COLORREF with Qt

R3dp1ll

hello,

I have a problem with the use of COLORREF with Qt.

I made this piece of code on visual studio:

#include <windows.h>
#include <stdio.h>

int main()
{
	Sleep(2000);
	//create the coords
	int xPixelColor = 829;
	int yPixelColor = 1021;

	//flash the pixel color and stock it
	HDC dc = GetDC(NULL);
	COLORREF color = GetPixel(dc, xPixelColor, yPixelColor);
	ReleaseDC(NULL, dc);

	// find RGV
	int red = GetRValue(color);
	int green = GetGValue(color);
	int blue = GetBValue(color);

	std::cout << red << green << blue;
}

it works perfectly.

Copy pasted under Qt and hop it does not compile anymore: "undefined reference to `_imp_GetPixel@12'
Yet I put the same includes ...
There, I'm lost, an idea?

Christian Ehrlicher

According to MSDN ( https://docs.microsoft.com/en-us/windows/desktop/api/wingdi/nf-wingdi-getpixel ) GetPixel is available in Gdi32.lib so you should link to gdi32.lib ( http://doc.qt.io/qt-5/qmake-variable-reference.html#libs )

R3dp1ll

Yeah it was simple... I thought Qt had the same basic library tools as VS.

And now, it works. thank you.