C / C++ / MFC

Changing the color of a pen or brush on the fly?

8-Jan-07 19:32

You are welcome Mr Bond Wink | ;)

Code-Frog:So if this is Pumpkinhead. Time for him to run and hide. It's an interesting thought really.

CoffeeAddict195-Jan-07 10:20

CoffeeAddict19

5-Jan-07 10:20

I know how to initialize a brush or pen to a specific color, but I couldn't find any methods for changing the contents of a brush or pen once it has been initialized. In my application the user has to be able to change it, so simply creating a new variable isn't practical. I've been deleting the brush and then re-initializing it with the new color as you can see:

void CGameWin::ChangeBackgroundColor(COLORREF Color)
{
	CurrentBackgroundColor = Color;
	CurrentBackgroundColorBrush.DeleteObject();
	CurrentBackgroundColorBrush.CreateSolidBrush(Color);
	background_DC.SelectObject(CurrentBackgroundColorBrush);
}

Is there a better way to do this?

Re: Changing the color of a pen or brush on the fly?

Christian Graus5-Jan-07 10:46

Christian Graus

5-Jan-07 10:46

You can't change a brush, you need to create a new one. If this happens often enough, you could build a cache, I guess.

Christian Graus - Microsoft MVP - C++
Metal Musings - Rex and my new metal blog

dt_dll sample of windows platform sdk

jfranzoy5-Jan-07 10:09

jfranzoy

5-Jan-07 10:09

Hi. I am having a problem running the 'dt_dll' of windows platform sdk under windows 2000 SP4. It comes with a replacement ws2_32.dll (winsock2) that makes possible to trace winsock calls.

The problem is that this replacement of ws2_32.dll calls GetModuleHandleExA in kernel32.dll, by kernel32.dll does not have this entry.

Anybody knows what is (version?) the problem ?

Thanks a lot.

Juan Carlos Franzoy

Re: dt_dll sample of windows platform sdk

Dominik Reichl5-Jan-07 11:22

Dominik Reichl

5-Jan-07 11:22

GetModuleHandleEx is only supported on Windows XP and higher, not on Windows 2000 (see here[^]).

Check, if there's a version of the ws2_32.dll replacement available for Windows 2000. If not, you'll need to develop/test it on a machine with Windows XP or higher.

Too many passwords to remember? Try KeePass Password Safe!

whats wrong with this code?

arbster5-Jan-07 9:18

arbster

5-Jan-07 9:18

I'm trying to delete a value inside a specific key. Whats wrong with the example code I've written to do this?

<br />
<br />
HKEY hkey;<br />
	RegOpenKeyEx(HKEY_LOCAL_MACHINE, "SOFTWARE\\Belkin\\Belkin 802.11g Wireless PCI Card\\1.0.0", 0, KEY_SET_VALUE , &hkey);<br />
	RegDeleteValue(HKEY_LOCAL_MACHINE,"test");<br />
	RegCloseKey(hkey);<br />

Michael Dunn5-Jan-07 9:29

Michael Dunn

5-Jan-07 9:29

RegDeleteValue(hkey,"test");

--Mike--
Visual C++ MVP Cool | :cool:

LINKS~! Ericahist | PimpFish | CP SearchBar v3.0 | C++ Forum FAQ

David Crow5-Jan-07 10:07

David Crow

5-Jan-07 10:07

arbster wrote:
Whats wrong with the example code I've written to do this?

What's wrong is that you are not looking at any return values. Functions return a value for a reason.

"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15

"Judge not by the eye but by the heart." - Native American Proverb

Cristian Amarie5-Jan-07 20:56

Cristian Amarie

5-Jan-07 20:56

... and even wronger is the missing usage of _T() for string arguments.

"My god... we're all gonna die!
Control yourself, general."

Stephen Hewitt7-Jan-07 11:48

Stephen Hewitt

7-Jan-07 11:48

Thats not wrong if you're not concerned with Unicode.

Steve

Cristian Amarie7-Jan-07 20:16

Cristian Amarie

7-Jan-07 20:16

True, but is quite rare the code that escapes from Unicode today...

Nuclear launch detected

Enabling and Diabling a Control

Hamid_RT5-Jan-07 18:55

Hamid_RT

5-Jan-07 18:55

You opend your key so you must use of hkey on the RegDeleteValue

WhiteSky

celllllllll5-Jan-07 8:07

celllllllll

5-Jan-07 8:07

Hi All,

I have two ComboBox controls
{A(it has items like A1, A2 and A3)and
B (B has B1, B2 and B3)}
and one spin control (Z).

