How to set a value into the cell in WinForms GridControl?

int rowIndex = 1, columnIndex = 2;
gridControl1[rowIndex, columnIndex].CellValue = "PI";
rowIndex++;
gridControl1[rowIndex, columnIndex].CellValue = 3.14159;
rowIndex++;
gridControl1[rowIndex, columnIndex].CellValue = DateTime.Now;

Dim rowIndex As Integer = 1, columnIndex As Integer = 2
gridControl1(rowIndex, columnIndex).CellValue = "PI"
rowIndex += 1
gridControl1(rowIndex, columnIndex).CellValue = 3.14159
rowIndex += 1
gridControl1(rowIndex, columnIndex).CellValue = DateTime.Now

//Hook the QueryCellInfo event in Form_Load 
gridControl1.QueryCellInfo += gridControl1_QueryCellInfo;
void gridControl1_QueryCellInfo(object sender,GridQueryCellInfoEventArgs e)
{
    if (e.ColIndex == 3)
    {
        if (e.RowIndex == 1)
            e.Style.CellValue = "Fraction";
        if(e.RowIndex == 2)
            e.Style.CellValue = "22/7";
        if(e.RowIndex == 3)
            e.Style.CellValue = DateTime.Now;
    }
}

'Hook the QueryCellInfo event in Form_Load 
Private gridControl1.QueryCellInfo += AddressOf gridControl1_QueryCellInfo
Private Sub gridControl1_QueryCellInfo(ByVal sender As Object, ByVal e As GridQueryCellInfoEventArgs)
    If e.ColIndex = 3 Then
          If e.RowIndex = 1 Then
                e.Style.CellValue = "Fraction"
          End If
          If e.RowIndex = 2 Then
                e.Style.CellValue = "22/7"
          End If
          If e.RowIndex = 3 Then
                e.Style.CellValue = DateTime.Now
          End If
    End If
End Sub