Painting the borders of a custom control using WM_NCPAINT
Using the `WM_NCPAINT` and `WM_NCCALCSIZE` messages in order to create and paint a non-client region for a C# WinForms custom control

Using the `WM_NCPAINT` and `WM_NCCALCSIZE` messages in order to create and paint a non-client region for a C# WinForms custom control