用Visual Studio 2008进行Silverlight开发

以下是引用片段：
Partial Public Class Page
Inherits Canvas
Private degrees As Integer = 0

　　在Page_Loaded()子程序里，为第二个Timeline增加一个新的duration：

以下是引用片段：
Public Sub Page_Loaded(ByVal o As Object, ByVal e As EventArgs)
' Required to initialize variables
InitializeComponent()
'---display the clock---
Me.Timeline1.Duration = New Duration(New TimeSpan(0, 0, 1))
Me.Timeline1.Begin()
'---rotate the clock---
Me.Timeline2.Duration = New Duration(New TimeSpan(100))
Me.Timeline2.Begin()
End Sub

　　这里，你设置了Timeline2的间隔为100毫秒(重载了TimeSpan对象构造器)。每100毫秒，Timeline2的Completed事件触发，这里你调用PerformTransformation()子程序：

以下是引用片段：
Private Sub Timeline2_Completed( _
ByVal sender As Object, _
ByVal e As System.EventArgs) _
Handles Timeline2.Completed
PerformTransformation()
Me.Timeline2.Begin()
End Sub

　　子程序使用RotateTransform对象来完成一个对象的变化。这里你使用它来在每个时刻旋转按钮1度。

以下是引用片段：
Private Sub PerformTransformation()
'---use a RotateTransform object to perform transformation---
Dim rt As New RotateTransform
'---define the transformation---
With rt
.Angle = degrees
.CenterX = 50
.CenterY = 50
End With
'---increment the degree of rotation---
degrees += 1
'---transform the button---
btnTime.RenderTransform = rt
End Sub