Dynamic User Controls, Custom Properties

I created a User Control under VB.net and I want to add the control dynamically.  Thats all working.  I get the control added and I have managed to access the standard properties, however I am not able to access the Custom Properties I have defined on my User Control.  It has to do with the way I access the User Control.

Here is a copy of my user control:

Public Class TextBox
    Inherits System.Windows.Forms.UserControl

    Public Sub New()
        MyBase.New()

        'This call is required by the Windows Form Designer.
        InitializeComponent()

        'Add any initialization after the InitializeComponent() call

    End Sub

    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub

    Private components As System.ComponentModel.IContainer

    Friend WithEvents TextBox1 As System.Windows.Forms.TextBox
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.TextBox1 = New System.Windows.Forms.TextBox()
        Me.SuspendLayout()
        '
        'TextBox1
        '
        Me.TextBox1.Location = New System.Drawing.Point(10, 10)
        Me.TextBox1.Name = "TextBox1"
        Me.TextBox1.TabIndex = 0
        Me.TextBox1.Text = ""
        '
        'TextBox
        '
        Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.TextBox1})
        Me.Name = "TextBox"
        Me.Size = New System.Drawing.Size(120, 40)
        Me.ResumeLayout(False)

    End Sub

    Private bolValRequired As Boolean

    Public Overrides Property Text() As String
        Get
            Return TextBox1.Text
        End Get
        Set(ByVal strValue As String)
            TextBox1.Text = strValue
        End Set
    End Property

    Public Property ValRequired() As Boolean
        Get
            Return bolValRequired
        End Get
        Set(ByVal bolValue As Boolean)
            bolValRequired = bolValue
            If bolValue Then
                Me.TextBox1.BackColor = System.Drawing.Color.LightPink
            End If
        End Set
    End Property

End Class

And here is how I create the User Control on another Form:

        Dim TextBox As OOApp.TextBox = New OOApp.TextBox()

        TextBox.Location = New System.Drawing.Point(20, 20)
        TextBox.Name = "TextBox1"
        TextBox.TabIndex = 1
        TextBox.ValRequired = True

        Me.Controls.Add(TextBox)

Here is how I talk to the User Control:

        Dim objControl As Control

        For Each objControl In Me.Controls

               MsgBox(objControl.Name & " " & objControl.Text)

        Next

I can access objControl.Text. What I cant do is request objControl.ValRequired since its not a known property.  I need some sort of objControl.GetProperty("ValRequired"), but I dont see that. Any ideas

Also it would be nice to access the control by name "TextBox1".  Me.Controls("TextBox1") will not work since it just accepts integers. Thanks for any suggestions you can provide.

Matthew Krzan,
(NT4 & 2k) MCP, MCSE
(NT4) MCP+I, MCSE+I
MCDBA
ACISS Systems, Inc.

Answer this question

Dynamic User Controls, Custom Properties

venumadhav
Is there anyway to reference the Control by name rather than a loop Since its added programaticly. Thanks for your help.

Matthew Krzan,
(NT4 & 2k) MCP, MCSE
(NT4) MCP+I, MCSE+I
MCDBA
ACISS Systems, Inc.
williware
Not via the built-in Controls collection. You can either maintain your own collection of controls yourself, or (since you put the controls on the form in code), maintain references to the controls you'll need. I think the point here is that if you put the controls there yourself, you have a reference to each control already. Why maintain another reference

In other words, the Controls collection doesn't work the way you want. You'll need to either create one yourself, or use a different technique for referring to the controls.
JenniferS
Thanks Ken!

Matthew Krzan,
(NT4 & 2k) MCP, MCSE
(NT4) MCP+I, MCSE+I
MCDBA
ACISS Systems, Inc.
Jim McKay
Several problems so far. First of all, you named your control instance TextBox, not TextBox1 (which is what it appears you think you named it, from later comments). I would STRONGLY suggest not naming the variable the same as the type, in Visual Basic. It makes it extremely hard to read the code, and on top of that, naming your class the same as a built-in type (and not even inheriting from the type) is confusing, as well.

You can't access the ValRequired property in your loop because the control you're using as the loop enumerator is a Control, not a OOApp.TextBox. In order to "see" that property, you would need to cast the enumerator as the correct type. This is no different than if you have a CheckedListBox on the form, and you want to see the CheckedItems property in such a loop--you wouldn't be able to, because your enumerator is a plain old Control.

If you want to loop through all the controls and take different action based on the type of the control, you'll need some type of control structure (maybe a Select Case) that determines the type of the enumerator, and then does what you need to do based on the type. Something like this:

    Dim objControl As Control

    For Each objControl In Me.Controls
      MessageBox.Show(objControl.GetType.FullName)

      If TypeOf (objControl) Is OOApp.TextBox Then
        Dim x As OOApp.TextBox = DirectCast(objControl, OOApp.TextBox)
        MessageBox.Show(x.ValRequired)

      ElseIf TypeOf (objControl) Is Button Then
        Dim x As Button = DirectCast(objControl, Button)
        ' Get some property that only buttons have...
        MessageBox.Show(x.DialogResult)
      End If
    Next

I would suggest reconsidering naming your control TextBox, or at least, rather than making it a user control, simply make a new class that inherits from TextBox, and add your properties to it.
Dynamic User Controls, Custom Properties

Answer this question