Double buffering - C# Discussion Boards

Dave Kreskowiak9-Jul-04 6:07

9-Jul-04 6:07

The .NET Framework languages we're not designed for such low level work. You would have to P/Invoke many API's and declare bunches of constants and structs to do it. There is no support in the .NET Framework for doing what your talking about. Everything about this project would be unsafe code...

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

Re: Limiting the bandwidth

pi_trek10-Jul-04 3:54

pi_trek

10-Jul-04 3:54

Thanks

Is it possible to limit (control) bandwidth in this way:

1. set socket buffer through the SetSocketOption and SocketOptionName.ReceiveBuffer to small value
2. do not take data from function call by the BeginReceive and/or do not call BegineReceive again

This should (I think) make full all buffers and the system should send same delaing packets waiting for me to make empty the buffers.

If it isnt possible could You point out some articles/codes about bandwidth limiting, please?

Thanks in advance
Piotrek

Re: Limiting the bandwidth

Dave Kreskowiak10-Jul-04 5:39

Dave Kreskowiak

10-Jul-04 5:39

Those articles are few and far between. I actually haven't been able to find any that deal with an entire NIC, just a single application.

You idea works, if your application is the one you want to limit the bandwidth on, but it will NOT work for just the Internet and will NOT work for all bandwidth on a NIC. You can't modify the buffer sizes of the TCP/IP stack globally using your method, not can you modify the buffer sizes of other applications.

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

Re: Limiting the bandwidth

pi_trek10-Jul-04 8:04

pi_trek

10-Jul-04 8:04

I'm sorry that I didn't mention it before, but I want to limit only my application.

Thanks for help.

I would like to add programmatically a new element(c# or VB.NET) in the header of my aspx page.

zoltix9-Jul-04 0:25

zoltix

9-Jul-04 0:25

In, Aspx page, I would like to add programmatically a new element(c# or VB.NET) in the header of my aspx page.

Add element=toto,atribut=coucou value =”Y”

Example

<title>Default

<toto coucou="”Y”">

Thank you a lot
bye

-=zoltx=-

Re: I would like to add programmatically a new element(c# or VB.NET) in the header of my aspx page.

Colin Angus Mackay9-Jul-04 2:14

Colin Angus Mackay

9-Jul-04 2:14

That makes no sense. Can you try explaining again what you want to do.

Also, this should really go in the ASP.NET[^] forum

"If a man empties his purse into his head, no man can take it away from him, for an investment in knowledge pays the best interest." -- Joseph E. O'Donnell

The Second EuroCPian Event will be in Brussels on the 4th of September

Can't manage to P/Invoke that Win32 API in .NET? Why not do interop the wiki way!

Re: I would like to add programmatically a new element(c# or VB.NET) in the header of my aspx page.

zoltix9-Jul-04 2:31

zoltix

9-Jul-04 2:31

I would like to add a tag in the header in my aspx page
as <base href="http/....." />

for example

.....generate by VS
<base href="http://localhost/test1" />
......

Thank you

-=zoltx=-

Double buffering

Atlemann8-Jul-04 23:59

Atlemann

8-Jul-04 23:59

I have an app that draws graphs. I want a tooltip that says the x and y value for the axis the mousepointer is over. That is not the main problem. The real problem is that the panel redpaints itself when the tooltip moves. (It now just shows the X and Y coordinate of the pointer) The tooltip moves on panel_Navigate which makes it repaint at every little mouse movement. I have read a little about Double buffering. Is there an easy way of implementing this? This did not work:

this.SetStyle(ControlStyles.UserPaint, true);
this.SetStyle(ControlStyles.AllPaintingInWmPaint, true);
this.SetStyle(ControlStyles.DoubleBuffer, true);

I have a form with a usercontrol with the panel to draw graphs inside it. I tried to make my own little derived panelclass which overrides the OnPaint method, but I just could not make it work properly because I have to draw the graphics inside the override method. That makes things a little tricky.

Any suggestions? Maybe I'm doing something wrong with the code above? I tried putting it inside all of the constructors, but nothing happend.

- Atle

Re: Double buffering

Heath Stewart9-Jul-04 4:18

Heath Stewart

9-Jul-04 4:18

First of all, the ControlStyles enumeration is flagged (attributed with the FlagsAttribute), meaning that you can use bitwise operators on it. In the Microsoft .NET BCL assemblies (base class library), any enumeration with a plural ending does (the power of naming conventions and consistency).

