A. I bound a radGrid control to a custom collection called FactoryList(of Tkey).
B. The FactoryList control derived from BindingList (of Tkey) and implements ITypedList as follow:
1. The GetItemProperties return a collection of ColumnPropertyDescriptor objects, each is derived from PropertyDescriptor class
2. The ColumnPropertyDescriptor class exposes information based on DataColumn meta-data i.e. ColumnName, ColumnType, and also handle SetValue and Get Value methods.
C. A FactoryList instance contains objects that are derived from a base class called BaseEntity. The BaseEntity class implements
ICustomTypeDescriptor, where the GetItemProperties retruns a collection of ColumnPropertyDescriptor same as the FactoryList class does.
D. I use the NeedDataSource event to bind the FactoryList to the radGrid
All works fine, till I sort the grid rows by clicking on one of the grid column headers. In that case I got the following error:
No property or field 'LST_NAME' exists in type 'Object'
- 'LST_NAME' is one the columns I was trying to sort
radGrid:
<
telerik:RadGrid ID="grdCustomLists" runat="server" AllowPaging="True"
AllowSorting="True" AutoGenerateColumns="False" AutoGenerateDeleteColumn="True"
AutoGenerateEditColumn="True" GridLines="None"
DataMember="esmBOA.SystemList">
<
MasterTableView CommandItemDisplay="Top" DataKeyNames="LST_ID" EditMode="InPlace"
DataMember="esmBOA.SystemList">
<CommandItemSettings AddNewRecordText="New List" />
<
RowIndicatorColumn>
<
HeaderStyle Width="20px"></HeaderStyle>
</
RowIndicatorColumn>
<
ExpandCollapseColumn>
<
HeaderStyle Width="20px"></HeaderStyle>
</
ExpandCollapseColumn>
<Columns>
<telerik:GridBoundColumn DataField="LST_ID" HeaderText="LST_ID" ReadOnly="True"
SortExpression="LST_ID" UniqueName="LST_ID" Visible="False"
Display="False">
</telerik:GridBoundColumn>
<telerik:GridBoundColumn DataField="LST_NAME" HeaderText="Name"
SortExpression="LST_NAME" UniqueName="LST_NAME">
</telerik:GridBoundColumn>
<telerik:GridBoundColumn DataField="LST_DSC" HeaderText="Description"
SortExpression="LST_DSC" UniqueName="LST_DSC">
</telerik:GridBoundColumn>
<telerik:GridCheckBoxColumn DataField="LST_IS_SYSTEM" DataType="System.Boolean"
HeaderText="LST_IS_SYSTEM" SortExpression="LST_IS_SYSTEM"
UniqueName="LST_IS_SYSTEM" Visible="False" Display="False" ReadOnly="True">
</telerik:GridCheckBoxColumn>
<telerik:GridCheckBoxColumn DataField="LST_CAN_EDIT" DataType="System.Boolean"
HeaderText="LST_CAN_EDIT" SortExpression="LST_CAN_EDIT"
UniqueName="LST_CAN_EDIT" Visible="False" Display="False" ReadOnly="True">
</telerik:GridCheckBoxColumn>
<telerik:GridCheckBoxColumn DataField="LST_CAN_DELETE"
DataType="System.Boolean" HeaderText="LST_CAN_DELETE"
SortExpression="LST_CAN_DELETE" UniqueName="LST_CAN_DELETE"
Visible="False" Display="False" ReadOnly="True">
</telerik:GridCheckBoxColumn>
<telerik:GridCheckBoxColumn DataField="LST_IS_DELETED"
DataType="System.Boolean" HeaderText="LST_IS_DELETED"
SortExpression="LST_IS_DELETED" UniqueName="LST_IS_DELETED"
Visible="False" Display="False" ReadOnly="True">
</telerik:GridCheckBoxColumn>
</Columns>
</
MasterTableView>
<ClientSettings>
<Selecting AllowRowSelect="True" />
</ClientSettings>
</telerik:RadGrid>
ColumnPropertyDescriptor Class (VB) - SystemField class stores the DataColumn meta-data
Public
Class ColumnPropertyDescriptor
Inherits System.ComponentModel.PropertyDescriptor
#Region
"Attributes"
Private _column As SystemField
#End
Region
#Region
"Constractor"
Public Sub New(ByVal column As SystemField)
MyBase.New(column.ColumnName, Nothing)
_column = column
End Sub
#End
Region
#Region
"Properties"
Public Property Column() As SystemField
Get
Return _column
End Get
Set(ByVal value As SystemField)
_column = value
End Set
End Property
#End
Region
#Region
"PropertyDescriptor Overrides"
#Region
"Properties"
Public Overrides ReadOnly Property Converter() As System.ComponentModel.TypeConverter
Get
Return ComponentModel.TypeDescriptor.GetConverter(Me.PropertyType)
End Get
End Property
