Property

[MaiK]

Hi,

 

Im working with PropertyGrid, and one of my properties is Enum. I want use the description of enum value as DisplayMember and value as ValueMember

It worked me on winform combobox, but I try it in EditorRequired event, and nothing happends.

editor = New PropertyGridDropDownListEditor
element = CType(editor.EditorElement, BaseDropDownListEditorElement)

element.ValueMember = "Value"
element.DisplayMember = "Description"
element.DataSource = Tools.GetEnumValueDescription(Of MyEnum)()

e.Editor = editor

When I click in that enum property, values I can select are the same as I dont use that code.

 

What I am doing wrong?

 

Thank you!

 

[Hristo]

Hello Mikel,

Thank you for writing.

I can suggest handling the EditorInitialized event of the control for the enum item. Then in the event handler, you can subscribe the editor element to the VisualItemFormatting event and change the text of the items displayed in the popup. Please check the following documentation for additional information: https://docs.telerik.com/devtools/winforms/propertygrid/editors/handling-editors'-events.

I hope this helps. Let me know if you have other questions.

Regards,
Hristo
Progress Telerik

[MaiK]

Hello Hristo,

 

I have been trying with VisualItemFormmating but I dont know how to do. I explain my case.

That is my enum

Public Enum TestEnum
        <Description("A")> a
        <Description("B")> b
        <Description("C")> c
        <Description("D")> d
End Enum

I have this class for wrap enum value and description

Public Class EnumValueDescription

#Region "Propiedades"

#Region "Value"

    Private _Value As [Enum]

    Public Property Value() As [Enum]
        Get
            Return _Value
        End Get
        Set(ByVal value As [Enum])
            _Value = value
        End Set
    End Property

#End Region

#Region "Description"

    Private _Description As String

    Public Property Description() As String
        Get
            Return _Description
        End Get
        Set(ByVal value As String)
            _Description = value
        End Set
    End Property

#End Region

#End Region

End Class

This code converts enum to that list of objects:

Public Function GetEnumValueDescription(Of T)() As List(Of EnumValueDescription)
        Try
            'Checekea si el enum es correcto
            If (Not GetType(T).IsEnum) Then
                Throw New ArgumentException("T debe ser un enumerador")
            End If

            'Obtiene los valores y descripciones del enum
            Return [Enum].GetValues(GetType(T)).Cast(Of [Enum])().Select(Function(value) New EnumValueDescription With {.Value = value,
                                                                                                                  .Description = CType(Attribute.GetCustomAttribute(value.GetType().GetField(value.ToString()), GetType(DescriptionAttribute)), DescriptionAttribute).Description}).ToList()

        Catch ex As Exception
            Throw New Exception(String.Format("Error obteniendo los valores del enum '{0}'.{1}{2}", GetType(T).Name, vbNewLine, ex.Message), ex)
        End Try

    End Function

 

Doing it in winform combobox I just do that:

combobox.ValueMember = "Value"
combobox.DisplayMember = "Description"
combobox.DataSource = Tools.GetEnumValueDescription(Of TestEnum)()

 

Using EditorRequired event, with properties that are not enums my aproach works good with seting list(of myobj) and setting valuemember and displaymember, but doesnt work with enum properties. I try with EditorInitialized and doesnt works :/.

Can you give me and example of code please?

 

Thank you very much!

 

 

 

[Hristo]

Hello Mikel,

In the VisualItemFormatting event of the editor element, you have access to the items displayed in the list and you can alter their text. The code snippet you have provided demonstrates better your local setup and actually a similar to your initial approach could work. Instead of handling the EditorRequired event you will need to handle the EditorInitialized event where you can change the data source of the existing editor. It will be also necessary to sync the currently selected index. I am assuming that you will also need to change the text of the value element so you will also need to handle the ItemFormatting event of the property grid. Please check my code snippet below: 

Public Class RadForm1
    Sub New()

        InitializeComponent()

        Me.ComboBox1.ValueMember = "Value"
        Me.ComboBox1.DisplayMember = "Description"
        Me.ComboBox1.DataSource = Me.GetEnumValueDescription(Of TestEnum)()

        Me.RadDropDownList1.ValueMember = "Value"
        Me.RadDropDownList1.DisplayMember = "Description"
        Me.RadDropDownList1.DataSource = Me.GetEnumValueDescription(Of TestEnum)()

