Creazione di penne e pennelli colorati

Anche se è possibile specificare qualsiasi colore per una penna durante la creazione, il sistema usa solo i colori disponibili nel dispositivo. Questo significa che il sistema usa il colore di corrispondenza più vicino quando si rende conto della penna per il disegno. Quando si creano pennelli, il sistema genera un colore dithered se si specifica un colore che il dispositivo non supporta. In entrambi i casi, è possibile usare la macro RGB per specificare un colore durante la creazione di una penna o un pennello.

LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    int wmId, wmEvent;
    PAINTSTRUCT ps;
    HDC hdc;
    RECT clientRect;
    RECT textRect;
    HRGN bgRgn;
    HBRUSH hBrush;
    HPEN hPen;


    switch (message)
    {
    
    case WM_PAINT:
        {
        hdc = BeginPaint(hWnd, &ps);
        
        // Fill the client area with a brush
        GetClientRect(hWnd, &clientRect);
        bgRgn = CreateRectRgnIndirect(&clientRect);
        hBrush = CreateSolidBrush(RGB(200,200,200));
        FillRgn(hdc, bgRgn, hBrush);

        
        hPen = CreatePen(PS_DOT,1,RGB(0,255,0));
        SelectObject(hdc, hPen);
        SetBkColor(hdc, RGB(0,0,0));
        Rectangle(hdc, 10,10,200,200);
        
        // Text caption
        SetBkColor(hdc, RGB(255,255,255));
        SetRect(&textRect, 10, 210, 200,200);
        DrawText(hdc,TEXT("PS_DOT"),-1,&textRect, DT_CENTER | DT_NOCLIP);

        
        hPen = CreatePen(PS_DASHDOTDOT,1,RGB(0,255,255));
        SelectObject(hdc, hPen);
        SetBkColor(hdc, RGB(255,0,0));
        SelectObject(hdc,CreateSolidBrush(RGB(0,0,0)));
        Rectangle(hdc, 210,10,400,200);
        
        // Text caption
        SetBkColor(hdc, RGB(255,200,200));
        SetRect(&textRect, 210, 210, 400,200);
        DrawText(hdc,TEXT("PS_DASHDOTDOT"),-1,&textRect, DT_CENTER | DT_NOCLIP);
        

        hPen = CreatePen(PS_DASHDOT,1,RGB(255,0,0));
        SelectObject(hdc, hPen);
        SetBkColor(hdc, RGB(255,255,0));
        SelectObject(hdc,CreateSolidBrush(RGB(100,200,255)));
        Rectangle(hdc, 410,10,600,200);
        
        // Text caption
        SetBkColor(hdc, RGB(200,255,200));
        SetRect(&textRect, 410, 210, 600,200);
        DrawText(hdc,TEXT("PS_DASHDOT"),-1,&textRect, DT_CENTER | DT_NOCLIP);
        

        // When fnPenStyle is PS_SOLID, nWidth may be more than 1.
        // Also, if you set the width of any pen to be greater than 1, 
        // then it will draw a solid line, even if you try to select another style.
        hPen = CreatePen(PS_SOLID,5,RGB(255,0,0));
        SelectObject(hdc, hPen);
        // Setting the background color doesn't matter 
        // when the style is PS_SOLID
        SetBkColor(hdc, RGB(255,255,255));
        SelectObject(hdc,CreateSolidBrush(RGB(200,100,50)));
        Rectangle(hdc, 10,300,200,500);
        
        // Text caption
        SetBkColor(hdc, RGB(200,200,255));
        SetRect(&textRect, 10, 510, 200,500);
        DrawText(hdc,TEXT("PS_SOLID"),-1,&textRect, DT_CENTER | DT_NOCLIP);
    
        hPen = CreatePen(PS_DASH,1,RGB(0,255,0));
        SelectObject(hdc, hPen);
        SetBkColor(hdc, RGB(0,0,0));
        SelectObject(hdc,CreateSolidBrush(RGB(200,200,255)));
        Rectangle(hdc, 210,300,400,500);
        
        // Text caption
        SetBkColor(hdc, RGB(255,255,200));
        SetRect(&textRect, 210, 510, 400,200);
        DrawText(hdc,TEXT("PS_DASH"),-1,&textRect, DT_CENTER | DT_NOCLIP);

        hPen = CreatePen(PS_NULL,1,RGB(0,255,0));
        SelectObject(hdc, hPen);
        // Setting the background color doesn't matter 
        // when the style is PS_NULL
        SetBkColor(hdc, RGB(0,0,0));
        SelectObject(hdc,CreateSolidBrush(RGB(255,255,255)));
        Rectangle(hdc, 410,300,600,500);
        
        // Text caption
        SetBkColor(hdc, RGB(200,255,255));
        SetRect(&textRect, 410, 510, 600,500);
        DrawText(hdc,TEXT("PS_NULL"),-1,&textRect, DT_CENTER | DT_NOCLIP);
        
        
        // Clean up
        DeleteObject(bgRgn);
        DeleteObject(hBrush);
        DeleteObject(hPen);

        GetStockObject(WHITE_BRUSH);
        GetStockObject(DC_PEN);

        EndPaint(hWnd, &ps);
        break;
        }
    

    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    default:
        return DefWindowProc(hWnd, message, wParam, lParam);
    }
    return 0;
}