-04 22:59

What about the RichTextBox.ScrollBars property!? MSDN[^] says "You can also use this property to remove scroll bars from the control to restrict scrolling the contents of the control."

Re: How to Hide ScrollBar of RichtextBox

Jay Shankar5-Jul-04 23:30

Jay Shankar

5-Jul-04 23:30

This would not solve my purpose.
Actually I want to syncronise the scrolling of two RichTextBoxes,
say RichTextBox1 and RichTextBox2

I am overriding WndProc method of RichTextBox1 and sending System.Windows.Forms.Message m to RichTextBox2 by raising an event and passing m.WParam, m.LParam.

If I set RichTextBox2.ScrollBars = None, the above would not work.

Re: How to Hide ScrollBar of RichtextBox

Heath Stewart6-Jul-04 5:45

Heath Stewart

6-Jul-04 5:45

What does synchronization have to do with "How to Hide ScrollBar of RichtextBox", which is what your subject says? The first reply answered your subject.

You don't pass a Message to WndProc. The RichTextBox encapsulates the Rich Edit common control, which manages the scroll bars itself. You only need to P/Invoke SendMessage (or SetScrollPos, as you asked about before) and set the scroll position. This results in the scroll messages being sent and the scroll bars adjusted automatically, all something done by the Rich edit control.

The only reason to override WndProc is to handle the WM_HSCROLL (0x0114) and WM_VSCROLL (0x0115) messages. As documented in the Platform SDK, the high-order word is the actual position, where the low-order word is the scrolling request. You should read the documentation for these two messages (though they are alike) in the Platform SDK on MSDN[^].

What you then do is call the P/Invoke'd SendMessage (see pinvoke.net[^] if you need help with the signature) with the same message (WM_HSCROLL or WM_VSCROLL) and the same parameters. Do not call WndProc directly. SendMessage (or use PostMessage for asynchronous operations, which should work in most cases) does this.

Microsoft MVP, Visual C#
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Re: How to Hide ScrollBar of RichtextBox

Jay Shankar6-Jul-04 18:04

Jay Shankar

6-Jul-04 18:04

Dear Heath,
I am doing the same. Please refer to the code below:

protected override void WndProc(ref System.Windows.Forms.Message m)
{
	if(m.Msg == WM_MOUSEWHEEL) //WM_MOUSEWHEEL 0x020a
	{
		if(Control.ModifierKeys != Keys.Control)
		{
			MouseWheelRollingEventArgs e = new 
				MouseWheelRollingEventArgs(m.WParam, m.LParam);
			MouseWheelRolling(this, e);
			base.WndProc(ref m); 

		}
		else
		{
			return;
		}

	}
	else if( m.Msg == WM_VSCROLL )
	{
		//process similarly for scroll, below 
		//.....
		//.....
		base.WndProc (ref m); 
	}
	else
	{
		base.WndProc (ref m);  
	}

}

private void rtb_MouseWheelRolling(object sender, TextEditor.MouseWheelRollingEventArgs e)
{

	//note : lineSrNo is the other richTextBox I am syncronising
	const int WM_MOUSEWHELL = 0x020a;
	PostMessageA((int)lineSrNo.Handle,WM_MOUSEWHELL, (int) e.wp, (int) e.lp);
}

rtb and lineSrNo are the two richTextBoxes, I want to syncronise.
lineSrNo richTextBox contains the lineNumbers of rtb richTextBox.
When ever user scrolls the rtb richTextBox(using MouseWheel rolling or ScrollBar) correspondingly lineSrNo richTextBox should also get scrolled.
Line numbers are added in the lineSrNo richTextBox when ever user enters any line in rtb richTextBox.

lineSrNo richTextBox Locked property is set to True and I am scrolling it programetically.

I am able to acheive the target, but I do not want scrollBar in lineSrNo richTextBox

That is the reason, I am asking the way out to hide the scrollBar of the richTextBox or set its width to 0.

