如何自定义一个VB.NET控件类

Public Class TextAndButton
    Public Event TextClick(ByVal sender As Object, ByVal e As System.EventArgs)
    Public Event ButClick(ByVal sender As Object, ByVal e As System.EventArgs)
    Public Delegate Sub mydelegate(ByVal sender As Object, ByVal e As System.EventArgs)
    '文本框获得焦点
    Private Sub TextBox_GotFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox.GotFocus
        Dim mypoint As New Drawing.Point()
        mypoint.X = TextBox.Location.X + TextBox.Size.Width - Button.Size.Width - 1
        mypoint.Y = TextBox.Location.Y + TextBox.Size.Height - Button.Size.Height - 1
        Button.Location = mypoint
        Button.Visible = True
    End Sub
    '文本框失去焦点
    Private Sub TextBox_LostFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox.LostFocus
        If Me.Button.Focused Then
        Else
            Button.Visible = False
        End If
    End Sub
    'button失去焦点
    Private Sub Button_LostFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button.LostFocus
        TextBox.Focus()
    End Sub
    Private Sub Button_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button.Click
        RaiseEvent ButClick(sender, e)
    End Sub
    Private Sub TextBox_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox.Click
        RaiseEvent TextClick(sender, e)
    End Sub
End Class