Now, my task is that when from control A, A1 is selected then full control B should be diabled. And for all others A2 and A3, B should get enabled.

This is how my code is:

m_CtrlA.SetCurSel(0);<br />
	m_CtrlB.ResetContent();<br />
	if (m_CtrlA.GetCurSel() == A1)<br />
	{<br />
		m_CtrlB.EnableWindow(FALSE);		<br />
		m_Spin.SetRange(0,1000);			<br />
	}<br />
<br />
	else<br />
	{<br />
		m_CtrlB.EnableWindow(TRUE);<br />
	}<br />

So, the problem is what this code is doing is that it is disabling the full m_CtrlB for every case. But I want to disable it for A1 only.

I would really appreciate if someone could help me.

Thanks a lot in advance

C++Prog

Eytukan5-Jan-07 8:19

5-Jan-07 8:19

Assuming, A1 is of type int and it's value is 0, you should remove
m_CtrlA.SetCurSel(0);. because it sets the selection back to 0th item A1 and hence making the if condition useless.

:Gong: 歡迎光臨吐西批 :Gong:

jeron15-Jan-07 8:19

jeron1

5-Jan-07 8:19

In the if statement, A1 is used. What is A1 defined as?

m_CtrlA.SetCurSel(0);<br />
m_CtrlB.ResetContent();<br />
if (m_CtrlA.GetCurSel() == A1)

if it's not 0 then this will never be equal, because you set the current selection to 0 before the if statement is executed.

celllllllll5-Jan-07 8:28

celllllllll

5-Jan-07 8:28

Thanks for the quick response.

A1 is define as:

#define A1 (0)

So, its value is Zero.

And yes I should get rid of

m_CtrlA.SetCurSel(0);

C++Prog

Eytukan5-Jan-07 8:36

5-Jan-07 8:36

celllllllll wrote:

And yes I should get rid of

m_CtrlA.SetCurSel(0);

C++Prog

You should get rid of m_CtrlA.SetCurSel(0); and C++ Programming ? Roll eyes | :rolleyes:

just kidding.

:Gong: 歡迎光臨吐西批 :Gong:

hiding variables

swjam5-Jan-07 7:37

swjam

5-Jan-07 7:37

say a member function
void MyClass::memFx(int a)
{
int a;
a = 25

cout << "a: " << a << endl;
}

if I call the fx with parameter 5 what will display? what are the other rules of hiding variables? sorry i need your help as I have no compiler with me atm.
thx.

Eytukan5-Jan-07 7:52

5-Jan-07 7:52

This would give a redefinition error since you have a already in the function parameter. But hiding variables? can you explain it better?

:Gong: 歡迎光臨吐西批 :Gong:

C^hris L^osinger5-Jan-07 11:10

C^hris L^osinger

5-Jan-07 11:10

VuNic wrote:
This would give a redefinition error since you have a already in the function parameter.

a small modification, and it will compile fine:

void memFx(int a)
{
	{
	   int a;
	   a = 25;
		
	   cout << "a: " << a << endl ;
	}
}

that's variable hiding. the 'a' inside the brackets hides the 'a' from the containing scope, and so the function always outputs 25.

inner scope hides outer scope.

i'm not sure what all the rules are, though.

image processing toolkits | batch image processing | blogging

Eytukan5-Jan-07 16:45

5-Jan-07 16:45

"Variable hiding"- Just learnt. Thanks Chris. Smile | :)

:Gong: 歡迎光臨吐西批 :Gong:

S Douglas7-Jan-07 0:24

S Douglas

7-Jan-07 0:24

Chris Losinger wrote:
that's variable hiding. the 'a' inside the brackets hides the 'a' from the containing scope, and so the function always outputs 25.

inner scope hides outer scope.

So what exactly is the purpose of this part of the language? Or in what circumstance would it be used?

I'd love to help, but unfortunatley I have prior commitments monitoring the length of my grass. :Andrew Bleakley:

C^hris L^osinger7-Jan-07 4:35

C^hris L^osinger

7-Jan-07 4:35

S Douglas wrote:
Or in what circumstance would it be used?

i've always used it accidentally. i don't know why anyone would want to use it on-purpose.

image processing toolkits | batch image processing | blogging