Visual C++ Clipboard

一.使用SetClipboardData 方法赋值

首先用GlobalAlloc方法分配内存

1. GlobalAlloc 分配内存大小
2. GlobalLock 锁定内存
3. 拷贝数据到内存中
4. GlobalUnlock解锁
   

OpenClipboard 和CloseClipboard相对应

char szText[]= "Hello, world"; // ANSI characters
if (::OpenClipboard (m_hWnd)) {
    ::EmptyClipboard ();

    HANDLE hData = ::GlobalAlloc (GMEM_MOVEABLE, ::lstrlen (szText) + 1);
    LPSTR pData = (LPSTR) ::GlobalLock (hData);
    ::lstrcpy (pData, szText);
    ::GlobalUnlock (hData);

    ::SetClipboardData (CF_TEXT, hData);
    ::CloseClipboard ();

二.获取Clipboard数据

GetClipboardData 方法获取
GlobalLock 方法可以转型数据(返回是一个VOID指针)

char szText[MAX_PATH];
if (::OpenClipboard (m_hWnd)) {
    HANDLE hData = ::GetClipboardData (CF_TEXT);
    if (hData != NULL) {
        LPCSTR pData = (LPCSTR) ::GlobalLock (hData);
        if (::lstrlen (pData) < MAX_PATH)
            ::lstrcpy (szText, pData);
        ::GlobalUnlock (hData);
    }
    ::CloseClipboard ();
}

三.Clipboard Formats

不仅仅是字符串复制一个Bitmap图片,

if (::OpenClipboard (m_hWnd)) {
    // Make a copy of the bitmap.
    BITMAP bm;
    CBitmap bitmap;
    CBitmap m_bitmap;
    m_bitmap.LoadBitmap(IDB_BITMAP2);
    m_bitmap.GetObject (sizeof (bm), &bm);
    bitmap.CreateBitmapIndirect (&bm);

    CDC dcMemSrc, dcMemDest;
    dcMemSrc.CreateCompatibleDC (NULL);
    CBitmap* pOldBitmapSrc = dcMemSrc.SelectObject (&m_bitmap);
    dcMemDest.CreateCompatibleDC (NULL);
    CBitmap* pOldBitmapDest = dcMemDest.SelectObject (&bitmap);

    dcMemDest.BitBlt (0, 0, bm.bmWidth, bm.bmHeight, &dcMemSrc,
        0, 0, SRCCOPY);
    HBITMAP hBitmap = (HBITMAP) bitmap.Detach ();

    dcMemDest.SelectObject (pOldBitmapDest);
    dcMemSrc.SelectObject (pOldBitmapSrc);

    // Place the copy on the clipboard.
    ::EmptyClipboard ();
    ::SetClipboardData (CF_BITMAP, hBitmap);
    ::CloseClipboard ();
}

获取复制的Bitmap

if (::OpenClipboard (m_hWnd)) {
    HBITMAP hBitmap = (HBITMAP) ::GetClipboardData (CF_BITMAP);
    if (hBitmap != NULL) {
        // Make a local copy of the bitmap.
    }
    ::CloseClipboard ();
}

四.Private Clipboard Formats

除了内置格式,还可以自定义格式

1. UINT nID = ::RegisterClipboardFormat (_T ("Widget"));
2. ::SetClipboardData (nID, hData);
3. HANDLE hData = ::GetClipboardData (nID);

五.Providing Data in Multiple Formats

可以将多种格式的数据存在Clipboard中

::SetClipboardData (nID, hPrivateData);
::SetClipboardData (CF_BITMAP, hBitmap);
::SetClipboardData (CF_TEXT, hTextData);

六.查询可用Formats

1.判断不同格式(IsClipboardFormatAvailable),注意没用完Clipboard时,不要关闭Clipboard,所以把CloseClipboard放最后

if (::OpenClipboard (m_hWnd)) {
    if (::IsClipboardFormatAvailable (nID)) {
        // Perfect!
    }
    else if (::IsClipboardFormatAvailable (CF_TEXT)) {
        // Not the best, but I'll take it.
    }
    else if (::IsClipboardFormatAvailable (CF_BITMAP)) {
        // Better than nothing.
    }
    ::CloseClipboard ();
}

2.获取后的处理方式同上

if (::OpenClipboard (m_hWnd)) {
    if (::IsClipboardFormatAvailable (CF_TEXT)) {
        HANDLE hData = ::GetClipboardData (CF_TEXT);
        LPCSTR pData = (LPCSTR) ::GlobalLock (hData);
            
    }
    ::CloseClipboard ();
}

参考:MFC Windows程序设计