Gets the list of RasterPaintCallbacks objects containing the custom callbacks.
You add or remove custom callbacks using the members of the .NET IList, ICollection and IEnumerable interfaces.
If your callbacks are using unmanaged memory, it is recommended you clear the PaintCallbacks list and dispose of your class when you no longer use the RasterPaintProperties object.
The PaintCallbacks list is always valid, even if the list is empty. So you do not need to check whether it is null.
For a C++ example, refer to RasterPaintCallbacks.