IList-How can I use this interface

I dont Know how can I use Interface In General.
Please if someone can to send me some simple example
with e.g IList.Add or something else

You are not supposed to work with IList interface (uless you really have to).
Inherit from CollectionBase instead, or implement ICollection.

Interfaces in general define a contract that a class which inmplements that interface has to follow: The implementing class must implement all methods, properties and events that are in the interface.
Example:

Code:

---

Public Interface MyInterface
  Event E()
  Sub F(ByVal Value As Integer)
  Property P() As String
End Interface

Public Class MyClass
    Implements MyInterface
   
    (...) ' Must implement E,F,P
End Class

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The Interface

Code:

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public interface face
sub eye(..)
property weep(..) as integer
end interface

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2 class implementing the interface
Class1

Code:

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public class c1

implements face

sub eye(..) implements face.eye
....
end sub

public property weep() as integer implements face.weep
get
...
end get
set(byval a as integer)
...
end set
end property

end class

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Class2

Code:

---

public class c2
implements face

sub eye(..)as integer implements face.eye
....
end sub

public property weep() as integer implements face.weep
get
...
end get
set(byval a as integer)
...
end set
end property

end class

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testing the interface

Code:

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private sub form1_load(......

dim c1_1 as new c1
c1_1.weep=12
c1_1.eye(3)

dim c2_1 as new c2
c2_1.weep=4
c2_1.eye(2)

end sub

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