Will this work for a user control Property?

[MrPeanut]

Hey all,

I have a control and for this control I want to create a property (eg. 'ItemName'). During design time I want the property to have a list of options that are populated from a Dataset. Is this possible?

I know I could use an Enumeration for the property list, but the values in the list are not static so the enumeration will not work.

Thanks in advance!

 

[SBendBuckeye]

You will need a custom designer class to do this. See MSDN for IDesigner and DesignerAttribute. Sorry, I don't have time to post any examples other than the one below from MSDN. Hopefully this will get you started. Good Luck!

Imports System
Imports System.Collections
Imports System.ComponentModel
Imports System.ComponentModel.Design
Imports System.Drawing
Imports System.Windows.Forms

' ms-help://MS.VSCC.v80/MS.MSDN.v80/MS.NETDEVFX.v20.en/cpref3/html/T_System_ComponentModel_Design_IDesigner.htm

' A DesignerAttribute associates the example IDesigner with an example control.
<DesignerAttribute(GetType(ExampleIDesigner))> _
Public Class TestControl
    Inherits System.Windows.Forms.UserControl

    Public Sub New()
    End Sub
End Class

<System.Security.Permissions.PermissionSetAttribute(System.Security.Permissions.SecurityAction.Demand, Name:="FullTrust")> _
Public Class ExampleIDesigner
    Implements System.ComponentModel.Design.IDesigner

    ' Local reference to the designer's component.
    Private component_ As IComponent

    ' Public accessor to the designer's component.
    Public ReadOnly Property Component() As System.ComponentModel.IComponent Implements IDesigner.Component
        Get
            Return component_
        End Get
    End Property

    Public Sub New()
    End Sub

    Public Sub Initialize(ByVal component As System.ComponentModel.IComponent) Implements IDesigner.Initialize
        ' This method is called after a designer for a component is created,
        ' and stores a reference to the designer's component.
        Me.component_ = component
    End Sub

    ' This method peforms the 'default' action for the designer. The default action 
    ' for a basic IDesigner implementation is invoked when the designer's component 
    ' is double-clicked. By default, a component associated with a basic IDesigner 
    ' implementation is displayed in the design-mode component tray.
    Public Sub DoDefaultAction() Implements IDesigner.DoDefaultAction
        ' Shows a message box indicating that the default action for the designer was invoked.
        MessageBox.Show("The DoDefaultAction method of an IDesigner implementation was invoked.", "Information")
    End Sub

    ' Returns a collection of designer verb menu items to show in the 
    ' shortcut menu for the designer's component.
    Public ReadOnly Property Verbs() As System.ComponentModel.Design.DesignerVerbCollection Implements IDesigner.Verbs
        Get
            Dim verbs_ As New DesignerVerbCollection()
            Dim dv1 As New DesignerVerb("Display Component Name", New EventHandler(AddressOf Me.ShowComponentName))
            verbs_.Add(dv1)
            Return verbs_
        End Get
    End Property

    ' Event handler for displaying a message box showing the designer's component's name.
    Private Sub ShowComponentName(ByVal sender As Object, ByVal e As EventArgs)
        If Not (Me.Component Is Nothing) Then
            MessageBox.Show(Me.Component.Site.Name, "Designer Component's Name")
        End If
    End Sub

    ' Provides an opportunity to release resources before object destruction.
    Public Sub Dispose() Implements IDisposable.Dispose
    End Sub

End Class

 

[MrPeanut]

I forgot to mention this is for a Web Project. I can't use the System.Windows.Forms class library.

I was browsing around and people made mention to using the UITypeEditor and I'm wondering within that, how would I allow the property to set it's values to that of the record set?

The code I have so far:

Imports System.Web
Imports System.Data
Imports System.Data.Common
Imports System.ComponentModel
Imports System.Drawing.Design
Imports Microsoft.Practices.EnterpriseLibrary.Data
Imports Microsoft.Practices.EnterpriseLibrary.Common
Imports System.Security.Permissions

Namespace MyControls

    Public Class PropertyDropDownListEditor
        Inherits System.Drawing.Design.UITypeEditor

        Public Overrides Function GetEditStyle(ByVal context As _
                                       ITypeDescriptorContext) As UITypeEditorEditStyle
            Return UITypeEditorEditStyle.DropDown
        End Function

        Public Overloads Overrides _
              Function EditValue(ByVal context As ITypeDescriptorContext, _
                                 ByVal provider As IServiceProvider, _
                                 ByVal value As Object) As Object

            If context Is Nothing _
                OrElse provider Is Nothing _
                OrElse context.Instance Is Nothing Then
                Return MyBase.EditValue(provider, value)
            End If

            Try
                'Put Data here to populate property's list values?  IF so that's where I need some help.

            Catch ex As Exception
                Throw New Exception(ex.Message)
            End Try
            Return MyBase.EditValue(context, provider, value)
        End Function

    End Class

<-- more code -->
End Namespace

 

[Sorwen]

How I do it for other things is make a collection of a class. Make a class that will contain all of the information you need for a record and then make a collection of that class on the control. You could also make a collection of structures/objects. Really there are a lot of ways you could do it. I tend to use classes rather than structures because I usually end up adding my own events to that class.

-I hate Microsoft!
-Forever and always forward.

 

[MrPeanut]

Hey all,

I tried creating Array List with all the values and in Design Time when I click the property I get a blank screen displayed. The Object collection Editor is blank.

I want to make it so during design when I click the proprty in the Propertygrid it will display the values of my list.

    Public NotInheritable Class MyTextBox
        Inherits System.Web.UI.WebControls.TextBox

        Public _FieldNames As ArrayList

        Public Property FieldNameList() As ArrayList
            Get
                Return _FieldNames
            End Get
            Set(ByVal value As ArrayList)
                _FieldNames = value
            End Set
        End Property


        Public Function RetrieveNames() As DataSet
            Dim Ds As New DataSet
            Dim db As Database = DatabaseFactory.CreateDatabase()
            Dim dbcInsert As DbCommand = db.GetStoredProcCommand("GetNames")

            Try
                Ds = db.ExecuteDataSet(dbcInsert)
                Return Ds

            Catch ex As Exception
                Throw New Exception(ex.Message)
            End Try

        End Function

        Public Function CreateNameList() As ArrayList
            Dim returnList As New ArrayList()
            Dim ds As DataSet
            Dim i As Integer


            'Obtain the list of FieldNames into a dataset
            ds = RetrieveNames()
            Try

                'Read through the Dataset and populate the ArrayList
                For i = 0 To ds.Tables(0).Rows.Count - 1
                    returnList.Add(ds.Tables(0).Rows(i).Item(i).ToString())
                    Console.WriteLine(returnList.Item(i).ToString())
                Next

                Return returnList

            Catch ex As Exception
                Throw New Exception(ex.Message)
            End Try

        End Function

        Protected Overrides Sub OnPreRender(ByVal e As System.EventArgs)
            FieldNameList = CreateNameList()
            MyBase.OnPreRender(e)
        End Sub

 

[Sorwen]

I want to make it so during design when I click the proprty in the Propertygrid it will display the values of my list.

If you figure that out let me know because I've only had simple properties (string/int/etc) show up. Things like arrays/collections/never do.

-I hate Microsoft!
-Forever and always forward.