Animate Color by Percentage

ColorAnimator.vb

Imports System.Reflection
Imports System.Threading.Tasks

Public Class ColorAnimator

    Public obj As New Object
    Dim boolStop As New List(Of System.Threading.CancellationTokenSource)
    Public Async Function Animate(ctrl As Control, prop As PropertyInfo, newColor As Color) As Threading.Tasks.Task
        Dim oldColor As Color
        Dim StopAni As New System.Threading.CancellationTokenSource
        For Each n In boolStop
            n.Cancel()
        Next
        boolStop.Add(StopAni)
        oldColor = CType(prop.GetValue(ctrl), Color)
        For index = 0 To 100 Step 5
            If StopAni.IsCancellationRequested Then Exit Function
            prop.SetValue(ctrl, Animate(oldColor, newColor, index))
            Application.DoEvents()
            Await Task.Delay(10)
        Next
    End Function


    Private Function Animate(oldcolor As Color, newcolor As Color, precentage As Integer
                 ) As Color
        Dim r, b, g As Integer
        Dim o_r As Integer = oldcolor.R, o_b As Integer = oldcolor.B, o_g As Integer = oldcolor.G
        Dim n_r As Integer = newcolor.R, n_b As Integer = newcolor.B, n_g As Integer = newcolor.G
        r = o_r + (n_r - o_r) * precentage / 100
        g = o_g + (n_g - o_g) * precentage / 100
        b = o_b + (n_b - o_b) * precentage / 100
        Return Color.FromArgb(r, g, b)
    End Function


End Class

form1.vb

Public Class Form1

    Dim dColorAnimator As New ColorAnimator


    Private Async Sub Panel1_MouseEnter(sender As Object, e As EventArgs) Handles Panel1.MouseEnter
        Await dColorAnimator.Animate(Panel1, Panel1.GetType().GetProperty("BackColor"), Color.Red)
    End Sub


    Private Async Sub Panel1_MouseLeave(sender As Object, e As EventArgs) Handles Panel1.MouseLeave
        Await dColorAnimator.Animate(Panel1, Panel1.GetType().GetProperty("BackColor"), Color.White)
    End Sub

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load

    End Sub
End Class