Question

I am trying to make an array of hashtables. I don’t know if this is the best solution, in PHP I would just do a multi-dim array, but it’s not so easy in .NET. I am pretty new o VB, so if there is a better solution for this please explain.

I have 2 emails fields for a contact, and a contact can have many. I just want to load in the first two on the edit page for editing, whatever they may be.

Private Sub loadPrimaryContactEmails(ByVal db As CRMDataDataContext, ByVal contactID As Guid)
        Dim q = (From ce In db.ContactEmails Where ce.ContactID = contactID Select ce).Take(2)
        Dim Emails As Array
        Dim count = 0
        For Each email In q
            Emails(count) = New Hashtable
            Emails(count).Add("email", email.Email)
            Emails(count).Add("label", email.Label)
            Emails(count).Add("id", email.ContactEmailID)
            count = count + 1
        Next
        txtPCEmail1.Text = Emails(0).Item("email")
        txtPCEmail1Label.Text = Emails(0).Item("label")
        lblEmail1ID.Text = Emails(0).Item("id")

        txtPCEmail2.Text = Emails(1).Item("email")
        txtPCEmail2Label.Text = Emails(1).Item("label")
        lblEmail2ID.Text = Emails(1).Item("id")
    End Sub

I get the error the first time I try to reference my array:

txtPCEmail1.Text = Emails(0).Item("email")

The error is:

Object variable or With block variable not set.

It builds, so I thought it might work. I can’t just loop through my datasource because I have to explicitly set textbox fields. Is there a better way to go about doing this? Or is there a way to make an array of hashtables work?

EDIT – here is the good code:
So I went w/ the HybridDictionary…

Private Sub loadPrimaryContactEmails(ByVal db As CRMDataDataContext, ByVal contactID As Guid)
        Dim q = (From ce In db.ContactEmails Where ce.ContactID = contactID Select ce).Take(2)
        Dim Emails As New HybridDictionary()
        Dim count = 1
        For Each email In q
            Emails.Add("email" + NCStr(count), email.Email)
            Emails.Add("label" + NCStr(count), email.Label)
            Emails.Add("id" + NCStr(count), email.ContactEmailID)
            count = count + 1
        Next
        txtPCEmail1.Text = Emails("email1")
        txtPCEmail1Label.Text = Emails("label1")
        lblEmail1ID.Text = Emails("id1")

        txtPCEmail2.Text = Emails("email2")
        txtPCEmail2Label.Text = Emails("label2")
        lblEmail2ID.Text = Emails("id2")
    End Sub

SO yeah, kind of a hack, but I don’t feel like I should have to making special methods just to load some data into a dictionary or array or whatever.

Answer 1

Yes Phil is right you haven’t specified the Initial Size of the Array.

And as suggested by him Use generic list or I would recommend

“System.Collections.Specialized.StringCollection” Class or “System.Collections.Specialized.HybridDictionary” class