RenderSurface

Rules worth knowing

These are the operational rules that matter when you use RenderSurface in a real app.

Manual and managed modes are not blended. If managed mode is active, the managed presentation surface wins while it is active.
If managed mode later becomes inactive, the previously assigned manual surface becomes visible again.
Managed resources are recreated when the arranged size changes or the graphics device changes.
InvalidateVisual() in managed mode marks the managed surface dirty so it will be redrawn.
RefreshSurface() is the lightweight "redraw this surface" signal when the underlying content changed.
ClearSurface() clears the manually assigned surface reference.
OnFrameUpdate only matters in managed mode, and only when IsFrameUpdateActive returns true.

Recommended rule of thumb: if your gameplay code already produces a texture, use manual mode. If you want ad hoc drawing from a screen or view, use the DrawSurface event. If the thing you are building deserves to become a reusable control, subclass RenderSurface and own the drawing behavior there.