IconDemo.c
#include <windows.h>
#include "resource.h"
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
TCHAR szAppName[] = TEXT("IconDemo");
HWND hwnd;
MSG msg;
WNDCLASS wndcls;
wndcls.style = CS_HREDRAW | CS_VREDRAW;
wndcls.lpfnWndProc = WndProc;
wndcls.cbClsExtra = 0;
wndcls.cbWndExtra = 0;
wndcls.hInstance = hInstance;
wndcls.hIcon = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_ICON));
wndcls.hCursor = LoadCursor(NULL, IDC_ARROW);
wndcls.hbrBackground = GetStockObject(WHITE_BRUSH);
wndcls.lpszMenuName = NULL;
wndcls.lpszClassName = szAppName;
if(!RegisterClass(&wndcls))
{
MessageBox(NULL, TEXT("This program requires Windows NT!"), szAppName, MB_ICONERROR);
return 0;
}
hwnd = CreateWindow(szAppName, TEXT("Icon Demo"), WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT,
NULL, NULL, hInstance, NULL);
ShowWindow(hwnd, nCmdShow);
UpdateWindow(hwnd);
while(GetMessage(&msg, NULL, 0, 0))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
return msg.wParam;
}
LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
static HICON hIcon;
static int cxIcon, cyIcon, cxClient, cyClient;
HDC hdc;
HINSTANCE hInstance;
PAINTSTRUCT ps;
int x, y;
switch(message)
{
case WM_CREATE:
hInstance = ((LPCREATESTRUCT)lParam)->hInstance;
hIcon = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_ICON));
cxIcon = GetSystemMetrics(SM_CXICON);
cyIcon = GetSystemMetrics(SM_CYICON);
return 0;
case WM_SIZE:
cxClient = LOWORD(lParam);
cyClient = HIWORD(lParam);
return 0;
case WM_PAINT:
hdc = BeginPaint(hwnd, &ps);
for(y = 0; y < cyClient; y += cyIcon)
{
for(x = 0; x < cxClient; x += cxIcon)
{
DrawIcon(hdc, x, y, hIcon);
}
}
EndPaint(hwnd, &ps);
return 0;
case WM_DESTROY:
PostQuitMessage(0);
return 0;
}
return DefWindowProc(hwnd, message, wParam, lParam);
}
resource.h
#ifndef RESOURCE_H
#define RESOURCE_H
#define IDI_ICON 8001
#endif
resource.rc
a bitmap file, named IDI_ICON
but the Icon can't be changed.