Extending GridView: new Behavior DefaultValue not working...

Question

User-44394457 posted

Using VS2005, VB code behind,

I an expanding on the HotGridView control (http://msdn.microsoft.com/en-us/magazine/cc163612.aspx). During testing I noticed the "AutoGenerateCheckBoxColumn" behavior was returning true even if the user did not specify the a value in the markup but I expect it to return False if not value is supplied by the user - can anyone shed some light on why the AutoGenerateCheckBoxColumn is always true if not explicitly set to False in the markup? 

        <Category("Behavior")> _
        <Description("Whether a checkbox column is generated automatically at runtime")> _
        <DefaultValue(False)> _
        Public Property AutoGenerateCheckBoxColumn() As Boolean
            Get
                Dim _obj As Object = ViewState("AutoGenerateCheckBoxColumn")
                If _obj Is Nothing Then
                    Return False
                Else
                    Return DirectCast(_obj, Boolean)
                End If
            End Get
            Set(ByVal value As Boolean)
                ViewState("AutoGenerateCheckBoxColumn") = value
            End Set
        End Property

        ''' <summary>
        ''' CreateColumns
        ''' </summary>
        ''' <param name="dataSource"></param>
        ''' <param name="useDataSource"></param>
        ''' <returns></returns>
        ''' <remarks></remarks>
        Protected Overrides Function CreateColumns(ByVal dataSource As PagedDataSource, ByVal useDataSource As Boolean) As ICollection
            ' Let the GridView create the default set of columns
            Dim _columnList As ICollection = MyBase.CreateColumns(dataSource, useDataSource)
            If Me.AutoGenerateCheckBoxColumn Then
                ' Add a checkbox column if required
                Dim _extendedColumnList As ArrayList = Me.AddCheckBoxColumn(_columnList)
                Return _extendedColumnList
            Else
                Return _columnList
            End If

        End Function