It depends on what kind of functionality you want. If you only need the properties to be set when you add the control to a form, then setting the properties in the control's constructor works perfectly. However, changes you make using the Properties panel will take precedence, and setting properties in the control's constructor won't necessarily affect existing instances of the control.
If you want to be able to change the properties for instances of the control in one place, assigning bindings in (application settings), (property bindings) works. Then you can modify all the bindings from the Settings.settings file. This still requires you to assign property bindings for each instance of the control, though.
Now for the finale. If you want to set properties in the control's class that affect all instances of the control, whether the instances are yet to be created or already exist, you have to get a little creative. I found a solution, but it may not be the best. My solution goes like this:
In the control's constructor, for each property you want to set, you:
- Store the desired value in a private variable.
- Assign the variable's value to the property.
- Assign an event handler that assigns the variable's value to the property whenever the property is changed.
A downside is the amount of coding for each property. Also, you wouldn't be able to change the properties from the Properties pane.