Expandable Props [RESOLVED]

Having them in separate class files or not should make no difference (they're all separate in mine.)

So in the GradientPanel class you have the GradientStyle property and it's in the
Set portion of that property where you want to call Invalidate to have the Panel redraw
itself when you change one of the component properties of GradientStyle.

Not quite. The GradientPanel class (inherits Panel) just has the OnPaint override and thats all. Then in the GradientStyle class I
have the expandable properties. shouldnt the 3 props be in the GradientPanel? Basically, the GradientPanel &
GradientStyle classes should be merged in order to get the MyBase or Me for invalidating?

I think we're getting crossed-wires here somewhere.

If GradientPanel is going to have a property called GradientStyle
which is of the type GradientStyle, then it will have a Get and Set accessor,
that's where you call the Invalidate, not in either the GradientStyle or GradientStyleConverter classes.

Here's a mock up of what your GradientPanel control would look like:

VB Code:

Imports System.ComponentModel
 
Public Class MyControl
   Inherits Panel
 
   Private _gradientStyle As New GradientStyle
 
   ' This is the property your control exposes that uses the 
   ' Expandable class type and converter
   <Browsable(True), _
    DesignerSerializationVisibility(DesignerSerializationVisibility.Content)> _
   Public Property GradientStyle() As GradientStyle
      Get
         Return _gradientStyle
      End Get
      Set(ByVal Value As GradientStyle)
         _gradientStyle = Value
         ' Need to call Invalidate Here to cause your
         ' control to redraw itself when the expandable
         ' properties change
         Me.Invalidate()
      End Set
   End Property
 
   ' Implement separate "ShouldSerialize" and "Reset" methods because of the 
   ' Complex nature of the expandable property type
   Private Function ShouldSerializeGradientStyle() As Boolean
      ' Return True to indicate the value is not default and should be persisted
      Return Not (_gradientStyle.GradientMode = LinearGradientMode.Mode1 AndAlso _gradientStyle.PanelColor1.Equals(Color.Red) AndAlso _gradientStyle.PanelColor2.Equals(Color.Blue))
   End Function
 
   Private Sub ResetGradientStyle()
      ' Reset the property to a default value
      _gradientStyle = New GradientStyle
   End Sub
 
   Protected Overrides Sub OnPaint(ByVal e As System.Windows.Forms.PaintEventArgs)
      ' This is where you use your control settings to redraw your control
      MyBase.OnPaint(e)
      Select Case _gradientStyle.GradientMode
         Case LinearGradientMode.Mode1
            e.Graphics.FillRectangle(Brushes.Red, New Rectangle(New Point(0, 0), Me.Size))
 
         Case LinearGradientMode.Mode2
            e.Graphics.FillRectangle(Brushes.Green, New Rectangle(New Point(0, 0), Me.Size))
 
         Case LinearGradientMode.Mode3
            e.Graphics.FillRectangle(Brushes.Blue, New Rectangle(New Point(0, 0), Me.Size))
 
      End Select
   End Sub
End Class

Regards,

- Aaron.

Thats what I thought it should be like. Instead I had two of the classes split. so thats why I dont have the me or
mybase when setting the props?

I am going to make the necessary mods and it will probably take a while since I dont want to mess it up and
loose what I have got so far. Its usually a pain to rollback source safe unless I do it to a new directory.

Thanks for all your help. I will post back when I finish the changes :thumb:

Ok, I got the CreateInstance procedure updated so I thought I would post it. I had to do a few mods since I am
using Option Strict and Explicit ON.

VB Code:

Public Overloads Overrides Function CreateInstance(ByVal context As System.ComponentModel.ITypeDescriptorContext, _
ByVal propertyValues As System.Collections.IDictionary) As Object
    ' Create a new instance of the Gradient Style 
    ' with the supplied property values
    Dim obj1 As Object = propertyValues("GradientMode")
    Dim obj2 As Object = propertyValues("PanelColor1")
    Dim obj3 As Object = propertyValues("PanelColor2")
 
    If obj1 Is Nothing Then obj1 = LinearGradientMode.ForwardDiagonal
    If obj2 Is Nothing Then obj2 = Color.Red
    If obj3 Is Nothing Then obj3 = Color.Blue
 
    Dim gs As New GradientStyle
    gs.GradientMode = CType(obj1, LinearGradientMode)
    gs.PanelColor1 = CType(obj2, Color)
    gs.PanelColor2 = CType(obj3, Color)
 
    Return gs
 
End Function

I'm "still" working on the modifications to merge the two classes together.
Hopefully this will be done real soon. :)

Aaron, you are a true Guru!!!

Thanks for solving the Reset issue and drawing issue!

I am implementing the changes tonight and can hopefully move forward "finally"!!!


Many Thanks,
Robert

Hey,

Very quick first post to thank you for this ridiculously helpful post - after 2 days of trawling the web, this solved my problem in a couple of hours (and it would have been even quicker if I'd read the whole post, rather than trying to second guess what was coming...).

Thanks again, and VBForums is my new favourite forum!
Dave.