UIGraphicsGetCurrentContext()
Returns the current graphics context.
Declaration
func UIGraphicsGetCurrentContext() -> CGContext?Return Value
The current graphics context.
Discussion
The current graphics context is nil by default. Prior to calling its drawRect: method, view objects push a valid context onto the stack, making it current. If you are not using a UIView object to do your drawing, however, you must push a valid context onto the stack manually using the UIGraphicsPushContext(_:) function.
This function may be called from any thread of your app.