سلام دوست عزيز
به اين كد توجه كن شايد مشكلت حل شود
PrivateSub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) HandlesMyBase.Load
DataGridView1.Columns("gheymat").ReadOnly = True
EndSub
PrivateSub DataGridView1_CellValidated(ByVal sender AsObject, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles DataGridView1.CellValidated
If DataGridView1.Item("tedad", e.RowIndex).Value IsNot DBNull.Value And DataGridView1.Item("fee", e.RowIndex).Value IsNot DBNull.Value Then
DataGridView1.Item("gheymat", e.RowIndex).Value = DataGridView1.Item("tedad", e.RowIndex).Value * DataGridView1.Item("fee", e.RowIndex).Value
EndIf
EndSub