Выбор и отображение картинки

#include <windows.h>
// 
LRESULT CALLBACK DepartComTechWndProc(HWND hWnd, UINT Message, UINT wParam, LONG lParam)
 
{
    HDC hDC, hCompatibleDC;
    PAINTSTRUCT PaintStruct;
    static HANDLE hBitmap;
    HANDLE hOldBitmap;
    RECT Rect;
    BITMAP Bitmap;
    static int nHorizDifference = 0, nVertDifference = 0;
    static int nHorizPosition = 0, nVertPosition = 0;
    // Select the desired processing sequence for
    // Specific message
    switch (Message)
    {
        // eliminated the lack of multiple boot images from a file on disk 
    case WM_CREATE:
        hBitmap = LoadImage(NULL, L"1.bmp", IMAGE_BITMAP,
            0, 0, LR_LOADFROMFILE);
        return 0;
    case WM_PAINT:
        // Handle reports of redrawing the working area of the window
        // Get the device descriptor 
        hDC = BeginPaint(hWnd, &PaintStruct);
        GetObject(hBitmap, sizeof(BITMAP), &Bitmap);
        hCompatibleDC = CreateCompatibleDC(hDC);
        hOldBitmap = SelectObject(hCompatibleDC, hBitmap);
        // Definition of the client area for drawing,
        // Rect structure in the first two dimensions equal to 0, and -
        // Third and fourth - the width and height of the window
        GetClientRect(hWnd, &Rect);
        /*Version without scrolling
        * Copy bitmap compatible with the primary device context with scaling
        StretchBlt(hDC, 0, 0, Rect.right, Rect.bottom, hCompatibleDC, 0, 0, Bitmap.bmWidth,
        Bitmap.bmHeight, SRCCOPY);
        */
        /*Version with scrolling */
        BitBlt(hDC, 0, 0, Rect.right, Rect.bottom, hCompatibleDC,
            nHorizPosition, nVertPosition, SRCCOPY);
        if ((nHorizDifference = (Bitmap.bmWidth - Rect.right))>0)
            SetScrollRange(hWnd, SB_HORZ, 0, nHorizDifference, TRUE);
        else
            SetScrollRange(hWnd, SB_HORZ, 0, 0, TRUE);
        if ((nVertDifference = (Bitmap.bmHeight - Rect.bottom))>0)
            SetScrollRange(hWnd, SB_VERT, 0, nVertDifference, TRUE);
        else
            SetScrollRange(hWnd, SB_VERT, 0, 0, TRUE);
        //Re - do the old bitmap current
        SelectObject(hCompatibleDC, hOldBitmap);
        //Remove compatible context
        DeleteDC(hCompatibleDC);
        // 
//      DrawText(hDC, L"Department of Computer Technology 2016. Vinnitsa", -1, &Rect,
//          DT_SINGLELINE | DT_CENTER | DT_VCENTER);
 
        // Definition of the client area for drawing,
        EndPaint(hWnd, &PaintStruct);
        return 0;
    case WM_VSCROLL:
        switch (LOWORD(wParam))
        {
        case SB_LINEDOWN:
            if (nVertPosition<nVertDifference)
                nVertPosition++;
            break;
        case SB_LINEUP:
            if (nVertPosition>0)
                nVertPosition--;
            break;
        case SB_THUMBTRACK:
            nVertPosition = HIWORD(wParam);
            break;
        }
        SetScrollPos(hWnd, SB_VERT, nVertPosition, TRUE);
        InvalidateRect(hWnd, NULL, TRUE);
        return 0;
    case WM_HSCROLL:
        switch (LOWORD(wParam))
        {
        case SB_LINEDOWN:
            if (nHorizPosition<nHorizDifference)
                nHorizPosition++;
            break;
        case SB_LINEUP:
            if (nHorizPosition>0)
                nHorizPosition--;
            break;
        case SB_THUMBTRACK:
            nHorizPosition = HIWORD(wParam);
            break;
        }
        SetScrollPos(hWnd, SB_HORZ, nHorizPosition, TRUE);
        InvalidateRect(hWnd, NULL, TRUE);
        return 0;
        // Beginning of the destruction of the window operation
        // WM_DESTROY message appears in the message queue at
        // Window is closed
    case WM_DESTROY:
        // 
        DeleteObject(hBitmap);
        // Function PostQuitMessage send window (the data about the window in
        // System) message WM_QUIT, which causes the termination of
        // Processing loop
        PostQuitMessage(0);
        return 0;
    }
 
