How do I get the hdc of Wind[4]?

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WinAPI in C. Please no C++!!
I am using this stolen code:(part shown only, nice small plain C)
// create the main window
Wind[0] = CreateWindowEx( WS_EX_CONTROLPARENT,
"TINY_UNICODE","Tiny Unicode Editor",
WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT,0,500,300,NULL,NULL,Inst,NULL);
// buttons
Wind[1] = CreateWindow("BUTTON","Open",
WS_CHILD | WS_VISIBLE | BS_PUSHBUTTON,
2,2,50,25,Wind[0],(HMENU) 1001,Inst,NULL);
Wind[2] = CreateWindow("BUTTON","Save",
WS_CHILD | WS_VISIBLE | BS_PUSHBUTTON,
2,30,50,25,Wind[0],(HMENU) 1002,Inst,NULL);
Wind[3] = CreateWindow("BUTTON","Quit",
WS_CHILD | WS_VISIBLE | BS_FLAT,
2,60,50,25,Wind[0],(HMENU) 1003,Inst,NULL);
// edit window
Wind[4] = CreateWindowEx(WS_EX_CLIENTEDGE,"EDIT",NULL,
WS_CHILD | WS_VISIBLE |
ES_MULTILINE,
60,2,200,200,Wind[0],NULL,Inst,NULL);

Now I want to replace the edit control Wind[4] with a static control to draw graphs using SetPixel(hdc, x, y, z, 0, 0));
For that I need to get the hdc of the window Wind[4].
Please how do I do that?
Thank you
Johan Smit

No I have not solved this myself. I probably asked the follow-up question on the wrong place.
I am unsure how to place follow up questions.

Posted 3-Feb-15 17:59pm

Member 10898871

Updated 3-Feb-15 19:55pm

v2

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4 solutions

Solution 1

See GetDC()[^]. Be sure to call ReleaseDC()[^] when done using it.

/ravi

Posted 3-Feb-15 18:11pm

Ravi Bhavnani

Updated 3-Feb-15 18:13pm

v2

Solution 2

Thank you Ravi.
I don't understand GetDC[^]
When I do GetDC(Wind[4]) I get struct HDC_*hdc = struct HDC_ = int unused *<f701644?>
in the Pelles C debugger, and the pixel are not set anywhere.

Posted 3-Feb-15 19:21pm

Member 10898871

Comments

Deepu S Nair 4-Feb-15 2:01am

Don't post your comment as solution.Instead use 'Have a Question or Comment' link so that corressponding member will get a notification

Solution 4

Thank you Frankie for the advice and the code. It works beautifully.
After some years of developing embedded systems, I thought I knew a bit about C.
Win32 API and GDI is something else however. I am learning.
Best Regards
Johan Smit

Posted 8-Feb-15 20:36pm

Member 10898871

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Frankie-C · Accepted Answer · 2015-02-07T11:14:00

Before drawing in a window I suggest you to read about GDI to have a good understanding of windows graphical interface, or you'll get lost...
To speed here you'll find documentation. Study it carefully and you'll get the solution you are looking for.
Anyway this is a simple code to draw a sinus line on a window:

C++

void GraphSomething(HWND hwnd)
{
	RECT rWin;
	GetClientRect(hwnd, &rWin);		//Get window dimensions

	HDC hDc = GetDC(hwnd);

	HPEN hPen = CreatePen(PS_DASHDOT, 2, RGB(255, 0, 0));

	HPEN hOldPen = SelectObject(hDc, hPen);

	float f = 4.0*3.14 / (float)(rWin.right-rWin.left);

	MoveToEx(hDc, rWin.left, rWin.bottom/2 - ((float)rWin.bottom/2 * sin(0.0)), NULL);

	for (int i=rWin.left; i<rWin.right; i++)
	{
		int pt = (float)rWin.bottom/2 * sin(f * (float)(i));
		LineTo(hDc, i, rWin.bottom/2 - pt);
	}

	DeleteObject(SelectObject(hDc, hOldPen));

	ReleaseDC(hwnd, hDc);
}

How do I get the hdc of Wind[4]?

4 solutions

Solution 1

Solution 3

Solution 2

Solution 4

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