index is outside the bounds of the array vb.net - asp.net

Question

Private Sub GetGeneralMemberInformation(Member As WebServices.MemberInfoService.Member)
Try
Dim error_msg As String = "The following Member is not Eligible to display the data: {0} "
SubscriberId = Member.SubscriberId
If Member.Eligibility(0) Is Nothing Then
Throw New Exception(String.Format(error_msg, SubscriberId))
End If
Catch ex As Exception
Throw ex
End Try
End Sub
I'm unable to check do null check on the Eligibility object .while checking itself i'm getting the error like index is outside the bounds of the array . Can any body suggest me how to do null check and i want display mu custom error message instead of that one and here eligibility object don't have any data.

Answer 1

As others have noted, Eligibility may be empty. Since you clarified that Eligibility is a List(Of Object), I updated the code sample below to reflect that.
Imports System
Imports System.Collections.Generic
Public Module Module1
Public Sub Main()
Dim member1 = New Member()
member1.Eligibilities = New List(Of MemberEligibility)
' REMARKS: List is empty
If member1.Eligibilities.Count > 0 Then
If member1.Eligibilities(0) Is Nothing Then
Console.WriteLine("First element is NULL")
End If
End If
' REMARKS: Add one element to list
member1.Eligibilities.Add(New MemberEligibility())
' REMARKS: List contains one element
If member1.Eligibilities.Count > 0 Then
If member1.Eligibilities(0) IsNot Nothing Then
Console.WriteLine("First element is initialized")
End If
End If
End Sub
End Module
Public Class Member
Private _eligibility As MemberEligibility
Private _eligibilities As List(Of MemberEligibility)
Public Sub New()
End Sub
Public Property Eligibility As MemberEligibility
Get
Return Me._eligibility
End Get
Set
Me._eligibility = Value
End Set
End Property
Public Property Eligibilities As List(Of MemberEligibility)
Get
Return Me._eligibilities
End Get
Set
Me._eligibilities = Value
End Set
End Property
End Class
Public Class MemberEligibility
Public Sub New()
End Sub
End Class
Here is a .NET Fiddle showing the above code in action.