VB实现截图、复制、剪切和粘贴功能.doc

ReleaseDC函数释放设备上下文环境（DC）供其他应用程序使用 Private Declare Function ReleaseDC Lib user32 (ByVal hwnd As Long, ByVal hdc As Long) As Long OpenClipboard函数用于打开剪切板 Private Declare Function OpenClipboard Lib user32 (ByVal hwnd As Long) As Long EmptyClipboard函数用于清空剪切板 Private Declare Function EmptyClipboard Lib user32 () As Long SetClipboardData函数用于把数据放到具有指定格式的剪切板，窗口必须是当前剪切板的拥有者，该函数必须在OpenClipboard调用后才可以用 Private Declare Function SetClipboardData Lib user32 (ByVal wFormat As Long, ByVal hMem As Long) As Long SelectObject 函数选择一对象到指定的设备上下文环境中，该新对象替换先前的相同类型的对象。 Private Declare Function SelectObject Lib gdi32 (ByVal hdc As Long, ByVal hObject As Long) As Long DeleteDC 该函数删除指定的设备上下文环境（Dc）。 Private Declare Function DeleteDC Lib gdi32 (ByVal hdc As Long) As Long BitBlt 该函数对指定的源设备环境区域中的像素进行位块（bit_block）转换，以传送到目标设备环境。 Private Declare Function BitBlt Lib gdi32 (ByVal hDestDC As Long, ByVal X As Long, ByVal Y As Long, ByVal nWidth As Long, ByVal nHeight As Long, ByVal hSrcDC As Long, ByVal xSrc As Long, ByVal ySrc As Long, ByVal dwRop As Long) As Long CreateCompatibleDC该函数创建一个与指定设备兼容的内存设备上下文环境（DC）。通过GetDc()获取的HDC直接与相关设备沟通，而本函数创建的DC，则是与内存中的一个表面相关联。 Private Declare Function CreateCompatibleDC Lib gdi32 (ByVal hdc As Long) As Long CreateCompatibleBitmap该函数创建与指定的设备环境相关的设备兼容的位图。 Private Declare Function CreateCompatibleBitmap Lib gdi32 (ByVal hdc As Long, ByVal nWidth As Long, ByVal nHeight As Long) As Long CloseClipboard关闭剪贴板,这使其他窗口能访问剪贴板 Private Declare Function CloseClipboard Lib user32 () As Long CreateDC该函数通过使用指定的名字为一个设备创建设备上下文环境。 Private Declare Function CreateDC Lib gdi32 Alias CreateDCA (ByVal lpDriverName As String, ByVal lpDeviceName As String, ByVal lpOutput As String, lpInitData As Long) As Long Const MAX_TOOLTIP As Integer = 64 Const NIF_ICON = H2 删除图标 Const NIF_MESSAGE = H1 Const NIF_TIP = H4 Const NIM_ADD = H0 添加图标到任务栏提示区 Const NIM_DELETE = H2 Const WM_MOUSEMOVE = H200 Const WM_LBUTTONUP = H202 Const WM_RBUTTONUP = H205 Pr