Re: How to Hide ScrollBar of RichtextBox - C# Discussion Boards

Re: bitmap constructor throws InvalidArgumentException

6-Jul-04 3:45

Pain,

It's the numerical values, they must be invalid for creating a 24bit bmp.
If you change them, say 1,1 then it works just fine.

Hope that helps

Kev Pearman MCP

Dave Kreskowiak6-Jul-04 5:50

Dave Kreskowiak

6-Jul-04 5:50

The problem is that your image, at 23622 pixels wide and 18897 pixels high, and 24bpp, is about 1.3GB in size. If you don't have the memory to hold such a huge image, you'll get InvalidArgumentException's.

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

How to Hide ScrollBar of RichtextBox

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.

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."

Jay Shankar5-Jul-04 23:30

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.

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#
My Articles

Jay Shankar6-Jul-04 18:04

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

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

Jay Shankar12-Jul-04 22:54

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.

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

Jay Shankar21-Jul-04 18:27

Re: C#, XML, XPath problem

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

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

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

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