C / C++ / MFC Discussion Boards

Re: Dumb Question. But Can't find an answer

Yusuf5-Mar-09 9:19

Yusuf

5-Mar-09 9:19

what do you think GetRValue, GetGValue and GetBValue returns? that should give you a clue.

Yusuf

Re: Dumb Question. But Can't find an answer

FISH7865-Mar-09 9:24

FISH786

5-Mar-09 9:24

Yes you are right.. I was expecting a long value however I have spent like a good chunk of time. and not sure where i am going wrong..

Hence the heading dunb question...I would first like to be able to display the value of color as a string in a messagebox to see it.

the same routine works fine in Vb and I am trying to migrate it into c++ with some other functions.

Re: Dumb Question. But Can't find an answer

Code-o-mat5-Mar-09 9:22

Code-o-mat

5-Mar-09 9:22

I'm not sure what the problem there is, since that error message you gave is too vague, does this work then:

message.Format(_T("Red: %d, Green: %d, Blue: %d"), (int)GetRValue(color6), (int)GetGValue(color6), (int)GetBValue(color6));

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Life: great graphics, but the gameplay sux. <

Re: Dumb Question. But Can't find an answer

FISH7865-Mar-09 9:47

FISH786

5-Mar-09 9:47

Thank you this works...Is there a way I can display the color6 with long values instead of RGB?

thanks

Re: Dumb Question. But Can't find an answer

Code-o-mat5-Mar-09 10:14

Code-o-mat

5-Mar-09 10:14

How do you mean that?

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Life: great graphics, but the gameplay sux. <

Re: Dumb Question. But Can't find an answer

FISH7865-Mar-09 16:52

FISH786

5-Mar-09 16:52

ok..here...I have this function...
void HoleCard1()
{
POINT Carpt,Point1;
COLORREF color1;
Carpt.x = 513;
Carpt.y = 20;
Point1.x = 90;
Point1.y = 90;
HWND hWndActWnd;
hWndActWnd= WindowFromPoint(Carpt);
HDC ActWndDC = GetDC(hWndActWnd);
HDC MemDC = CreateCompatibleDC(ActWndDC);
BitBlt(MemDC ,0,0,1000,1000,ActWndDC,Carpt.x,Carpt.y,SRCCOPY);
color1 = GetPixel(MemDC,Point1.x,Point1.y);

}
The long value of color1 should be 1381653. How do I know this the same location in vb gives me that value and based on the usage in the last 2 weeks there has been no problems.

However if I multiply the R,G,& B from color1, which to my understanding should also give me the long value. However I get a value of 16581375
but i just want to be sure and not start making up numbers.

I have purposely posted the code just incase I have done something wrong in this function.

Thanks A million.

Re: Dumb Question. But Can't find an answer

Code-o-mat5-Mar-09 22:03

Code-o-mat

5-Mar-09 22:03

I'm not sure what you mean but...getting the colorref from the RGB components isn't done by multiplying the components. COLORREF is a 4 byte value (a long is a 8 byte value if i recall correctly), the first byte of this value (the least significant i believe) represents the red component, the second one represents green and the trird one represents blue. (It might be the other way around, am not sure but the idea is basicly the same) So:

[1 Byre Red][1 Byte Green][1 Byte Blue][1 Byte unused]

If you have the 3 components, 1 byte each you can make a colorref of them like this:
Red | (Green << 8) | (Blue << 16)

You can read about this here[^] too, it probably explains it better than i do.

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Life: great graphics, but the gameplay sux. <

Re: Dumb Question. But Can't find an answer

FISH7866-Mar-09 1:52

FISH786

6-Mar-09 1:52

Nice link to explain on the RGB and GDI. Looks like we are on the same page as to what we thinking multiplying the integer from the byte for all three will give us the long decimal value. However, can you or someone tell me if there is anything wrong with the code i have posted in my previous message.

If there isn't I could try and get the Red, Blue and Green from the Visual Basic application. I am trying to migrate an application into c++ from Visual Basic.

after reading a couple of books and some articles. I thought it would be nice to migrate and learn from my own application.

Thanks a Million for all the help. I really appreciate it.

Re: Dumb Question. But Can't find an answer

Code-o-mat6-Mar-09 2:06

Code-o-mat

6-Mar-09 2:06

I'd like to help but i still don't understand what you mean by "long value should be"... Just note that DCs you get for windows should be released using ReleaseDC[^] and memory DCs you create with CreateCompatibleDc should be destroyed with DeleteDC[^].

Note: i do not know Visual Basic, i used it with some small projects but that was ages ago...

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Life: great graphics, but the gameplay sux. <

Re: Dumb Question. But Can't find an answer

FISH7866-Mar-09 2:16

FISH786

6-Mar-09 2:16

Thanks again. Short of missing the ReleaseDC() and DeleteDC(). There is nothing wrong with that small portion of the function?

Thanks Again.

Re: Dumb Question. But Can't find an answer

Code-o-mat6-Mar-09 2:28

Code-o-mat

6-Mar-09 2:28

Well, first of all, am not sure you can actually query and fiddle with a DC of a window belonging to a different thread than yours, but you probably should not anyways... (WindowFromPoint may return a window handle which does not belong to your process)
Now, you create a memory DC there and blit "onto it", but...by default, a memory DC has a 1 pixel by 1 pixel sized, 1 bits per pixel colordepth bitmap selected into it, so when you call Bitblt, you will blit onto that bitmap which is most likely not what you want. You can use GetPixel on the window DC too, you don't need to BitBlt it to some memory DC. If you DO want to create a copy, you have to use -for example- CreateCompatiblebitmap[^], create a bitmap you want to blit onto with it, select this into your memory DC using SelectObject[^], storing the original bitmap handle SelectObject returns, perform the blitting and whatever you wish to do, then select the original bitmap handle into the memory DC before you destroy it, and then also destroy the buffer if you no longer need it using DeleteObject[^].