        Me.RadPropertyGrid1.SelectedObject = New PropertyGridDataModel With {
            .Id = 1,
            .Name = "John Doe",
            .TestEnum = TestEnum.A
        }

        AddHandler Me.RadPropertyGrid1.EditorInitialized, AddressOf RadPropertyGrid1_EditorInitialized
        AddHandler Me.RadPropertyGrid1.ItemFormatting, AddressOf RadPropertyGrid1_ItemFormatting

    End Sub

    Private Sub RadPropertyGrid1_ItemFormatting(sender As Object, e As PropertyGridItemFormattingEventArgs)
        If TypeOf (TryCast(e.Item, PropertyGridItem)).Value Is TestEnum Then
            Dim value = DirectCast(TryCast(e.Item, PropertyGridItem).Value, TestEnum)
            DirectCast(e.VisualElement, PropertyGridItemElement).ValueElement.Text = Me.GetSingleEnumValueDescription(value)
        Else
            e.VisualElement.ResetValue(LightVisualElement.TextProperty, Telerik.WinControls.ValueResetFlags.Local)
        End If

    End Sub

    Private Sub RadPropertyGrid1_EditorInitialized(sender As Object, e As PropertyGridItemEditorInitializedEventArgs)
        If TypeOf (TryCast(e.Item, PropertyGridItem)).Value Is TestEnum Then
            Dim editor = CType(e.Editor, PropertyGridDropDownListEditor)
            Dim element = CType(editor.EditorElement, BaseDropDownListEditorElement)
            Dim index = element.SelectedIndex

            element.DataSource = Nothing
            element.ValueMember = "Value"
            element.DisplayMember = "Description"
            element.DataSource = Me.GetEnumValueDescription(Of TestEnum)()
            element.SelectedIndex = index
        End If
    End Sub

    Public Function GetEnumValueDescription(Of T)() As List(Of EnumValueDescription)
        Try
            'Checekea si el enum es correcto
            If (Not GetType(T).IsEnum) Then
                Throw New ArgumentException("T debe ser un enumerador")
            End If

            'Obtiene los valores y descripciones del enum
            Return [Enum].GetValues(GetType(T)).Cast(Of [Enum])().Select(Function(value) New EnumValueDescription With {.Value = value,
                                                                                                                  .Description = CType(Attribute.GetCustomAttribute(value.GetType().GetField(value.ToString()),
                                                                                                                                                                    GetType(DescriptionAttribute)), DescriptionAttribute).Description}).ToList()

        Catch ex As Exception
            Throw New Exception(String.Format("Error obteniendo los valores del enum '{0}'.{1}{2}", GetType(T).Name, vbNewLine, ex.Message), ex)
        End Try

    End Function

    Public Function GetSingleEnumValueDescription(value As TestEnum) As String
        Try
            Dim attributes As DescriptionAttribute() = CType(value.GetType().GetField(value.ToString()).GetCustomAttributes(GetType(DescriptionAttribute), False), DescriptionAttribute())
            Return attributes(0).Description

        Catch ex As Exception
            Throw New Exception(String.Format("Error obteniendo los valores del enum '{0}'.{1}{2}", GetType(TestEnum).Name, vbNewLine, ex.Message), ex)
        End Try

    End Function
End Class

Public Class EnumValueDescription


#Region "Value"

    Private _Value As [Enum]

    Public Property Value() As [Enum]
        Get
            Return _Value
        End Get
        Set(ByVal value As [Enum])
            _Value = value
        End Set
    End Property

#End Region

#Region "Description"

    Private _Description As String

    Public Property Description() As String
        Get
            Return _Description
        End Get
        Set(ByVal value As String)
            _Description = value
        End Set
    End Property

#End Region

End Class

Public Enum TestEnum
    <Description("A Desc")> A
    <Description("B Desc")> B
    <Description("C Desc")> C
    <Description("D Desc")> D
End Enum

Public Class PropertyGridDataModel
    Public Property Id As Integer
    Public Property Name As String
    Public Property TestEnum As TestEnum
End Class

I am also attaching a short video showing the result on my end.

Regards,
Hristo
Progress Telerik