剪贴簿的使用

初级的剪贴簿使用方法：

#include <windows.h>
#include "resource.h"

LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
#ifdef UNICODE
#define CF_TCHAR CF_UNICODETEXT
TCHAR szDefaultText[] = TEXT("Default Text-Unicode Version");
TCHAR szCaption[] = TEXT("Clipborad Text Transfers-unicode");
#else
#define CF_TCHAR CF_TEXT
TCHAR szDefaultText[] = TEXT("Default Text-ANSI Version");
TCHAR szCaption[] = TEXT("Clipboard Text Transfer-ANSI");
#endif

int WINAPI WinMain(HINSTANCE hInstance,
                 HINSTANCE hPrevInstance,
                 PSTR szCmdLine,
                 int iCmdShow) {
    static TCHAR szAppName[] = TEXT("ClipText");
    HACCEL hAccel;
    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 = szAppName;
    wndclass.lpszClassName = szAppName;
    
    if(!RegisterClass(&wndclass)) {
        MessageBox(NULL,
            TEXT("Register failure!"),
            szAppName,
            MB_ICONERROR);
        return 0;
    }
    
    hwnd = CreateWindow(szAppName,
         szCaption,
             WS_OVERLAPPEDWINDOW,
             CW_USEDEFAULT,
             CW_USEDEFAULT,
             CW_USEDEFAULT,
             CW_USEDEFAULT,
             NULL,
             NULL,
             hInstance,
             NULL);
    
    ShowWindow(hwnd, iCmdShow);
    UpdateWindow(hwnd);
    
    hAccel = LoadAccelerators(hInstance, szAppName);
    while(GetMessage(&msg, NULL, 0, 0)) {
        if(!TranslateAccelerator(hwnd, hAccel, &msg)) {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    }
    return msg.wParam;
}

LRESULT CALLBACK WndProc(HWND hwnd,
                         UINT message,
                         WPARAM wParam,
                         LPARAM lParam) {
    static PTSTR pText;
    BOOL bEnable;
    HGLOBAL hGlobal;
    HDC hdc;
    PTSTR pGlobal;
    PAINTSTRUCT ps;
    RECT rect;
    
    switch(message) {
    case WM_CREATE:
        SendMessage(hwnd, WM_COMMAND, IDM_EDIT_RESET, 0);
        return 0;
        
    case WM_INITMENUPOPUP:
        EnableMenuItem((HMENU)wParam, IDM_EDIT_PASTE,
            IsClipboardFormatAvailable(CF_TCHAR)?
MF_ENABLED : MF_GRAYED);
        bEnable = pText ? MF_ENABLED : MF_GRAYED;
        
        EnableMenuItem((HMENU)wParam, IDM_EDIT_CUT, bEnable);
        EnableMenuItem((HMENU)wParam, IDM_EDIT_COPY, bEnable);
        EnableMenuItem((HMENU)wParam, IDM_EDIT_CLEAR, bEnable);
        break;
        
    case WM_COMMAND:
        switch(LOWORD(wParam)) {
        case IDM_EDIT_PASTE:
            OpenClipboard(hwnd);
            if(hGlobal = GetClipboardData(CF_TCHAR)) {
                pGlobal = GlobalLock(hGlobal);
                if(pText) {
                    free(pText);
                    pText = NULL;
                }
                pText = malloc(GlobalSize(hGlobal));
                lstrcpy(pText, pGlobal);
                InvalidateRect(hwnd, NULL, TRUE);
            }
            CloseClipboard();
            return 0;
            
        case IDM_EDIT_CUT:
        case IDM_EDIT_COPY:
            if(!pText)
                return 0;
            
            hGlobal = GlobalAlloc(GHND | GMEM_SHARE,
                (lstrlen(pText) + 1) *
                sizeof(TCHAR));
            pGlobal = GlobalLock(hGlobal);
            lstrcpy(pGlobal, pText);
            GlobalUnlock(hGlobal);
            
            OpenClipboard(hwnd);
            EmptyClipboard();
            SetClipboardData(CF_TCHAR, hGlobal);
            CloseClipboard();
            
            if(LOWORD(wParam) == IDM_EDIT_COPY)
                return 0;
        case IDM_EDIT_CLEAR:
            if(pText) {
                free(pText);
                pText = NULL;
            }
            InvalidateRect(hwnd, NULL, TRUE);
            return 0;
            
        case IDM_EDIT_RESET:
            if(pText) {
                free(pText);
                pText = NULL;
            }
            pText = malloc((lstrlen(szDefaultText) + 1) *
                sizeof(TCHAR));
            lstrcpy(pText, szDefaultText);
            InvalidateRect(hwnd, NULL, TRUE);
            return 0;
        }
        break;
        
        case WM_PAINT:
            hdc = BeginPaint(hwnd, &ps);
            GetClientRect(hwnd, &rect);
            
            if(pText != NULL)
                DrawText(hdc, pText, -1, &rect, DT_EXPANDTABS
                | DT_WORDBREAK);
            EndPaint(hwnd, &ps);
            return 0;
            
        case WM_DESTROY:
            if(pText)
                free(pText);
            PostQuitMessage(0);
            return 0;
    }
    return DefWindowProc(hwnd, message, wParam, lParam);
                         }