Object cannot be cast from DBNull to other types

Question

i was trying to get the sum of the row items in a datagridview
this is my code

 Private Sub Button5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button5.Click


    If DataGridView1.RowCount > 1 Then
        Dim RegFee As Integer = 0
        Dim MisFee As Integer = 0
        Dim TuiFee As Integer = 0
        Dim PtcaFee As Integer = 0
        Dim CompFee As Integer = 0

        For index As Integer = 0 To DataGridView1.RowCount - 1
            RegFee += Convert.ToInt32(DataGridView1.Rows(index).Cells(4).Value)
            MisFee += Convert.ToInt32(DataGridView1.Rows(index).Cells(5).Value)
            TuiFee += Convert.ToInt32(DataGridView1.Rows(index).Cells(6).Value)
            PtcaFee += Convert.ToInt32(DataGridView1.Rows(index).Cells(7).Value)
            CompFee += Convert.ToInt32(DataGridView1.Rows(index).Cells(8).Value)

        Next
        DataGridView2.Rows.Add("Registration Fee", RegFee)
        DataGridView2.Rows.Add("Miscellaneous Fee", MisFee)
        DataGridView2.Rows.Add("Tuition Fee", TuiFee)
        DataGridView2.Rows.Add("PTCA Fee", PtcaFee)
        DataGridView2.Rows.Add("Computer Fee", CompFee)

    End If
End Sub

but i'm having an error:
Object cannot be cast from DBNull to other types.
can you help me???

if `Rows(index).Cells(N).Value` is nothing in the db, DBNull, it cant be added to anything like `RegFee`, `TuiFee` etc. you need to test for DBNull first — Ňɏssa Pøngjǣrdenlarp, Oct 14 '14 at 12:08
http://msdn.microsoft.com/en-us/library/tckcces5(v=vs.90).aspx you should also take the time to accept some of the many answers you get if/when they help — Ňɏssa Pøngjǣrdenlarp, Oct 14 '14 at 12:45

ilans · Accepted Answer · 2014-10-14T13:05:29.460

1

Use IsDbNull like this:

Private Sub Button5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button5.Click

If DataGridView1.RowCount > 1 Then
    Dim RegFee As Integer = 0
    Dim MisFee As Integer = 0
    Dim TuiFee As Integer = 0
    Dim PtcaFee As Integer = 0
    Dim CompFee As Integer = 0
    For index As Integer = 0 To DataGridView1.RowCount - 1
        RegFee += If(IsDbNull(DataGridView1.Rows(index).Cells(4).Value), 0,   Convert.ToInt32(DataGridView1.Rows(index).Cells(4).Value))
        'Do the same for the rest
    Next
    DataGridView2.Rows.Add("Registration Fee", RegFee)
    DataGridView2.Rows.Add("Miscellaneous Fee", MisFee)
    DataGridView2.Rows.Add("Tuition Fee", TuiFee)
    DataGridView2.Rows.Add("PTCA Fee", PtcaFee)
    DataGridView2.Rows.Add("Computer Fee", CompFee)
End If

End Sub

edited Oct 14 '14 at 13:05

answered Oct 14 '14 at 12:50

ilans

2,537
1
28
29

OK. Try again. Added the `.Value` – ilans Oct 14 '14 at 13:06
@Steve i'm still new in programming can you give me a sample code?i will really appreciate it :) – Kaye Santos Oct 14 '14 at 13:08
@KayeSantos - Try again. I've added the `.Value`. This should work: `RegFee += If(IsDbNull(DataGridView1.Rows(index).Cells(4).Value), 0, Convert.ToInt32(DataGridView1.Rows(index).Cells(4).Value))` – ilans Oct 14 '14 at 13:09

Object cannot be cast from DBNull to other types

1 Answers1

Linked