.. include:: headings.inc .. _device contexts: ==================================== |phoenix_title| **Device Contexts** ==================================== A :ref:`wx.DC` 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 :ref:`wx.ScreenDC`, :ref:`wx.ClientDC`, :ref:`wx.PaintDC`, and :ref:`wx.WindowDC`. The following describes the differences between these device contexts and when you should use them. - :ref:`wx.ScreenDC`. Use this to paint on the screen, as opposed to an individual window. - :ref:`wx.ClientDC`. 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 :ref:`wx.PaintEvent`. - :ref:`wx.PaintDC`. Use this to paint on the client area of a window, but only from within a :ref:`wx.PaintEvent`. - :ref:`wx.WindowDC`. 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:: def OnMyCmd(self, event): dc = wx.ClientDC(window) DrawMyPicture(dc) Try to write code so it is parameterised by :ref:`wx.DC` - 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.