I've looked into the DesignOnly attribute, but that doesn't seem to accomplish what I want*.

Basically, I'm looking for some way to indicate that some property of a user control (let's say Text) can be modified during design time -- i.e., from the Windows Forms designer in VS (or presumably from any GUI designer that can be used to modify a Windows Forms GUI) -- but not during run time. Once the application is running, the property should effectively be readonly.

Is this possible?

* _{When I add the DesignOnly attribute to a property, the value I select for that property from design mode doesn't seem to stick; the property just ends up being whatever I have it set to by default in code.}