Regards,

Jay

Re: How to Hide ScrollBar of RichtextBox

Heath Stewart7-Jul-04 3:29

Heath Stewart

7-Jul-04 3:29

Have you tried getting the handle to the scroll bars (use FindWindowEx, or some controls actually define a message to return the scrollbar handle) and simply P/Invoking SetWindowsLongPtr passing ~WS_VISIBLE OR'ed with the previous style? That would literally hide the scrollbars but should still respond to scroll messages.

Microsoft MVP, Visual C#
My Articles

Re: How to Hide ScrollBar of RichtextBox

Jay Shankar12-Jul-04 22:54

Jay Shankar

12-Jul-04 22:54

I tried getting the Handle of richTextBox's scrollBar using the following code, but could not succeed. Can you please point out where am I going wrong?

public class ScrollBarHiddenRTB : System.Windows.Forms.RichTextBox
{

	[System.Runtime.InteropServices.DllImport("user32.dll")]
	public static extern IntPtr FindWindowEx(IntPtr parent, IntPtr next, string sClassName, IntPtr sWindowTitle);

	[System.Runtime.InteropServices.DllImport("user32.dll")]
	public static extern int SetWindowLongPtr( IntPtr hWnd, int nIndex, int dwNewLong);

	private  const int WS_VISIBLE = 0x10000000;

	public ScrollBarHiddenRTB() : base()
	{
		this.HandleCreated += new EventHandler(CreateRTBHandle);

	}


	private void CreateRTBHandle(object sender, EventArgs e) 
	{
		ScrollBarHiddenRTB self = sender as ScrollBarHiddenRTB;
		System.Diagnostics.Debug.Assert(self != null);
		IntPtr scrollHandle = FindWindowEx(self.Handle, IntPtr.Zero, "ScrollBar", IntPtr.Zero);
		if(scrollHandle != IntPtr.Zero)
		{
			MessageBox.Show(scrollHandle.ToString());
		}

	}

}

Regards,

Jay.

Re: How to Hide ScrollBar of RichtextBox

Heath Stewart13-Jul-04 3:26

Heath Stewart

13-Jul-04 3:26

A few tips, first: don't use <code> within a <pre> tag. The former is for in-line code, and the latter is for block code.

Also, don't handle events for the control class you're extending. It is much faster and you have more control by overriding OnHandleCreated, or any of the OnEventName handlers defined by the base class. This lets you call base.OnHandleCreated if you want (in this case you should, but there are times you might not want to when overriding WndProc, for example). It's also much faster code. To invoke a delegate, many, many IL instructions are required. To call a virtual function it's one: callvirt.

The Rich Edit control doesn't expose its scroll bars in the same way as other controls. If you look at the message documentation for the Rich Edit control like I mentioned before you might notice an EM_SHOWSCROLLBAR message you can send by P/Invoking SendMessage like so:

[DllImport("user32.dll")]
private static extern int SendMessage(IntPtr hWnd, int msg, ScrollBar sb, bool show);
private enum ScrollBar
{
  Horizontal,
  Vertical
}

Please note that this signature is not 64-bit compatible, however. In such a case, both return value and the last two params should be IntPtrs, which is a system-dependent bit width.

Then, just send EM_SHOWSCROLLBAR (0x0460) with the params you require.

Microsoft MVP, Visual C#
My Articles

Re: How to Hide ScrollBar of RichtextBox

Jay Shankar21-Jul-04 18:27

Jay Shankar

21-Jul-04 18:27

Dear Heath,
Thanks for the tips. I will keep in mind for future postings.

I tried sending EM_SHOWSCROLLBAR message by P/Invoking SendMessage, But It did not work in my case.

However, I could solve the problem by P/Invoking GetSystemMetrics, CreateRectRgn, SetWindowRgn.

