Windows Mobile 编程 (Win32) - 画正弦波

主要演示如何使用Ployline()函数。

#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, LPTSTR lpCmdLine, int nCmdShow)
{
    static TCHAR szAppName[] = TEXT("SineWave");
    HWND     hwnd;
    MSG      msg;
    WNDCLASS wc;

    // Set up the window class description
    ZeroMemory(&wc, sizeof(wc));
    wc.style         = CS_HREDRAW | CS_VREDRAW;
    wc.lpfnWndProc   = WndProc;
    wc.hInstance     = hInstance;
    wc.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
    wc.lpszClassName = szAppName;

    if (!RegisterClass(&wc))
    {
        MessageBox(NULL, TEXT("RegisterClass() failed!"), szAppName, MB_ICONERROR);
        return 0;
    }

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

    if (hwnd == NULL)
    {
        MessageBox(NULL, TEXT("CreateWindow() failed!"), szAppName, MB_ICONERROR);
        return 0;
    }

    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 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);
        return 0;

    case WM_DESTROY:
        PostQuitMessage(0);
        return 0;
    }

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