VB.NET自定义标题栏拖动

'首先在form里添加一个panel容器
   Dim x1,x2,y1,y2 As Integer
  '鼠标左键按下后将x1,y1赋值
    Private Sub Panel1_MouseDown(ByVal sender As Object,ByVal e As System.Windows.Forms.MouseEventArgs) Handles pnlMove.MouseDown
        If e.Button = Windows.Forms.MouseButtons.Left Then
            x1 = e.X
            y1 = e.Y
        End If
    End Sub
  '拖动过程中不断对x2,y2赋值
    Private Sub Panel1_MouseMove(ByVal sender As Object,ByVal e As System.Windows.Forms.MouseEventArgs) Handles pnlMove.MouseMove
        If e.Button = Windows.Forms.MouseButtons.Left Then
            x2 = e.X
            y2 = e.Y
            Me.Left = Me.Location.X + (x2 - x1)  
            Me.Top = Me.Location.Y + (y2 - y1)         
        End If
    End Sub