Limit the size of List(Of T) - VB.NET

Question

I am trying to limit the size of my generic list so that after it contains a certain amount of values, it won\'t add any more.

I am trying to do this using the Capac

Answer 1

There are several different ways to add things to a List: Add, AddRange, Insert, etc.

Consider a solution that inherits from Collection:

Public Class LimitedCollection(Of T)
    Inherits System.Collections.ObjectModel.Collection(Of T)

    Private _Capacity As Integer
    Public Property Capacity() As Integer
        Get
            Return _Capacity
        End Get
        Set(ByVal value As Integer)
            _Capacity = value
        End Set
    End Property

    Protected Overrides Sub InsertItem(ByVal index As Integer, ByVal item As T)
        If Me.Count = Capacity Then
            Dim message As String = 
                String.Format("List cannot hold more than {0} items", Capacity)
            Throw New InvalidOperationException(message)
        End If
        MyBase.InsertItem(index, item)
    End Sub

End Class

This way the capacity is respected whether you Add or Insert.