wpf - vb - animating gridsplitter / dock panel - wpf

Question

this relates to my earlier question - I want to animate a grid splitter (to make panels slide into / out of view). We are pretty good at VB and already have a VB project, so would like to stay with VB if we can, but most WPF examples seem to be in XAML or CS.
I have some simple VB animation code working, BUT:
Of course, what needs to be animated is the width / height of the grid column / row, and this is not a dependency property. I found some clever stuff in CS to make a dependency property but could not translate this to vb. So I found a simple workaround which is to animate a dockpanel in the grid cell, catch it's size changed events and use these to set the cell grid size. It works but I wonder if it's less efficient as 2 things are being changed separately? Also I have to (when the animation completes) set the grid cells sizes back to * in the right proportion, and the dockpanel size back to auto.
It works, but it seems a bit clumsy - does someone have an example of making the animation for the grid work directly from VB any any other suggestions?
Thanks

Answer 1

For reference, here is the VB code for a dependency property to animate a gridsplitter:
Public Class GridLengthAnimation
Inherits AnimationTimeline
Public Sub New()
End Sub
Public Property From() As GridLength
Get
Return DirectCast(GetValue(FromProperty), GridLength)
End Get
Set(value As GridLength)
SetValue(FromProperty, value)
End Set
End Property
Public Shared ReadOnly FromProperty As DependencyProperty
= DependencyProperty.Register("From", GetType(GridLength),
GetType(GridLengthAnimation))
Public Property [To]() As GridLength
Get
Return DirectCast(GetValue(ToProperty), GridLength)
End Get
Set(value As GridLength)
SetValue(ToProperty, value)
End Set
End Property
Public Shared ReadOnly ToProperty As DependencyProperty
= DependencyProperty.Register("To", GetType(GridLength),
GetType(GridLengthAnimation))
Public Overrides ReadOnly Property TargetPropertyType() As Type
Get
Return GetType(GridLength)
End Get
End Property
Protected Overrides Function CreateInstanceCore() As Freezable
Return New GridLengthAnimation()
End Function
Public Overrides Function GetCurrentValue
(defaultOriginValue As Object,
defaultDestinationValue As Object,
animationClock As AnimationClock) As Object
Dim fromValue As Double = Me.From.Value
Dim toValue As Double = Me.[To].Value
If fromValue > toValue Then
Return New GridLength((1 - animationClock.CurrentProgress.Value)
* (fromValue - toValue) + toValue,
If(Me.[To].IsStar, GridUnitType.Star, GridUnitType.Pixel))
Else
Return New GridLength((animationClock.CurrentProgress.Value) *
(toValue - fromValue) + fromValue,
If(Me.[To].IsStar, GridUnitType.Star, GridUnitType.Pixel))
End If
End Function
End Class