specified cast is not valid, again!

[Patrick Sullivan]

Hi,

I get a "specified cast is not valid" when the
"cboContactName_SelectedIndexChanged" tries to put a new value into the
txtCompany textbox. I am using relations in this and have not used them much
before. I was getting an error before this one that complained about no
primary key, so I put that in. The error is in the last section. The rest is
so you can see the setup. TIA!

Private Sub ContactForm_Load(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Load

LoadData()

doDatabinding()

End Sub

Sub LoadData()

Dim conn As New SqlConnection(CONNECTION_STRING)

Dim da1 As New SqlDataAdapter("SELECT compID, compName FROM Companies ORDER
BY compName", conn)

Dim da2 As New SqlDataAdapter("SELECT * FROM Contacts ORDER BY contactName",
conn)

da1.TableMappings.Add("Table", "Companies")

da2.TableMappings.Add("Table", "Contacts")

ds.Clear()

da1.Fill(ds)

da2.Fill(ds)

Dim pColumn As DataColumn = ds.Tables("Companies").Columns("compID")

Dim cColumn As DataColumn = ds.Tables("Contacts").Columns("contactCompany")

ds.Relations.Add("FK_Contacts", pColumn, cColumn)

ds.Tables("Companies").PrimaryKey = New DataColumn()
{ds.Tables("Companies").Columns("compID")}

End Sub

Private Sub doDataBinding()

With cboCompanies

..DataSource = ds.Tables("Companies")

..ValueMember = "compID"

..DisplayMember = "compName"

..DropDownStyle = ComboBoxStyle.DropDownList

End With

With cboContactName

..DataSource = ds.Tables("Contacts")

..DisplayMember = "contactName"

..DropDownStyle = ComboBoxStyle.DropDown

End With

txtPhone.DataBindings.Add("Text", ds.Tables("Contacts"), "contactPhone")

txtEmail.DataBindings.Add("Text", ds.Tables("Contacts"), "contactEmail")

txtLMeeting.DataBindings.Add("Text", ds.Tables("Contacts"),
"contactLastMeeting")

txtCompany.DataBindings.Add("Text", ds.Tables("Companies"), "compName")

DisableControls(True)

DisableEdits(True)

End Sub

Private Sub cboContactName_SelectedIndexChanged(ByVal sender As
System.Object, ByVal e As System.EventArgs) Handles
cboContactName.SelectedIndexChanged

Dim SelectedContactID As Int32

SelectedContactID = cboContactName.SelectedValue

Dim SelectedContact As DataRow

SelectedContact = ds.Tables("Companies").Rows.Find(SelectedContactID)

*** error happens here *** txtCompany = SelectedContact.Item("compName")

End Sub

 

[Greg Burns]

txtCompany = SelectedContact.Item("compName")

shouldn't that be more like:

txtCompany.Text = SelectedContact.Item("compName")

I would turn on Option Strict to do more troubleshooting.

Greg

 

[Patrick Sullivan]

Thanks Greg, you're probably right. That's what comes when adding features
to stuff that already worked. THANK YOU!