I created a custom control which is a simple subclass of the DataGrid.  I
wanted to display a message when the DataSource is empty.  Right now I am
assuming the datasource is a datareader.

The problem is in design mode.  I get the error "Error in displaying...".
This is caused by the DataSource override property trying to access the data
source at design time.  How do I set things up to avoid this design time
problem.

Thanks.  Jay

Imports System.ComponentModel

Imports System.Web.UI

Public Class MyDataGrid

Inherits System.Web.UI.WebControls.DataGrid

Public ShowMyHeader As Boolean = True

Public NoDataMessage As String = "No Data Is Available!"

Private HasData As Boolean

'Public Overrides Property DataSource() As Object

' Get

' Return (MyBase.DataSource)

' End Get

' Set(ByVal aDataSource As Object)

' HasData = aDataSource.HasRows

' MyBase.DataSource = aDataSource

' End Set

'End Property

Protected Overrides Sub Render(ByVal writer As System.Web.UI.HtmlTextWriter)

If HasData Then

MyBase.Render(writer)

Else

Dim Message As New System.Web.UI.WebControls.Label

Message.Text = NoDataMessage

Message.Font.Bold = True

Message.Font.Size = System.Web.UI.WebControls.FontUnit.Point(10)

Message.Font.Name = "arial"

Message.ForeColor = System.Drawing.Color.Red

Me.ShowHeader = Me.ShowMyHeader

writer.AddAttribute(HtmlTextWriterAttribute.Border, "0")

writer.AddAttribute(HtmlTextWriterAttribute.Cellpadding, "0")

writer.AddAttribute(HtmlTextWriterAttribute.Cellspacing, "0")

writer.RenderBeginTag(HtmlTextWriterTag.Table)

writer.RenderBeginTag(HtmlTextWriterTag.Tr)

writer.AddAttribute(HtmlTextWriterAttribute.Align, "center")

writer.RenderBeginTag(HtmlTextWriterTag.Td)

MyBase.Render(writer)

writer.RenderEndTag() ' Td

writer.RenderEndTag() ' Tr

writer.RenderBeginTag(HtmlTextWriterTag.Tr)

writer.AddAttribute(HtmlTextWriterAttribute.Align, "center")

writer.AddAttribute(HtmlTextWriterAttribute.Valign, "bottom")

writer.AddAttribute(HtmlTextWriterAttribute.Height, "30")

writer.RenderBeginTag(HtmlTextWriterTag.Td)

Message.RenderControl(writer)

writer.RenderEndTag() ' Td

writer.RenderEndTag() ' Tr

writer.RenderEndTag() ' Table

End If

End Sub

End Class