/*
   Windows2000の半透明ウインドウ

      2000/ 2/ 2  宍戸　輝光
*/

#include <windows.h>

typedef DWORD (WINAPI *FWINLAYER)(HWND hwnd,DWORD crKey,BYTE bAlpha,DWORD dwFlags);
#define WS_EX_LAYERED 0x80000

LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM);
HINSTANCE hInst;
HWND hwMain;

FWINLAYER pfWin;

HINSTANCE hDll=NULL;

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
                    PSTR szCmdLine, int iCmdShow){

	MSG  msg;
	WNDCLASSEX  wndclass ;

	hInst=hInstance; /* プロセスのハンドルを保存 */

	hDll=LoadLibrary("user32.dll"); /* DLLから関数アドレス取得 */
    pfWin=(FWINLAYER)GetProcAddress(hDll,"SetLayeredWindowAttributes");

	wndclass.cbSize        = sizeof(wndclass);
	wndclass.style         = CS_HREDRAW | CS_VREDRAW;
	wndclass.lpfnWndProc   = WndProc;
	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 = "CWindow";
	wndclass.hIconSm       = LoadIcon (NULL, IDI_APPLICATION);

	RegisterClassEx(&wndclass);

	hwMain=CreateWindowEx(WS_EX_LAYERED,"CWindow",NULL,WS_OVERLAPPEDWINDOW,
               CW_USEDEFAULT,CW_USEDEFAULT,320,320,
               NULL,NULL,hInstance,NULL);

	if (pfWin!=NULL) /* SetLayeredWindowAttributes実行 */
		pfWin(hwMain,0,128,2);

	ShowWindow(hwMain,iCmdShow); /* ウインドウを表示 */
	UpdateWindow (hwMain);        /* 再描画 */

	while (GetMessage (&msg,NULL,0,0)) { /* メッセージループ */

		TranslateMessage(&msg);
		DispatchMessage(&msg);

	}

	return msg.wParam ;

}

LRESULT CALLBACK WndProc (HWND hwnd, UINT iMsg, WPARAM wParam, LPARAM lParam) {

	switch (iMsg) {

		case WM_DESTROY :

			PostQuitMessage(0);
			return 0;

	}

	return DefWindowProc (hwnd, iMsg, wParam, lParam) ;

}