device context overview

classes: wxbuffereddc, wxbufferedpaintdc, wxdc, wxpostscriptdc, wxmetafiledc, wxmemorydc, wxprinterdc, wxscreendc, wxclientdc, wxpaintdc, wxwindowdc.

a wxdc is a 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.

• wxscreendc. use this to paint on the screen, as opposed to an individual window.
• 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.
• wxpaintdc. use this to paint on the client area of a window, but only from within a wxpaintevent.
• 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:

  void mywindow::onmycmd(wxcommandevent& event)
  {
    wxclientdc dc(window);
    drawmypicture(dc);
  }