///////////////////////////////////////////////////////////////////////////// // Name: dc // Purpose: topic overview // Author: wxWidgets team // RCS-ID: $Id$ // Licence: wxWindows license ///////////////////////////////////////////////////////////////////////////// /*! @page dc_overview Device context overview Classes: #wxBufferedDC, #wxBufferedPaintDC, #wxDC, #wxPostScriptDC, #wxMetafileDC, #wxMemoryDC, #wxPrinterDC, #wxScreenDC, #wxClientDC, #wxPaintDC, #wxWindowDC. A wxDC is a @e device context onto which graphics and text can be drawn. The device context is intended to represent a number of output devices in a generic way, with the same API being used throughout. Some device contexts are created temporarily in order to draw on a window. This is @true of #wxScreenDC, #wxClientDC, #wxPaintDC, and #wxWindowDC. The following describes the differences between these device contexts and when you should use them. @b wxScreenDC. Use this to paint on the screen, as opposed to an individual window. @b wxClientDC. Use this to paint on the client area of window (the part without borders and other decorations), but do not use it from within an #wxPaintEvent. @b wxPaintDC. Use this to paint on the client area of a window, but @e only from within a #wxPaintEvent. @b wxWindowDC. Use this to paint on the whole area of a window, including decorations. This may not be available on non-Windows platforms. To use a client, paint or window device context, create an object on the stack with the window as argument, for example: @code void MyWindow::OnMyCmd(wxCommandEvent& event) { wxClientDC dc(window); DrawMyPicture(dc); } @endcode Try to write code so it is parameterised by wxDC - if you do this, the same piece of code may write to a number of different devices, by passing a different device context. This doesn't work for everything (for example not all device contexts support bitmap drawing) but will work most of the time. */