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Life: great graphics, but the gameplay sux. <

Re: Dumb Question. But Can't find an answer

FISH7866-Mar-09 2:42

FISH786

6-Mar-09 2:42

Thank you. I think you have hit me with something. I can see where my problem is. Yes I want the window belonging to a different thread. The WindowFromPoint is the handle i am looking for.

However some of the things you have mentioned, I beleive is what Visual Basic is all about handling the internal process.

I guess I will have to read more before i carry on and use up space here.

Any sugetions on good reading articles for GDI's or any of the functions I an using? Please advice.

Thanks A million.

Re: Dumb Question. But Can't find an answer

Code-o-mat6-Mar-09 2:45

Code-o-mat

6-Mar-09 2:45

MSDN[^]

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Life: great graphics, but the gameplay sux. <

Re: Dumb Question. But Can't find an answer

Jonnie White6-Mar-09 3:44

Jonnie White

6-Mar-09 3:44

How about this:

COLORREF Color6;
Color6 = GetPixel(MemDC,Point.x,Point.y);
// display the value of Color6 in a messagebox.
CString str;
str.Format(_T("Color6: %x"),Color6);
::AfxMessageBox(str);

Greetings,

Jonnie

Win32

sarathbabununna5-Mar-09 4:56

sarathbabununna

5-Mar-09 4:56

I am unable to get the Window Client Area Coordinates in Mouse LbuttonDown.
Here I am Converting the Coordinates to String Format.
Problem is arised at Runtime in String varible.
Can u pls Solve the Problem

Re: Win32

Code-o-mat5-Mar-09 6:22

Code-o-mat

5-Mar-09 6:22

"Here i have a variable and there i assign it something and then later somewhere it doesn't work, could you fix it for me?" - would you be able to do it? Give more details (code sniplet would be great, which does NOT mean the whole program...) if you wish for any assistance, please.

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Life: great graphics, but the gameplay sux. <

catching ctreectrl's WM_ERASEBKGND

kitkat120125-Mar-09 4:44

kitkat12012

5-Mar-09 4:44

i'm trying to create this method that erases the background of my ctreectrl by catching the WM_ERASEBKGND in the windproc function

i have this working fine, but when i start erasing the background, i start running into problems

i found out that when i receive the WM_ERASEBKGND message, it doesn't really erase the whole background, just parts of it

like if i collapsed a tree node, only the affected region would be erased, any unaffected areas will be left untouched

my question is, how do i get the rect of this "affected region" so i'd know what area to erase?

what i did before was i took the clientrect and erased everything, but this is bad since the "unaffected region" was also erased and the text on it is not repainted

thanks

Re: catching ctreectrl's WM_ERASEBKGND

Code-o-mat5-Mar-09 5:14

Code-o-mat

5-Mar-09 5:14

Did you use the DC you got with wM_ERASEBKGND?

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Life: great graphics, but the gameplay sux. <

Re: catching ctreectrl's WM_ERASEBKGND

kitkat120125-Mar-09 5:54

kitkat12012

5-Mar-09 5:54

right now i'm using GetDC() on the ctreectrl but i could easily change that to use the one that came from WM_ERASEBKGND

Re: catching ctreectrl's WM_ERASEBKGND

Code-o-mat5-Mar-09 5:57

Code-o-mat

5-Mar-09 5:57

Then do so (there's a HDC in either wParam or lParam, look it up), that DC probably has a clipping region selected in it which will permit any paintsings onto areas which should not be overpainted.

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Life: great graphics, but the gameplay sux. <

Re: catching ctreectrl's WM_ERASEBKGND

kitkat120125-Mar-09 6:04

kitkat12012

5-Mar-09 6:04

cool

works perfect, thanks

one last question though, is there a way to get the rect for that region that updated?

cause i'm drawing bitmaps on the background after erasing and i need to calculate like sizes and positions and stuff for this updated region

thanks

Re: catching ctreectrl's WM_ERASEBKGND

Code-o-mat5-Mar-09 6:11

Code-o-mat

5-Mar-09 6:11

You could use CDC::GetClipBox[^] or CDC::GetBoundsRect[^] for that.

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Life: great graphics, but the gameplay sux. <

Can I make a new view of my document DYNAMICALLY and of a different class than the old view? (SDI Doc/View)

Joseph Marzbani5-Mar-09 3:44

Joseph Marzbani

5-Mar-09 3:44

I have a SDI app with one single view, derived from CView at the execute time. now I want to create a splitter window at run time and make a new view of different class (see CRichEdit). But as I look inside the MSDN:

"In "dynamic" splitters, the views are of the same class, In "static" splitters, the views can be of different classes."

I dislike to have a splitter window initially (that's static). What do you suggest to do?

Thank you masters!

Re: Can I make a new view of my document DYNAMICALLY and of a different class than the old view? (SDI Doc/View)

led mike5-Mar-09 4:16

led mike

5-Mar-09 4:16

You probably want to read this technical note[^]

LeftMouseClk and Hold it?

Software20075-Mar-09 3:36

Software2007

5-Mar-09 3:36

Hello,
I would like to move something on a graph based on Left click mouse. This works fine, but How do I make it keep moving if the left Mmouse is still down, I want it to stop moving only when Left Mouse is up...as if I was dragging it... Do I need a timer to do this, or could this be done in other ways?

Thanks

sft

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