Customizing BoundField

This is a way to customize BoundField, to be able to support multiline textbox.

Namespace System.Web.UI.WebControls
    Public Class MultilineField
        Inherits BoundField

        Private m_Rows As Integer

        Public Property Rows() As Integer
            Get
                Return m_Rows
            End Get
            Set(ByVal value As Integer)
                m_Rows = value
                Me.OnFieldChanged()
            End Set
        End Property

        Protected Overrides Function CreateField() As DataControlField
            Return New MultilineField
        End Function

        Protected Overrides Sub InitializeDataCell(ByVal cell As DataControlFieldCell, ByVal rowState As DataControlRowState)
            MyBase.InitializeDataCell(cell, rowState)
            If (rowState And DataControlRowState.Insert) Or (rowState And DataControlRowState.Edit) And (Me.DataField <> "") Then
                With CType(cell.Controls(0), TextBox)
                    .TextMode = TextBoxMode.MultiLine
                    .Rows = Me.Rows
                End With
            End If
        End Sub
    End Class
End Namespace