[RESOLVED] Using properties of a hosted control in the Designer

[Mark@SF]

I have created a custom TextProgressBar that is an item in the StatusStrip drop-down list and is hosted via the ToolStripControlHost. I would like to expose the TextProgressBar properties Minimum, Maximum, and Step in the Designer.

Here are the 2 classes (ToolStripTextProgressBar and TextProgressBar):

Imports System.Windows.Forms.Design '...required for ToolStripItemDesignerAvailability
<ToolStripItemDesignerAvailability(ToolStripItemDesignerAvailability.ToolStrip Or ToolStripItemDesignerAvailability.StatusStrip)>
Public Class ToolStripTextProgressBar

    Inherits ToolStripControlHost

    '...call the base constructor passing in a TextProgressBar instance
    Public Sub New()
        MyBase.New(New TextProgressBar)
        CType(Control, TextProgressBar).Style = ProgressBarStyle.Continuous
    End Sub

    Public ReadOnly Property ProgressBarControl As TextProgressBar
        Get
            Return CType(Control, TextProgressBar)
        End Get
    End Property

    '...expose the ToolStripTextProgressBar.Value as a property (IDE Designer)
    Public Property Value As Integer
        Get
            Return Me.ProgressBarControl.Value
        End Get
        Set
            Me.ProgressBarControl.Value = Value
        End Set
    End Property

End Class

Public Class TextProgressBar

    Inherits ProgressBar

    Public Overrides Property Text As String
    '...http://www.pinvoke.net/default.aspx/Constants/WM.html
    '   WM_PAINT = x0F (decimal value = 15...CDec("&H0F") = 15)
    Private Const WmPaint = 15  '...occurs when the control needs repainting

    '...WndProc receives all messages directed to the current window. In order to
    '   avoid overwriting your text, make sure the default code executes first,
    '   then call the custom routine to display the overlaid text

    Protected Overrides Sub WndProc(ByRef m As System.Windows.Forms.Message)
        MyBase.WndProc(m)
        If m.Msg = WmPaint Then
            PaintText()
        End If
    End Sub

    Private Sub PaintText()

        Dim s As String = Text  '...this is the TextProgressBar.Text property
        Dim percent As Integer
        Dim textSize As SizeF

        '...display either a percentage or custom text
        If s = "" AndAlso Maximum - Minimum <> 0 Then
            '...display a percentage
            percent = CInt(100 * (Value - Minimum) / (Maximum - Minimum))
            s = percent.ToString & "%"
        Else
            '...display custom text
        End If

        '...get the graphics object and calculate drawing parameters based on the current Font specs
        Using g As Graphics = Me.CreateGraphics()
            textSize = g.MeasureString(s, Me.Font)
            Using b = New SolidBrush(ForeColor)
                g.DrawString(s, Me.Font, Brushes.Black, CSng(Me.Width / 2 - textSize.Width / 2), CSng(Me.Height / 2 - textSize.Height / 2))
            End Using
        End Using

        textSize = Nothing

    End Sub

End Class

I've successfully exposed the ToolStripTextProgressBar property Value as shown above in the ToolStripTextProgressBar class.

When I try to do the same for the Minimum or Maximum properties, they appear in the Designer as properties of the hosted ToolStripTextProgressBar, but the Designer will not accept a manual edit of the property.

    '...expose the ToolStripTextProgressBar.Minimum as a property (IDE Designer)
    Public Property Minimum As Integer
        Get
            Return Me.ProgressBarControl.Minimum
        End Get
        Set
            Me.ProgressBarControl.Minimum = Minimum
        End Set
    End Property

For example, when manually setting Minimum property to "1", the Designer immediately resets it to "0".

Note that I can set the Minimum property at runtime via the ProgressBarControl property of a ToolStripTextProgressBar:

tspbMainCountdown.ProgressBarControl.Minimum = 1

I need some help to figure this out. Thanks.

[jmcilhinney]

This is wrong:

    '...expose the ToolStripTextProgressBar.Minimum as a property (IDE Designer)
    Public Property Minimum As Integer
        Get
            Return Me.ProgressBarControl.Minimum
        End Get
        Set
            Me.ProgressBarControl.Minimum = Minimum
        End Set
    End Property

A property setter ALWAYS has a parameter named value and that is what you use in the setter. That parameter is generally implicit these days but you could make it explicit:

    '...expose the ToolStripTextProgressBar.Minimum as a property (IDE Designer)
    Public Property Minimum As Integer
        Get
            Return Me.ProgressBarControl.Minimum
        End Get
        Set(value As Integer)
            Me.ProgressBarControl.Minimum = Minimum
        End Set
    End Property

Your other property worked because the property itself was named Value. You thought you were using the property in the setter but you were actually using the parameter. You need to use that parameter in ALL setters:

    '...expose the ToolStripTextProgressBar.Minimum as a property (IDE Designer)
    Public Property Minimum As Integer
        Get
            Return Me.ProgressBarControl.Minimum
        End Get
        Set
            Me.ProgressBarControl.Minimum = Value
        End Set
    End Property

One thing you will find is that, if you include an explicit parameter then you can name it value but, if it's implicit, the VB code editor will change it to Value, i.e. change the casing.

[Mark@SF]

jmc -

Thanks! I've got the Minimum and Maximum properties working now.

I am getting a "Keyword is not valid as an identifier." error with the my code for the Step property:

    '...expose the ToolStripTextProgressBar.Step as a property (IDE Designer)
    Public Property Step As Integer
        Get
            Return Me.ProgressBarControl.Step
        End Get
        Set
            Me.ProgressBarControl.Step = Value
        End Set
    End Property

The compiler does not like the "Step" in the "Public Property Step As Integer" statement. Can you help me with this also?

[Mark@SF]

jmc -

Thanks! I've got the Minimum and Maximum properties working now.

I am getting a "Keyword is not valid as an identifier." error with the my code for the Step property:

    '...expose the ToolStripTextProgressBar.Step as a property (IDE Designer)
    Public Property Step As Integer
        Get
            Return Me.ProgressBarControl.Step
        End Get
        Set
            Me.ProgressBarControl.Step = Value
        End Set
    End Property

The compiler does not like the "Step" in the "Public Property Step As Integer" statement. Can you help me with this also?

[Mark@SF]

jmc -

I got it...enclosing "Step" in brackets was the solution:

    '...expose the ToolStripTextProgressBar.Step as a property (IDE Designer)
    Public Property [Step] As Integer
        Get
            Return Me.ProgressBarControl.Step
        End Get
        Set
            Me.ProgressBarControl.Step = Value
        End Set
    End Property

Thank you again for your help!