You can save many instructions by changing the three lines to the following:

SetStyle(ControlStyles.UserPaint | ControlStyles.DoubleBuffer
  | ControlStyles.AllPaintingInWmPaint, true);

This has to be called before the handle is created, so it's best you do this in the constructor.

Second, double-buffering isn't a blanket fix for any drawing problems. More than likely, the entire graph area is being invalidated or your redrawing the entire graph every time OnPaint is called (or your Paint event handler, which ever way you're doing it - although overriding OnPaint is faster and gives you greater control).

Instead of drawing the entire region, use the PaintEventArgs.ClipRectangle passed to the OnPaint method to determine which area needs repainting. If you repaint the entire area for a complex drawing (like a graph), double-buffering will not help much (a little, but not much).

Microsoft MVP, Visual C#
My Articles

2D Array modification

saud_a_k8-Jul-04 23:59

saud_a_k

8-Jul-04 23:59

I have a TreeView tv1, I am adding nodes and their child nodes. I am storin the values (no. of nodes) in a 2D array. like.. I have a 2D array called
int nodes[][], and a var called int parents, (both global & static),am storing the no of the parent in nodes[0][0], and the number of children that parent has in nodes[0][1].
Ex.

Say I add two parents
then:
nodes[0][0] = 1; //first parent
nodes[0][1] = 0; //no children added 
nodes[1][0] = 2; //second parent
nodes[1][1] = 0; //no children added 

then say I add two children to the first node-
then:
nodes
nodes[0][0] = 1; //first parent
nodes[0][1] = 2; //2 children added //changed 
nodes[1][0] = 2; //second parent
nodes[1][1] = 0; //no children added

This works fine but removal of nodes is the problem. I can remove a child and say
nodes[tv.SelectedNode][1]--;
I can remove a parent without children by:

nodes[tv.SelectedNode][1] = 0;<br />
  parents--;

The problem is in removing the parents with children: Mad | :mad:

I tried to make another function called CopyNodes(int [][],int selectednode)
where I make a temmp 2D array and when I encountered the var selectednode I skipped that part to copy array elements through 2 for loops (like you copy 2D arrays) But somithing is wrong & the array cannot remove the parent with children, & decrement the no. of elements of the array.
I did my best..
Please HELP ME!! Eek! | :eek:

PLEASE!!

_____________________________________________________
Yea! I could be wrong...

Re: 2D Array modification

Heath Stewart9-Jul-04 3:57

Heath Stewart

9-Jul-04 3:57

Why are you even bothering? The TreeView already stores the hierarchy of TreeNodes and you can easily get the count at any level using TreeView.Nodes.Count or TreeNode.Nodes.Count. This can even be done recursively very quickly.

What you're doing is not only unnecessary but very error prone as you've already experienced. Don't bother; the TreeView already maintains the node count so use it.

Microsoft MVP, Visual C#
My Articles

Re: 2D Array modification

saud_a_k12-Jul-04 18:21

saud_a_k

12-Jul-04 18:21

Ok thanx but how do I get the modified TreeView (ie. after deletion of the new nodes..) into a 2D array like I want ?

_____________________________________________________
Yea! I could be wrong...

Re: 2D Array modification

saud_a_k12-Jul-04 21:32

saud_a_k

12-Jul-04 21:32

I have written as function to copy the node values (count) depending on the values the tree gives :

private void CopyArr2()
		{
			p = ruletree.Nodes.Count;
			p--;
			for(int i=1; i<=p;i++)
			{
				TreeNode currnode = ruletree.Nodes[i];
				if(currnode != null)  //stupid check!
				{
					if(currnode.Nodes.Count > 1)
					{
						child[i,0] = i;
						child[i,1] = currnode.Nodes.Count;
					}
					else
					{
						child[i,0] = i;
					}

				}
			}
		}

But The resulting array has no modifications even ater I delete a node!!
why?

_____________________________________________________
Yea! I could be wrong...

How to add a button in the caption bar of a window

bouli8-Jul-04 22:11

bouli

8-Jul-04 22:11

Hi C# gurus,

I would like to know where I can get some sample code that shows how to add an additional button in the caption bar of a window? I would like to add a button on the left of the "minimize" button of the caption.

I could do this in MFC, but Windows.Forms is so different Poke tongue | ;-P

Thanks for the help.

There is no spoon.