I am pasting the code for future reference.

private const int SM_CXVSCROLL = 2;

//
[System.Runtime.InteropServices.DllImport("user32")] 
public static extern int GetSystemMetrics(int nIndex);
//

[System.Runtime.InteropServices.DllImport("gdi32")] 
public static extern int CreateRectRgn(int X1, int Y1, int X2, int Y2) ;
//

[System.Runtime.InteropServices.DllImport("user32")] 
public static extern int SetWindowRgn(int hwnd, int hRgn, bool bRedraw);

		
public void HideVerticalScrollBar(RichTextBox rtb)
{	
        //get scroll bar width 
	int scrollbarWidth = WinApi.GetSystemMetrics(SM_CXVSCROLL);
	// handle of the region
        int handleRgn = WinApi.CreateRectRgn(0, 0, rtb.Width , rtb.Height);
	//change the width of the rtb
	rtb.Width += scrollbarWidth; 
        //set window region
	WinApi.SetWindowRgn(rtb.Handle.ToInt32(), handleRgn, true);
}

Regards,

Jay.

C#, XML, XPath problem

velincho5-Jul-04 22:23

velincho

5-Jul-04 22:23

Hi,
I'm writing a program which manages a XML file. Here is the problem:

1)this code works ->
<?xml version="1.0"?>
<manifest identifier="manifest-5972687/packet0">
<metadata />

doc.SelectSingleNode("/manifest"); - where doc is a XmlDocument.

2)but this code doesn't ->
<?xml version="1.0"?>
<manifest xmlns="http://www.imsglobal.org/xsd/imscp_v1p1" xmlns:imsmd="http://www.imsglobal.org/xsd/imsmd_v1p2" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" identifier="MANIFEST-3F664D24-D315-486E-61AE-97BCA62EF017" xsi:schemaLocation="http://www.imsglobal.org/xsd/imscp_v1p1 imscp_v1p1.xsd http://www.imsglobal.org/xsd/imsmd_v1p2 imsmd_v1p2p2.xsd">

doc.SelectSingleNode("/manifest");

so when I try to apply the above attributes to the "manifest", I get exceptions everywhere I use the SelectSingleNode function in my code(also all XPath expressions fail to work!!).It's possible to use doc.DocumentElement; property but in this case I have to change a lot of code and this doesn't seem to me logical Smile | :)

. Can you help me? Thanks in advance.

Best Regards
Velin

Re: C#, XML, XPath problem

leppie6-Jul-04 7:26

leppie

6-Jul-04 7:26

Create an instance of a XmlNamespaceManager , and apply those extra namespaces, then pass the instance to SelectSingleNode()

^{top secret xacc-ide 0.0.1}

Re: C#, XML, XPath problem

velincho6-Jul-04 22:23

velincho

6-Jul-04 22:23

Thanks Leppie. I'll try it!

HOW TO CREATE IMAGE FRAMES FROM METAFILES

gayathri_gopi5-Jul-04 22:22

gayathri_gopi

5-Jul-04 22:22

Can i create image frames from metafiles.

My program works for creating image frames from any types of images, but not from metafiles.

Can i know how to create image frames from metafile images and also for a combination of metafile images and others like gif,jpeg..?

DllImport

Anonymous5-Jul-04 22:12

Anonymous

5-Jul-04 22:12

I am having 2 unrelated problems and was hoping one of you would be able to help me.
Firstly i have just downloaded the directX SDK, I know how to include the libraries in VS6 but i'm now using 2003 and i don't know what to do to get the IDE to recognise
using System.Microsoft.DirectX;

Secondly, i am trying to use the DllImport attribute but am getting a message saying the type or namespace "DllImport" could not be found. The line of code is
[DllImport("user32.dll")]
Followed by a function definition

Any help that you guys can give me to solve these problems would be greatly appreciated.

Re: DllImport

Anonymous5-Jul-04 22:26

Anonymous

5-Jul-04 22:26

I have figured out the DllImport problem, i wasn't including the
System.Runtime.InteropServices;

Still having the directX problem though.

Re: DllImport

Stefan Troschuetz5-Jul-04 22:43

Stefan Troschuetz

5-Jul-04 22:43

1. It sounds like you missed to add a reference for the library. The using directive only permits the use of types in a namespace, such that, you do not have to qualify the use of a type in that namespace.
To reference the library, go to the solution explorer, right-click on References and select "Add reference".