    // Handle all other messages (the default)
    return DefWindowProc(hWnd, Message, wParam, lParam);
 
}
 
int WINAPI wWinMain(HINSTANCE hInstance,
    HINSTANCE hPrevInstance,
    LPTSTR lpszCmdParam,
    int nCmdShow)
{
    //You need to use WNDCLASSEX
    WNDCLASSEX WndClass;
 
    MSG Msg;// message structure 
    //Use Multi-Byte Character Set 
    HWND hWnd;// Display window handle 
 
    //
    //project/<your project name> properties/configuration properties/general/character set/
    //Use Multi-Byte Character Set
 
    // 
    wchar_t  szClassName[] = L"DepartComTech";
 
    //  WNDCLASSEX
 
    WndClass.cbSize = sizeof(WNDCLASSEX);
 
    WndClass.style = CS_HREDRAW | CS_VREDRAW;
    WndClass.lpfnWndProc = DepartComTechWndProc;
    WndClass.cbClsExtra = 0;
    WndClass.cbWndExtra = 0;
    WndClass.hInstance = hInstance;
    WndClass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    WndClass.hCursor = LoadCursor(NULL, IDC_ARROW);
    WndClass.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
    WndClass.lpszMenuName = NULL;
    WndClass.lpszClassName = szClassName;
 
    WndClass.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
    // 
    // You need to use RegisterClassEx
 
    if (!RegisterClassEx(&WndClass))
    {
        MessageBox(NULL, L"Cannot register class", L"Error", MB_OK);
        return 0;
    }
 
 
 
 
    // You need to use CreateWindowEx
 
    hWnd = CreateWindowEx(WS_EX_CLIENTEDGE, szClassName, L"Windows API. Lab 3",
        WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT, CW_USEDEFAULT,
        CW_USEDEFAULT, CW_USEDEFAULT,
        NULL, NULL,
        hInstance, NULL);
 
    //
 
    if (!hWnd)
 
    {
        MessageBox(NULL, L"Cannot create window", L"Error", MB_OK);
        return 0;
    }
 
    //window display 
    // Display the window on the screen
 
    ShowWindow(hWnd, nCmdShow);
 
    // 
    // 
 
    UpdateWindow(hWnd);
 
    // Cycle of treatment of reports 
 
    while (GetMessage(&Msg, NULL, 0, 0))
    {
        // Translates virtual-key messages into character messages 
 
        TranslateMessage(&Msg);
 
        // Dispatches a message to a window procedure 
 
        DispatchMessage(&Msg);
    }
 
    // 
 
    return Msg.wParam;
 
}

//Header
#include <Windows.h>
 
class Myclass {
 
public:
    WNDCLASSEX WndClass;
    HWND hWnd;// Create a unique identifier
 
    Myclass(HINSTANCE hInstance, UINT Style, LPCTSTR Icon, LPCTSTR IconSm, LPCTSTR Cursor, int Background, LPCWSTR szClassName);
    HWND createWindow(HINSTANCE hInstance, int nCmdShow, LPCWSTR  szClassName, LPCWSTR  Title, DWORD Style);
};
 
 
 
Myclass::Myclass(HINSTANCE hInstance, UINT Style, LPCTSTR Icon, LPCTSTR IconSm, LPCTSTR Cursor, int Background, LPCWSTR szClassName)
{
    WndClass.cbSize = sizeof(WNDCLASSEX);
 
    WndClass.style = CS_HREDRAW | CS_VREDRAW;
    WndClass.hInstance = hInstance;
    WndClass.cbClsExtra = 0;
    WndClass.cbWndExtra = 0;
    WndClass.hInstance = hInstance;
    WndClass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    WndClass.hCursor = LoadCursor(NULL, IDC_ARROW);
    WndClass.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
    WndClass.lpszMenuName = NULL;
    WndClass.lpszClassName = szClassName;
 
    WndClass.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
}
HWND Myclass::createWindow(HINSTANCE hInstance, int nCmdShow, LPCWSTR  szClassName, LPCWSTR  Title, DWORD Style) {
    hWnd = CreateWindowEx(WS_OVERLAPPED, szClassName, L"Author is Vasitynskyi",
        WS_SYSMENU,
        CW_USEDEFAULT, CW_USEDEFAULT,
        CW_USEDEFAULT, CW_USEDEFAULT,
        NULL, NULL,
        hInstance, NULL);
 
    return hWnd;
}