Dev C++ Просмотр изображений

#include<windows.h>
#include<windowsx.h>
 
 
// Handlers declarations
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
void OnDestroy(HWND);
BOOL OnCreate(HWND, LPCREATESTRUCT);
void OnPaint(HWND);
 
// Global variables
HINSTANCE hInst;
HWND hEditWnd;
char szMainWndClassName[MAX_PATH]="MainWndClassName";
HBITMAP hBitmap, hOldBitmap;
HDC hdcMem;
BITMAP bm;
 
// Main procedure
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE , LPSTR, int){
    hInst=hInstance;
    WNDCLASS wc;
    ZeroMemory(&wc, sizeof(WNDCLASS));
    wc.hInstance=hInstance;
    wc.lpfnWndProc=WndProc;
    wc.lpszClassName="MainWndClassName";
    wc.hCursor=LoadCursor(NULL, IDC_ARROW);
    wc.hIcon=LoadIcon(NULL, IDI_APPLICATION);
    wc.hbrBackground=GetStockBrush(LTGRAY_BRUSH);
    RegisterClass(&wc);
    HWND hMainWnd=CreateWindow(szMainWndClassName, "Viewer", WS_OVERLAPPEDWINDOW
                , 100, -10, 700, 580, HWND_DESKTOP, NULL, hInstance, NULL);
    ShowWindow(hMainWnd, SW_SHOWNORMAL);
    MSG msg;
    while(GetMessage(&msg, NULL, 0, 0)){
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return 0;
}
 
// Handlers definitions
LRESULT CALLBACK WndProc(HWND h, UINT msg, WPARAM wParam, LPARAM lParam){
    switch(msg){
        HANDLE_MSG(h, WM_DESTROY, OnDestroy);
        HANDLE_MSG(h, WM_CREATE, OnCreate);
        HANDLE_MSG(h, WM_PAINT, OnPaint);
        default: return DefWindowProc(h, msg, wParam, lParam);
    }
}
 
void OnDestroy(HWND h){
    DeleteBitmap(hBitmap);
    SelectBitmap(hdcMem, hOldBitmap);
    DeleteDC(hdcMem);
    PostQuitMessage(0);
}
 
BOOL OnCreate(HWND hwnd, LPCREATESTRUCT){
    hBitmap=(HBITMAP)LoadImage(hInst, "c:\\1.bmp", IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE);
    if(!hBitmap)MessageBox(NULL, "LoadImage failed", "Error", 0);
    GetObject(hBitmap, sizeof(BITMAP), &bm);
    HDC hdc=GetDC(hwnd);
    hdcMem=CreateCompatibleDC(hdc);
    hOldBitmap=SelectBitmap(hdcMem, hBitmap);
    ReleaseDC(hwnd, hdc);
    return TRUE;
}
 
void OnPaint(HWND hwnd){
    PAINTSTRUCT ps;
    HDC hdc=BeginPaint(hwnd, &ps);
    BitBlt(hdc, 0, 0, bm.bmWidth, bm.bmHeight, hdcMem, 0, 0, SRCCOPY);
    EndPaint(hwnd, &ps);
}