VB.NET 的picturebox问题
学用timer控件的时候，发现书上可以用的picturebox1.width随时间变化，在我的电脑上就不行，请问为什么啊，救我！！！！

Public Class Form1
    Inherits System.Windows.Forms.Form

    Public x As Integer = 10


    Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick

[color=FF0000]        PictureBox1.Width = PictureBox1.Width + x[/color]
''''''''''''''''''''''''''''就是上面这句话没有生效
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Timer1.Enabled = True        '使timer生效
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        Timer1.Enabled = False    '禁用timer
    End Sub
End Class