Re: How to add a button in the caption bar of a window

Anonymous9-Jul-04 1:37

Anonymous

9-Jul-04 1:37

you can drag a button control to the form and then click on the code behind file to see the BtnClick Event handler. Under properties, you can name the button, the text on the button, etc.

However, do you mean adding a button like a COM AddIn, creating a button that way?

Re: How to add a button in the caption bar of a window

saud_a_k9-Jul-04 2:02

saud_a_k

9-Jul-04 2:02

ok I think that he wnts to put a small button beside the _ (minimize) button on top of any window caption bar= ( (new botton) _ (maximise) X)
right?

_____________________________________________________
Yea! I could be wrong...

Re: How to add a button in the caption bar of a window

Heath Stewart9-Jul-04 3:52

Heath Stewart

9-Jul-04 3:52

bouli wrote:
I could do this in MFC, but Windows.Forms is so different

Actually, it's not. Underneath it all, Windows Forms makes native API calls and sends or posts, and handles window messages.

The only difference is that not all the APIs, structs, and defs are defined in headers (you can't use headers), so you must P/Invoke the native APIs and define the structs and constants you need.

For example, in your form you want to add a caption for, extend the Form class, override WndProc, and handle the WM_NCPAINT (0x0085) message in a similar fashion as you would with MFC. There's your starting point.

Microsoft MVP, Visual C#
My Articles

Re: How to add a button in the caption bar of a window

bouli9-Jul-04 3:56

bouli

9-Jul-04 3:56

ok, I should do the same as in MFC, create dynamically a button, paint it in the Non Client area and handle the clicks by trapping the events in the WM_SYSCOMMAND; like for MFC?

There is no spoon.

Re: How to add a button in the caption bar of a window

Heath Stewart9-Jul-04 4:38

Heath Stewart

9-Jul-04 4:38

Yes; and as I said in my first reply, you need to P/Invoke the necessary APIs and define the necessary structs and constants. Don't forget to actually determine where the minimize button is. Don't always assume you know where it is. Depending on property values, the minimize button may be in a different location. Display settings (size of the caption buttons) may also be different.

There's quite a bit of code in C/C++/MFC available on the 'net that shows you how to do this correctly. Just try googling for it.

Microsoft MVP, Visual C#
My Articles

Re: How to add a button in the caption bar of a window

bouli9-Jul-04 4:45

bouli

9-Jul-04 4:45

there is an excellent implementation in emule of such a button and this implementation also take care if xp styles are enabled or not. I am looking how it is done in emule to do something similar in C#.

thanks for the help Smile | :)

There is no spoon.

Sending multiple values(Array) from one page to other

Member 11955128-Jul-04 21:14

Member 1195512

8-Jul-04 21:14

Hello Everybody,
I want to send muliple values(Array values) from one page to other.
I thing query string is not a solution. Session can be helpfull.
But some of my seniors said do not use large number of Session.
Is there any alternating way to avoid both session & query string to send array values.
Please tell me the performance effectt of Query string, Session & alternate one

Thanking You
TusharP

Re: Sending multiple values(Array) from one page to other

Heath Stewart9-Jul-04 3:29

Heath Stewart

9-Jul-04 3:29

This question should be posted in the ASP.NET forum.

Microsoft MVP, Visual C#
My Articles

Dynamiclly naming variables

saud_a_k8-Jul-04 20:45

saud_a_k

8-Jul-04 20:45

I have to name varibles depending on a count variable. I want to append it to the variable like int "newno" + count = new int();
This gives a syntax error I also tried takin the new value in a string, but that didn't work as well .. It said : A local variable named 'var' is already defined in this scope WTF | :WTF:

when I tried string var = "newno" + count;
and
int var = new int();
HelP!!

_____________________________________________________
Yea! I could be wrong...

Re: Dynamiclly naming variables

etfintnick8-Jul-04 23:04

etfintnick

8-Jul-04 23:04

Hi!

What exactly are you trying to do? Are you sure you shouldn't be
using arrays of some sort instead?

An example:

string[] varArray = new string[ sizeGoesHere ];<br />
<br />
for( int i=0; i<varArray.Length; i++ )<br />
{<br />
     varArray[i] = "Some Text and counter: "+i;<br />
}

Zerxes

Re: Dynamiclly naming variables

etfintnick8-Jul-04 23:06

etfintnick

8-Jul-04 23:06

A little error snuck in..

for( int i=0; i<<varArray.Length; i++ )

Zerxes

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