Win32模板程序

#pragma comment(lib,"user32.lib")
#pragma comment(lib,"gdi32.lib")
#include <windows.h>
#include <math.h>

#define NUM		1000
#define TWOPI	(2*3.14159)

LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdLine, int iCmdShow)
{
static TCHAR	szAppName[] = TEXT("SineWave");
HWND			hwnd;
MSG				msg;
WNDCLASS		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	= szAppName;

if (!RegisterClass(&wndclass))
{
MessageBox(NULL, TEXT("Program requires Windows NT!"), szAppName, MB_ICONERROR);
return 0;
}

hwnd = CreateWindow(szAppName, TEXT("Sine Wave Using Polyline"),
WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT, CW_USEDEFAULT,
CW_USEDEFAULT, CW_USEDEFAULT,
NULL, NULL, hInstance, NULL);

ShowWindow(hwnd, iCmdShow);
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 int		cxClient, cyClient;
HDC				hdc;
int				i;
PAINTSTRUCT		ps;
POINT			apt[NUM];

switch (message)
{
case WM_SIZE:
cxClient = LOWORD(lParam);
cyClient = HIWORD(lParam);
return 0;

case WM_PAINT:
hdc = BeginPaint(hwnd, &ps);

MoveToEx(hdc, 0, cyClient/2, NULL);
LineTo(hdc, cxClient, cyClient/2);

for (i = 0; i < NUM; i++)
{
apt[i].x = i*cxClient/NUM;
apt[i].y = (int)(cyClient / 2 * (1-sin(TWOPI * i / NUM)));
}
Polyline(hdc, apt, NUM);
EndPaint(hwnd, &ps);
return 0;
case WM_COMMAND:
return 0;
case WM_CREATE:
return 0;
case WM_DESTROY:
PostQuitMessage(0);
return 0;
}

return DefWindowProc(hwnd, message, wParam, lParam);
}