Error When trying to inherit TabControl - vb.net

Question

Hello guys i got the following error when trying to inherit tabcontrol: Base class 'System.Windows.Forms.TabControl' Specified for class 'Form1' cannot be different from the base class 'System.Windows.Forms.Form' of one of its other partial types!
Here is a picture: http://prntscr.com/3dqzd6
What im trying to make is a animated tab control. i Found a code but it was only for visual basic(I code in c# but this code was for vb only)
My code:
Public Class Form1
Inherits TabControl//Here i got the error
Dim OldIndex As Integer
Private _Speed As Integer = 9
Property Speed As Integer
Get
Return _Speed
End Get
Set(ByVal value As Integer)
If value > 20 Or value < -20 Then
MsgBox("Speed needs to be in between -20 and 20.")
Else
_Speed = value
End If
End Set
End Property
Sub New()
SetStyle(ControlStyles.AllPaintingInWmPaint Or ControlStyles.OptimizedDoubleBuffer Or ControlStyles.ResizeRedraw, True)
End Sub
Sub DoAnimationScrollLeft(ByVal Control1 As Control, ByVal Control2 As Control)
Dim G As Graphics = Control1.CreateGraphics()
Dim P1 As New Bitmap(Control1.Width, Control1.Height)
Dim P2 As New Bitmap(Control2.Width, Control2.Height)
Control1.DrawToBitmap(P1, New Rectangle(0, 0, Control1.Width, Control1.Height))
Control2.DrawToBitmap(P2, New Rectangle(0, 0, Control2.Width, Control2.Height))
For Each c As Control In Control1.Controls
c.Hide()
Next
Dim Slide As Integer = Control1.Width - (Control1.Width Mod _Speed)
Dim a As Integer
For a = 0 To Slide Step _Speed
G.DrawImage(P1, New Rectangle(a, 0, Control1.Width, Control1.Height))
G.DrawImage(P2, New Rectangle(a - Control2.Width, 0, Control2.Width, Control2.Height))
Next
a = Control1.Width
G.DrawImage(P1, New Rectangle(a, 0, Control1.Width, Control1.Height))
G.DrawImage(P2, New Rectangle(a - Control2.Width, 0, Control2.Width, Control2.Height))
SelectedTab = Control2
For Each c As Control In Control2.Controls
c.Show()
Next
For Each c As Control In Control1.Controls
c.Show()
Next
End Sub
Protected Overrides Sub OnSelecting(ByVal e As System.Windows.Forms.TabControlCancelEventArgs)
If OldIndex < e.TabPageIndex Then
DoAnimationScrollRight(TabPages(OldIndex), TabPages(e.TabPageIndex))
Else
DoAnimationScrollLeft(TabPages(OldIndex), TabPages(e.TabPageIndex))
End If
End Sub
Protected Overrides Sub OnDeselecting(ByVal e As System.Windows.Forms.TabControlCancelEventArgs)
OldIndex = e.TabPageIndex
End Sub
Sub DoAnimationScrollRight(ByVal Control1 As Control, ByVal Control2 As Control)
Dim G As Graphics = Control1.CreateGraphics()
Dim P1 As New Bitmap(Control1.Width, Control1.Height)
Dim P2 As New Bitmap(Control2.Width, Control2.Height)
Control1.DrawToBitmap(P1, New Rectangle(0, 0, Control1.Width, Control1.Height))
Control2.DrawToBitmap(P2, New Rectangle(0, 0, Control2.Width, Control2.Height))
For Each c As Control In Control1.Controls
c.Hide()
Next
Dim Slide As Integer = Control1.Width - (Control1.Width Mod _Speed)
Dim a As Integer
For a = 0 To -Slide Step -_Speed
G.DrawImage(P1, New Rectangle(a, 0, Control1.Width, Control1.Height))
G.DrawImage(P2, New Rectangle(a + Control2.Width, 0, Control2.Width, Control2.Height))
Next
a = Control1.Width
G.DrawImage(P1, New Rectangle(a, 0, Control1.Width, Control1.Height))
G.DrawImage(P2, New Rectangle(a + Control2.Width, 0, Control2.Width, Control2.Height))
SelectedTab = Control2
For Each c As Control In Control2.Controls
c.Show()
Next
For Each c As Control In Control1.Controls
c.Show()
Next
End Sub
Please help me!
-Christos

Answer 1

When you create a form the designer makes one named Form1 it has a Partial Class by the same name - this is where the generated code is maintained and should not be touched by you. This Form1 Inherits from System.Windows.Forms.Form and hence cannot be made to inherit from a TabControl. If you simply change the name of the class you have above that intends to be a Sub-Classed version of the TabControl then all would be well.
Public Class Form1
...
End Class
Partial Class Form1
'same class as above just allowed to be seperate
'they share the internal code
End Class
Your code should start like:
Public Class myTabControl : Inherits TabControl
'continue with sub classing