Why is RenderControl called when a Control's Visible property is set to false?

Question

I've put a breakpoint on my Control's overridden RenderControl method and the breakpoint is being hit, but in Visual Studio, I can see that this.Visible is false .

In the documentation for the Visible property it says:

If this property is false, the server control is not rendered.

This doesn't necessarily mean the RenderControl method is not called, but it's a big hint that it shouldn't do. Should I be jumping out of the method manually if Visible is false? Is this documented anywhere?

Answer 1

Accorging to msdn :

Before rendering, view state is saved for the page and all controls. During the rendering stage, the page calls the Render method for each control , providing a text writer that writes its output to the OutputStream object of the page's Response property.

And as you can see from the diagramm below, RenderControl is a part of Render process:

So it call the method RenderControl regardless Visible prop value. It's your responsibility to output empty string or anything based on Visible property.