Thread: Compile error 35: undefined reference to `_CreatePen@12'

Sorry that this is messy, but im under a quickly approaching deadline. I would consolidate the code but I am new to windows programming and I'm not sure whats wrong.

I just would like to know why I cant succesfully compile this code which was provided by our professor. I appreciate any help in getting it to compile and run.

Thank you.

Code:

#include <windows.h>

const char g_szClassName[] = "myWindowClass";

// Step 4: the Window Procedure
LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    
    HDC hDC;
    PAINTSTRUCT Ps;
    HPEN hPen1;
    //HBRUSH hBrush;
    //HFONT  hFont;
    long lfHeight=30;
    RECT rect;
    
    static bool isEllipse = true;
    
    
    static int thickness = 10;
    
    static int red=200;
    static int green=40;
    static int blue=60;
    
    static int die_num1 = 1;
    static int die_num2 = 1;
    
    switch(msg)
    {
        case WM_PAINT:
           
            hDC=BeginPaint(hwnd,&Ps);
            // pens are needed to draw things made with lines
            hPen1 =CreatePen(PS_SOLID, thickness, RGB(red,green,blue));
            
            //hBrush = CreateSolidBrush(RGB(255,0,0)); 
            
            //hFont = CreateFont(lfHeight, 0, 0, 0, 0, TRUE, 0, 0, 0, 0, 0, 0, 0, L"Times New Roman");
            
            SelectObject(hDC, hPen1);
            
            //SelectObject(hDC, hBrush);
            
            //SelectObject(hDC, hFont);
            
            rect.top=520;
            rect.bottom=665;
            rect.left=125;
            rect.right=1025;
            
            //DrawText(hDC,L"Art by Dr. Thomas Fernandez", -1,&rect, DT_WORDBREAK);
            
            /*for(int i=0;i<500;i=i+10)
            {
                DrawTwoColoredLine(hDC,0,i,500,500,RGB(0,255,i/2),RGB(255,0,i/2));
            }
            
            //SelectObject(hDC, hPen);
            
            if(isEllipse)
            {
                Ellipse(hDC, 520, 22, 750, 125);
            }
            
            else
            {
                Rectangle(hDC, 520, 22, 750, 125);
            }
            
            //rCircle(hDC,233,230,210,25,25,250);
            //rCircle(hDC,233,230,140,250,25,250);
            
            //DeleteObject(hFont);
            //DeleteObject(hBrush);
            DeleteObject(hPen1);
            
            EndPaint(hwnd,&Ps);
            break;*/
        
        case WM_CLOSE:
            DestroyWindow(hwnd);
            break;
        
        case WM_CHAR:
            if(wParam=='r')
            {
                red=rand()%256;
                green=rand()%256;
                blue=rand()%256;
                InvalidateRect(hwnd,NULL,true);
            }
            else if(wParam==' ')
            {
                die_num1=rand()%6+1;
                die_num2=rand()%6+1;
            }
    break;
        case WM_DESTROY:
            PostQuitMessage(0);
        break;
        default:
            return DefWindowProc(hwnd, msg, wParam, lParam);
    }
    return 0;
}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
    LPSTR lpCmdLine, int nCmdShow)
{
    WNDCLASSEX wc;
    HWND hwnd;
    MSG Msg;

    //Step 1: Registering the Window Class
    wc.cbSize        = sizeof(WNDCLASSEX);
    wc.style         = 0;
    wc.lpfnWndProc   = WndProc;
    wc.cbClsExtra    = 0;
    wc.cbWndExtra    = 0;
    wc.hInstance     = hInstance;
    wc.hIcon         = LoadIcon(NULL, IDI_APPLICATION);
    wc.hCursor       = LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
    wc.lpszMenuName  = NULL;
    wc.lpszClassName = g_szClassName;
    wc.hIconSm       = LoadIcon(NULL, IDI_APPLICATION);

    if(!RegisterClassEx(&wc))
    {
        MessageBox(NULL, "Window Registration Failed!", "Error!",
            MB_ICONEXCLAMATION | MB_OK);
        return 0;
    }

    // Step 2: Creating the Window
    hwnd = CreateWindowEx(
        WS_EX_CLIENTEDGE,
        g_szClassName,
        "The title of my window",
        WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT, CW_USEDEFAULT, 240, 120,
        NULL, NULL, hInstance, NULL);

    if(hwnd == NULL)
    {
        MessageBox(NULL, "Window Creation Failed!", "Error!",
            MB_ICONEXCLAMATION | MB_OK);
        return 0;
    }

    ShowWindow(hwnd, nCmdShow);
    UpdateWindow(hwnd);

    // Step 3: The Message Loop
    while(GetMessage(&Msg, NULL, 0, 0) > 0)
    {
        TranslateMessage(&Msg);
        DispatchMessage(&Msg);
    }
    return Msg.wParam;
}

You need to be sure you're linking with gdi32.lib, according to MSDN.

Im not sure what that means but would it have something to do with the fact that I'm using the Netbeans IDE and cygwin compiler?

Thank you for your help so far. Does anyone know the way to link the file in Visual C++ 2008 Express?