Thread: Need a little help with GetPixel()

Hi I am trying to experiment with GetPixel() to see if I can get a color output. So far this is my code:

Code:

#include <iostream>
#include <Windows.h>

using namespace std;

int main()
{
    COLORREF lcolor = 0;
    int lx = 653, ly = 347;

    HWND hwnd = FindWindow(0, L"Hearts");
    HDC hdc = GetWindowDC(hwnd); 

    Sleep(5000); 

    lcolor=GetPixel(hdc,lx,ly);

    int r = GetRValue ( lcolor );
    int g = GetGValue ( lcolor );
    int b = GetBValue ( lcolor );

    cout << r << endl;
    cout << g << endl;
    cout << b << endl;

    return 0;
}

As you can see I am trying to get different color values from the Hearts game included in Windows 7. However, whenever I run my program, I always get RGB values such as 255 255 255 for red, green, and blue respectively. With the coordinates x = 653, y = 347, certainly it would be very hard to miss the large mass of green in the background.

What am I doing wrong? Thank you for your time.

NOTE: The 5 seconds delay is to give me time to switch to the Hearts program in full screen.

IDE used is Visual Studio 2010. OS is Windows 7.

Looking at the the docs, sounds like you're getting CLR_INVALID. It sounds like there could be a couple things (need to be in a clipping region, need to be in a bitmap).