一，信息

触摸屏信息同鼠标信息，不过只有WM_LBUTTONDOWN，WM_LBUTTONUP， WM_MOUSEMOVE 三种。

二，捕捉函数

BOOL GetMouseMovePoints (PPOINT pptBuf, UINT nBufPoints,

UINT *pnPointsRetrieved);

三，实例

PenTrac.h

#define dim(x) (sizeof(x) / sizeof(x[0]))

struct decodeUINT {                             // Structure associates

    UINT Code;                                  // messages 

                                                // with a function. 

    LRESULT (*Fxn)(HWND, UINT, WPARAM, LPARAM);

}; 

struct decodeCMD {                              // Structure associates

    UINT Code;                                  // menu IDs with a 

    LRESULT (*Fxn)(HWND, WORD, HWND, WORD);     // function.

};

HWND InitInstance (HINSTANCE, LPWSTR, int);

int TermInstance (HINSTANCE, int);

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

LRESULT DoPaintMain (HWND, UINT, WPARAM, LPARAM);

LRESULT DoMouseMain (HWND, UINT, WPARAM, LPARAM);

LRESULT DoDestroyMain (HWND, UINT, WPARAM, LPARAM);

PenTrac.cpp

#include <windows.h>                 // For all that Windows stuff

#include "pentrac.h"                 // Program-specific stuff

const TCHAR szAppName[] = TEXT ("PenTrac");

HINSTANCE hInst;                     // Program instance handle

const struct decodeUINT MainMessages[] = {

    WM_LBUTTONDOWN, DoMouseMain,

    WM_MOUSEMOVE, DoMouseMain,

    WM_DESTROY, DoDestroyMain,

};

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,

                    LPWSTR lpCmdLine, int nCmdShow) {

    MSG msg;

    int rc = 0;

    HWND hwndMain;

    hwndMain = InitInstance (hInstance, lpCmdLine, nCmdShow);

    if (hwndMain == 0)

        return 0x10;

    while (GetMessage (&msg, NULL, 0, 0)) {

        TranslateMessage (&msg);

        DispatchMessage (&msg);

    }

    return TermInstance (hInstance, msg.wParam);

}

HWND InitInstance (HINSTANCE hInstance, LPWSTR lpCmdLine, int nCmdShow) {

    WNDCLASS wc;

    HWND hWnd;

#if defined(WIN32_PLATFORM_PSPC)

    hWnd = FindWindow (szAppName, NULL);

    if (hWnd) {

        SetForegroundWindow ((HWND)(((DWORD)hWnd) | 0x01));    

        return 0;

    }

#endif

    hInst = hInstance;

    wc.style = 0;                             // Window style

    wc.lpfnWndProc = MainWndProc;             // Callback function

    wc.cbClsExtra = 0;                        // Extra class data

    wc.cbWndExtra = 0;                        // Extra window data

    wc.hInstance = hInstance;                 // Owner handle

    wc.hIcon = NULL,                          // Application icon

    wc.hCursor = LoadCursor (NULL, IDC_ARROW);// Default cursor

    wc.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH);

    wc.lpszMenuName =  NULL;                  // Menu name

    wc.lpszClassName = szAppName;             // Window class name

    if (RegisterClass (&wc) == 0) return 0;

    hWnd = CreateWindowEx (WS_EX_NODRAG, szAppName, TEXT ("PenTrac"),

                         WS_VISIBLE | WS_CAPTION | WS_SYSMENU,

                         CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, 

                         CW_USEDEFAULT, NULL, NULL, hInstance, NULL);

    if (!IsWindow (hWnd)) return 0;

    ShowWindow (hWnd, nCmdShow);

    UpdateWindow (hWnd);

    return hWnd;

}

int TermInstance (HINSTANCE hInstance, int nDefRC) {

    return nDefRC;

}

LRESULT CALLBACK MainWndProc (HWND hWnd, UINT wMsg, WPARAM wParam,

                              LPARAM lParam) {

    INT i;

    for (i = 0; i < dim(MainMessages); i++) {

        if (wMsg == MainMessages[i].Code)

            return (*MainMessages[i].Fxn)(hWnd, wMsg, wParam, lParam);

    }

    return DefWindowProc (hWnd, wMsg, wParam, lParam);

}

LRESULT DoMouseMain (HWND hWnd, UINT wMsg, WPARAM wParam, 

                     LPARAM lParam) {

    POINT pt[64];

    POINT ptM;

    UINT i, uPoints = 0;

    HDC hdc;

    ptM.x = LOWORD (lParam);

    ptM.y = HIWORD (lParam);

    hdc = GetDC (hWnd);

    if (wMsg == WM_MOUSEMOVE) {

        if (wParam & MK_SHIFT) 

            GetMouseMovePoints (pt, 64, &uPoints);

        for (i = 0; i < uPoints; i++) {

            pt[i].x /= 4;  // Convert move pts to screen coords

            pt[i].y /= 4;

            MapWindowPoints (HWND_DESKTOP, hWnd, &pt[i], 1);

            SetPixel (hdc, pt[i].x,   pt[i].y, RGB (255, 0, 0));

            SetPixel (hdc, pt[i].x+1, pt[i].y, RGB (255, 0, 0));

            SetPixel (hdc, pt[i].x,   pt[i].y+1, RGB (255, 0, 0));

            SetPixel (hdc, pt[i].x+1, pt[i].y+1, RGB (255, 0, 0));

        }

    }

    SetPixel (hdc, ptM.x, ptM.y, RGB (0, 0, 0));

    SetPixel (hdc, ptM.x+1, ptM.y, RGB (0, 0, 0));

    SetPixel (hdc, ptM.x, ptM.y+1, RGB (0, 0, 0));

    SetPixel (hdc, ptM.x+1, ptM.y+1, RGB (0, 0, 0));

    ReleaseDC (hWnd, hdc);

    Sleep(25);

    return 0;

}

LRESULT DoDestroyMain (HWND hWnd, UINT wMsg, WPARAM wParam,

                       LPARAM lParam) {

    PostQuitMessage (0);

    return 0;

}