How to draw image on a window?
#include <windows.h>
#include <string.h>
HBITMAP hBitmap, hOldBitmap;
HDC hdc, hdcMem;
BITMAP bm;
HINSTANCE hI;
PAINTSTRUCT ps;
RECT rect;
RECT rc;
LRESULT CALLBACK WindowProcedure(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
switch (msg)
{
case WM_CREATE:
hBitmap = (HBITMAP)LoadImage(hI, "1.bmp", IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE);
GetObject(hBitmap, sizeof(BITMAP), &bm);
hdc = GetDC(hWnd);
hdcMem = CreateCompatibleDC(hdc);
hOldBitmap = SelectBitmap(hdcMem, hBitmap);
ReleaseDC(hWnd, hdc);
return 0;
case WM_LBUTTONDOWN:
//for dragging not only by the title, but also by any part of the window
ReleaseCapture();
SendMessage(hWnd, 0xA1, 2, 0);
break;
case WM_PAINT:
hdc=BeginPaint(hWnd,&ps);
//overlay image with stretching to fit the window
GetClientRect(hWnd,&rect);
SetStretchBltMode(hdc, STRETCH_HALFTONE);
StretchBlt(hdc,0,0,rect.right,rect.bottom,
hdcMem,0,0,bm.bmWidth,bm.bmHeight,SRCCOPY);
EndPaint(hWnd,&ps);
break;
case WM_DESTROY:
PostQuitMessage(0);
DeleteDC(hdcMem);
DeleteObject(hBitmap);
DeleteObject(hOldBitmap);
break;
}
return DefWindowProc(hWnd, msg, wParam, lParam);
}
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPInst, LPSTR lpCmdLine, int nCmdShow)
{
//copying a pointer to a running application instance (module)
hI=hInstance;
WNDCLASS wc;
wc.style = CS_HREDRAW | CS_VREDRAW;
wc.lpfnWndProc = WindowProcedure;
wc.hInstance = hInstance;
wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.hbrBackground = (HBRUSH) GetStockObject(LTGRAY_BRUSH);
wc.lpszClassName = "test_class";
wc.lpszMenuName = NULL;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
RegisterClass(&wc);
HWND hWnd = CreateWindow(wc.lpszClassName, "Image Window",
//window with title (overlapping window)
WS_OVERLAPPEDWINDOW,
//window without title
//WS_VISIBLE | WS_POPUP | WS_SYSMENU | WS_CLIPSIBLINGS | WS_CLIPCHILDREN,
CW_USEDEFAULT, CW_USEDEFAULT, 500, 500, NULL, NULL, hInstance, NULL);
ShowWindow(hWnd, SW_SHOW);
UpdateWindow(hWnd);
MSG msg;
while(GetMessage (&msg, NULL, 0, 0))
{
DispatchMessage (&msg);
TranslateMessage (&msg);
}
UnregisterClass(wc.lpszClassName, hInstance);
return (int) msg.wParam;
}
void LoadScreen(HWND hWnd) {
RECT rect;
HDC hdc = GetDC(hWnd);
HBRUSH brush = CreatePatternBrush((HBITMAP)LoadImage(NULL, L"file.bmp", IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE));
GetWindowRect(hWnd, &rect);
FillRect(hdc, &rect, brush);
DeleteObject(brush);
ReleaseDC(hWnd, hdc);
}
not exactly sure what is your problem: draw a bitmap on the form, or you would like know how to work with various image formats, or both. Anyways below is an example of how you could load a bitmap and draw it on the form:
HBITMAP hBitmap = NULL;
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
int wmId, wmEvent;
switch (message)
{
<...>
case WM_CREATE:
hBitmap = (HBITMAP)LoadImage(hInst, L"c:\\test.bmp", IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE);
break;
case WM_PAINT:
PAINTSTRUCT ps;
HDC hdc;
BITMAP bitmap;
HDC hdcMem;
HGDIOBJ oldBitmap;
hdc = BeginPaint(hWnd, &ps);
hdcMem = CreateCompatibleDC(hdc);
oldBitmap = SelectObject(hdcMem, hBitmap);
GetObject(hBitmap, sizeof(bitmap), &bitmap);
BitBlt(hdc, 0, 0, bitmap.bmWidth, bitmap.bmHeight, hdcMem, 0, 0, SRCCOPY);
SelectObject(hdcMem, oldBitmap);
DeleteDC(hdcMem);
EndPaint(hWnd, &ps);
break;
case WM_DESTROY:
DeleteObject(hBitmap);
PostQuitMessage(0);
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
}
return 0;
}
LoadImage loads an icon, cursor, animated cursor, or bitmap. Details here
For working with various images formats you can use Windows Imaging Component (see IWICBitmapDecoder) or code from here Loading JPEG and GIF pictures or 3rd party tools like FreeImage or LeadTools
hope this helps, regards