Visual Basic

first = IIf(IsDBNull(_row.Cells(1)), 0, CDec(_row.Cells(1).Value))
second = IIf(IsDBNull(_row.Cells(2)), 0, CDec(_row.Cells(2).Value))
final = IIf(IsDBNull(_row.Cells(3)), 0, CDec(_row.Cells(3).Value))

For Each _row As DataGridViewRow In dgvGrades.Rows
                Dim first, second, final As Decimal

                ' ********* This doesnt not seem to work but technically it should **************
                ' ********* Must be a FLAW in VB.net :-) lol ************
                'first = IIf(TypeOf _row.Cells(1).Value Is DBNull, 0, CDec(_row.Cells(1).Value))
                'second = IIf(TypeOf _row.Cells(2).Value Is DBNull, 0, CDec(_row.Cells(2).Value))
                'final = IIf(TypeOf _row.Cells(3).Value Is DBNull, 0, CDec(_row.Cells(3).Value))

                first = IIf(IsDBNull(_row.Cells(1).Value), 0, CDec(_row.Cells(1).Value))
                second = IIf(IsDBNull(_row.Cells(2).Value), 0, CDec(_row.Cells(2).Value))
                final = IIf(IsDBNull(_row.Cells(2).Value), 0, CDec(_row.Cells(3).Value))

                Dim _average As Decimal = (first + second + 2 * final) / 4

                For Each _sRow As DataGridViewRow In dgvStudents.Rows
                    If _row.Cells(0).Value Is Nothing Then
                        Exit For
                    Else
                        If _row.Cells(0).Value = _sRow.Cells(0).Value Then
                            dgvAverage.Rows.Add(New Object() {_sRow.Cells(2).Value.ToString() + " " + _sRow.Cells(1).Value.ToString(), _average.ToString(), CalculateGrade(_average), IIf(_average > 59, True, False)})
                            Exit For
                        End If
                    End If
                Next
            Next

If IsDBNull(_row.Cells(1).Value) Then
MessageBox.Show("IT IS NULL!")
End If

final = IIf(IsDBNull(_row.Cells(2).Value), 0, CDec(_row.Cells(3).Value))

't = true part of iif / e = else part of iif
public function MyIIF (b as boolean, t as object, e as object) as object

public function MyIIF (b as boolean, t as string, e as string) as object
public function MyIIF (b as boolean, t as integer, e as integer) as object

Dim s$ = my...readalllines(myfile.txt)

Prankur Rusia wrote:

So what do you suggest now?

Private sub GetData()

  dim Query1 as string="Select * from My_Table"
  Dim Da1 as SqlDataadapter,Ds1 as new Dataset,dtb1 as new datatable
  con.open()
  Da1=new sqlDataAdapter(Query1,con)
  Da1.Fill(Ds1)
  con.close()
  dtb1=Ds1.Tables(0)

  ' Update your UI here...

End Sub

Private Sub FormLoad(...)...
  GetData() 
End Sub

Private Sub ComboBox_Click(...)...
  ComboBox.Items.Clear()
  GetData()
End Sub