Changing from an Interface to an Abstract

[joshp1217]

Okay I have this Interface: interface myInterface { public void visible(bool view); } I was implementing the visible method in my other classes like this: visible(bool view) { if(view) { this.Left = -500000; blah blah blah } else { this.left = 0; blah blah blah } } Okay I need to change my interface to an abstract class, so i can just implement the visible method one time in the abstract, but i can't use "this.Left" in the abstract because it doesnt contain a method for "Left". It is probably a simple solution to this but how do I get this.Left, this.dock etc. to be available for use in my abstract class?

[Josh Smith]

Make an abstract property get-set called Left which the derived classes override. :josh: My WPF Blog[^]

[J4amieC]

further to Josh's suggestion, the point of an abstract class is to abstract the functionality (as the name implies). Something like this would satisfy public abstract class AbstractThing : myInterface { protected abstract void SetVisible(); protected abstract void SetInvisible(); public void Visible(bool view) { if(view) SetVisible(); else SetInvisible(); } } then your derived class, which has the Left property defined. public DerivedThing : AbstractThing { protected override void SetInvisible(){ this.Left = -50000; } protected override void SetVisible(){ this.Left = 0; } } or say you derive it and you wantr different behaviour for SetVisible and SetInvisible..eg/ public OtherDerivedThing : AbstractThing { protected override void SetInvisible(){ this.Visible= false; } protected override void SetVisible(){ this.Visible = true; } } --- How to get answers to your questions[^] -- modified at 10:36 Friday 14th July, 2006