2.
You'll have to import the types of System.Runtime.InteropServices namespace to use the DllImportAttribute Class the way your doing.

using System.Runtime.InteropServices;
[DllImport("user32.dll")]
Followed by a function definition

DirectX

Anonymous6-Jul-04 3:16

Anonymous

6-Jul-04 3:16

OK, sorted the DllImport problem, thanks.

Back to directX. What you are saying is true, i am missing the reference to the assembly but, DirectX is huge, you wouldn't add a reference to each DLL manually.

In Visual Studio 6, you added a reference to the relevant library folder and include folder, then you could just use the functions as though they were system functions. In 2003, if you include the relevant libraries then you can either use the fully qualified namesapce
Microsoft.DirectX.DirectDraw etc
or have a using statement as you would with any other system library.

Anyone that knows what i am doing wrong, i have installed directX SDK 9, or knows of a good tutorial for getting up and running with managed DirectX, your help would be appreciated.

Re: DirectX

Stefan Troschuetz6-Jul-04 3:48

Stefan Troschuetz

6-Jul-04 3:48

There are some articles[^] available here on CodeProject.
Also there is a preliminary documentation on MSDN[^]

Is it possible to edit a bitmap programmatically?

Pain_Elemental5-Jul-04 21:14

Pain_Elemental

5-Jul-04 21:14

Hi all,
has anybody ever tried to edit a bitmap programatically?
I have a bitmap of a printed circuit board, but around the board are white margins.
I would like to remove the white margins in my program.

Is this possible?

Best Regards
Bernd

-------------------------------------------
The light at the end of the tunnel has been switched off temporarily due to budget problems...

Re: Is it possible to edit a bitmap programmatically?

Dave Kreskowiak6-Jul-04 5:17

Dave Kreskowiak

6-Jul-04 5:17

Of course it is. Programs like Photoshop do this all the time. The real question is how your going to detect the edge between the image and the white space you want to get rid of and what you want to do about it. DO you replace it with the green PCB or do you crop the image. There are all kinds of algorithms around for edge detection, but what will work for you is up t your own testing and research.

Edge Detection Algorithm[^] searh results on Yahoo.

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

Re: Is it possible to edit a bitmap programmatically?

Pain_Elemental6-Jul-04 19:50

Pain_Elemental

6-Jul-04 19:50

Thanks!
I'll have a look at this.

-------------------------------------------
The light at the end of the tunnel has been switched off temporarily due to budget problems...

Wanna Disscussion Forum

RadhaKrishan5-Jul-04 21:14

RadhaKrishan

5-Jul-04 21:14

I am not familiar with Discussion Forum.

Re: Wanna Disscussion Forum

Dave Kreskowiak6-Jul-04 4:57

Dave Kreskowiak

6-Jul-04 4:57

What's not to understand? You go there, you post questions, you read responses and replies... You obviously got part of it right, you posted something here.

I take it you had a more specific question about some discussion forum software?

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

List of installed fonts ?

sachinkalse5-Jul-04 20:34

sachinkalse

5-Jul-04 20:34

How to get the list of installed fonts corresponding to any perticular charactor set? eg. if I want to get Japanese supporting font list (corresponding to char set Shift_JIS), how to do it?
please guide

Re: List of installed fonts ?

Heath Stewart6-Jul-04 6:03

Heath Stewart

6-Jul-04 6:03

You can get a list of the installed fonts by instantiating System.Drawing.Text.InstalledFontCollection. Enumerate through the FontFamilies array property. This information won't tell you about which character set the font supports, however. Character sets and fonts are two separate things. Perhaps there's a few bits in a font file that determine which charset a font supports, but I'm not aware of any.

The only way to tell is to either try drawing a character from that charset using that font and see if it works, or create some sort of font driver that lets you dig into the actual font data, which would be quite a feat since you need to somehow use the font handle to get the actual font file and examine the structure. Also keep in mind that there's many different types of font files, so this would be a very difficult task.

Microsoft MVP, Visual C#
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