A device context is a means of writing to a particular device. Before using GPI functions to cause output to be directed to the device context, the GpiAssociate function call must be issued (or the GPIA_ASSOC option specified on GpiCreatePS).
DevOpenDC cannot be used to open a device context for a screen window; use WinOpenWindowDC instead.
The device context is owned by the process from which DevOpenDC is issued. It cannot be accessed directly from any other process. If it still exists when the process terminates, it is automatically deleted by the system. When using a device context type of OD_METAFILE_NOQUERY the querying of attributes is not allowed. To improve performance of this type of metafile no error checking is performed to ensure that such API calls are not attempted. Query calls are accepted but the results returned are undefined.
This function requires the existence of a message queue.