Wip Wip - 14 days ago 5
C Question

How to add gdi32.lib correctly from within the file?

I'm currently having a problem with including the

gdi32.lib
in my C project on windows. The error occurs in the following code segment:

#include <windows.h>
#pragma comment(lib, "kernel32.lib")
#pragma comment(lib, "user32.lib")
#pragma comment(lib, "gdi32.lib")
int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow) {
WNDCLASSEX wcx;
wcx.hbrBackground = CreateSolidBrush(0x000000);
....
}


When I compile with the
-lgdi32
option, everything works just as expected, whereas I get a compiling error with the following command:

C:\projects\cpp>c++ project.cpp
C:\Users\LUKASW~1\AppData\Local\Temp\ccSKc5qg.o:project.cpp:(.text+0xe0):
undefined reference to `__imp_CreateSolidBrush'
collect2.exe: error: ld returned 1 exit status


Is there a way to link the libraries directly in a file rather than passing it to the compiler every time?



Here is the stripped down version for debugging:

#include <windows.h>
#pragma comment(lib, "kernel32.lib")
#pragma comment(lib, "user32.lib")
#pragma comment(lib, "gdi32.lib")

static char szWindowClass[] = "debugging";
static char szTitle[] = "gdi32.lib test";

HINSTANCE hInst;
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);

void GetDesktopResolution(int& w, int& h) {
RECT desktop;
GetWindowRect(GetDesktopWindow(), &desktop);
w = desktop.right;
h = desktop.bottom;
}

int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow) {
WNDCLASSEX wcx;

wcx.cbClsExtra = 0;
wcx.cbSize = sizeof(WNDCLASSEX);
wcx.cbWndExtra = 0;
wcx.hbrBackground = CreateSolidBrush(0x000000);
wcx.hCursor = LoadCursor(NULL, IDC_ARROW);
wcx.hIcon = LoadIcon(hInst, IDI_APPLICATION);
wcx.hIconSm = LoadIcon(wcx.hInstance, IDI_APPLICATION);
wcx.hInstance = hInst;
wcx.lpfnWndProc = WndProc;
wcx.lpszClassName = szWindowClass;
wcx.lpszMenuName = NULL;
wcx.style = CS_HREDRAW | CS_VREDRAW;

RegisterClassEx(&wcx);

int x, y,
w = 600,
h = 600;
GetDesktopResolution(x, y);

HWND hWnd = CreateWindowEx(WS_EX_APPWINDOW, szWindowClass, szTitle, WS_POPUP, (x - w) / 2, (y - h) / 2, w, h, NULL, NULL, hInst, NULL);

ShowWindow(hWnd, nCmdShow);
UpdateWindow(hWnd);

MSG msg;
while(GetMessage(&msg, NULL, 0, 0)) {
TranslateMessage(&msg);
DispatchMessage(&msg);
}

return (int) msg.wParam;
}

LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam) {
switch (message) {
case WM_PAINT:
// empty
break;
case WM_DESTROY:
PostQuitMessage(0);
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
break;
}

return 0;
}

Answer

#pragma comment(lib, ...) is an MS Visual C/C++ pragma. You are using MinGW, which doesn't support that directive.

From what I read on this question, GCC and G++ don't have an equivalent pragma, so you will have to stick with the -l option.

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