Public Overrides ReadOnly Property DisplayName() As String
Get
Return _column.Properties.Caption
End Get
End Property
Public Overrides ReadOnly Property Name() As String
Get
Return _column.ColumnName
End Get
End Property
Public Overrides ReadOnly Property ComponentType() As System.Type
Get
Return Me.PropertyType
End Get
End Property
Public Overrides ReadOnly Property IsReadOnly() As Boolean
Get
Return _column.Properties.IsEdit
End Get
End Property
Public Overrides ReadOnly Property PropertyType() As System.Type
Get
Return _column.SystemColumnType
End Get
End Property
#End
Region
#Region
"Public Methods"
Public Overrides Function CanResetValue(ByVal component As Object) As Boolean
Return False
End Function
Public Overrides Function GetValue(ByVal component As Object) As Object
Dim item As BaseEntity = CType(component, BaseEntity)
Return item.Field(Me._column.ColumnName)
End Function
Public Overrides Sub ResetValue(ByVal component As Object)
Throw New NotImplementedException
End Sub
Public Overrides Sub SetValue(ByVal component As Object, ByVal value As Object)
Dim item As BaseEntity = CType(component, BaseEntity)
item.Field(
Me._column.ColumnName) = value ' value is stored in a key dictionary
End Sub
Public Overrides Function ShouldSerializeValue(ByVal component As Object) As Boolean
Return False
End Function
#End
Region
#End
Region
End
Class
BaseEntity Class:
Imports
System.ComponentModel
Public
Class BaseEntity
Implements ICustomTypeDescriptor
#Region
"Data Members"
Private _dataItem As Connectivity.DataItem
Private _values As New Dictionary(Of String, Object)
Private _originalID As String
Private _originalVTS As Date
Private _isNew As Boolean = False
Private _isModified As Boolean = False
Private _PropertyCollection As PropertyDescriptorCollection = New PropertyDescriptorCollection(Nothing)
#End
Region
#Region
"Constractor"
Public Sub New(ByRef DataItem As esmOPM.Connectivity.DataItem, ByVal fetchLevel As esmOPM.FetchLevel, ByVal entityDataRow As DataRow)
_dataItem = DataItem
If IsNothing(entityDataRow) Then
_isNew =
True
' create empty dictionary
For Each sf In _dataItem.Fields(fetchLevel)
_values.Add(sf.ColumnName,
Nothing)
_PropertyCollection.Add(
New ColumnPropertyDescriptor(sf))
Next sf
Else
_isNew =
False
' parse row-dara values
For Each sf In _dataItem.Fields(fetchLevel)
_values(sf.ColumnName) = entityDataRow(sf.ColumnName)
_PropertyCollection.Add(
New ColumnPropertyDescriptor(sf))
Next
_originalID = entityDataRow(_dataItem.PKFieldName).ToString
_originalVTS = entityDataRow(_dataItem.VTSFieldName)
End If
End Sub
#End
Region
#Region
"Public Data Properties"
Public Property Field(ByVal columnName As Object) As Object
Get
Return _values(columnName)
End Get
Set(ByVal value As Object)
_setFieldValue(columnName, value)
End Set
End Property
Public ReadOnly Property ID() As String
Get
Return _values(_dataItem.PKFieldName).ToString
End Get
End Property
Public Property IsNew() As Boolean
Get
Return _isNew
End Get
Set(ByVal value As Boolean)
_isNew = value
End Set
End Property
Public Property IsModified() As Boolean
Get
Return _isModified
End Get
Set(ByVal value As Boolean)
_isModified = value
End Set
End Property
#End
Region
#Region
"Internal Properties"
Friend ReadOnly Property Original_ID() As String
Get
Return _originalID
End Get
End Property
Friend ReadOnly Property Original_VTS() As Date
Get
Return _originalVTS
End Get
End Property
#End
Region
#Region
"Public Methods"
Public Sub ParseValues(ByVal valuesDisctionary As Dictionary(Of String, Object))
For Each de In valuesDisctionary
Me.Field(de.Key) = de.Value
Next de
End Sub
#End
Region
#Region
"Private Methods"
Private Sub _setFieldValue(ByVal columnName As String, ByVal value As Object)
' store old values
If Not (_isNew) AndAlso columnName = _dataItem.PKFieldName Then
_originalID =
Me.Field(columnName).ToString
End If
If Not (_isNew) AndAlso columnName = _dataItem.VTSFieldName Then
_originalVTS =
CDate(Me.Field(columnName))
End If
' set current value
_values(columnName) = value
' mark this object as being modified
_isModified =
True
' set new timestamp value
_values(_dataItem.VTSFieldName) = Now()
End Sub
#End
Region
Public Function GetAttributes() As System.ComponentModel.AttributeCollection Implements System.ComponentModel.ICustomTypeDescriptor.GetAttributes
Return New System.ComponentModel.AttributeCollection(Nothing)
End Function
Public Function GetClassName() As String Implements System.ComponentModel.ICustomTypeDescriptor.GetClassName
Return Nothing
End Function
Public Function GetComponentName() As String Implements System.ComponentModel.ICustomTypeDescriptor.GetComponentName
Return Nothing
End Function
Public Function GetConverter() As System.ComponentModel.TypeConverter Implements System.ComponentModel.ICustomTypeDescriptor.GetConverter
Return Nothing
End Function
Public Function GetDefaultEvent() As System.ComponentModel.EventDescriptor Implements System.ComponentModel.ICustomTypeDescriptor.GetDefaultEvent
Return Nothing
End Function
Public Function GetDefaultProperty() As System.ComponentModel.PropertyDescriptor Implements System.ComponentModel.ICustomTypeDescriptor.GetDefaultProperty
Return Nothing
End Function
Public Function GetEditor(ByVal editorBaseType As System.Type) As Object Implements System.ComponentModel.ICustomTypeDescriptor.GetEditor
Return Nothing
End Function
Public Function GetEvents() As System.ComponentModel.EventDescriptorCollection Implements System.ComponentModel.ICustomTypeDescriptor.GetEvents
Return New EventDescriptorCollection(Nothing)
End Function
Public Function GetEvents(ByVal attributes() As System.Attribute) As System.ComponentModel.EventDescriptorCollection Implements System.ComponentModel.ICustomTypeDescriptor.GetEvents
Return New EventDescriptorCollection(Nothing)
End Function
Public Function GetProperties() As System.ComponentModel.PropertyDescriptorCollection Implements System.ComponentModel.ICustomTypeDescriptor.GetProperties
Return _PropertyCollection
End Function
Public Function GetProperties(ByVal attributes() As System.Attribute) As System.ComponentModel.PropertyDescriptorCollection Implements System.ComponentModel.ICustomTypeDescriptor.GetProperties
Return _PropertyCollection
End Function
Public Function GetPropertyOwner(ByVal pd As System.ComponentModel.PropertyDescriptor) As Object Implements System.ComponentModel.ICustomTypeDescriptor.GetPropertyOwner
Return Me
End Function
End
Class
and finally ... FactoryList Class:
Imports
System.ComponentModel
Imports
esmOPM.Connectivity
Public
Class esmList(Of Tkey)
Inherits BindingList(Of Tkey)
Implements ITypedList
#Region
"Data Members"
Private _PropertyCollection As PropertyDescriptorCollection = New PropertyDescriptorCollection(Nothing)
#End
Region
#Region
"Properties"
Friend WriteOnly Property Fields() As List(Of SystemField)
Set(ByVal value As List(Of SystemField))
End Set
End Property
#End
Region
#Region
"Constractors"
Public Sub New(ByVal fields As List(Of SystemField))
MyBase.New()
' init propertyCollection
_PropertyCollection.Clear()
For Each sf In fields
_PropertyCollection.Add(
New ColumnPropertyDescriptor(sf))
Next sf
End Sub
#End
Region
Public Function GetItemProperties(ByVal listAccessors() As System.ComponentModel.PropertyDescriptor) As System.ComponentModel.PropertyDescriptorCollection Implements System.ComponentModel.ITypedList.GetItemProperties
Return _PropertyCollection
End Function
Public Function GetListName(ByVal listAccessors() As System.ComponentModel.PropertyDescriptor) As String Implements System.ComponentModel.ITypedList.GetListName
Return "DefaultView"
End Function
End
Class
1 Answer, 1 is accepted
Please take a look at the Various DataSources demo of the RadGrid showing how to bind the grid to custom collections with sorting enabled. Another option is to implement custom sorting.
If the described issue persists, please open a formal support ticket and attach a sample project replicating the error. We will debug it locally and get back to you with our findings.
Sincerely yours,
Mira
the Telerik team
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