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1. Sep-05 Slide:1
ActiveX Controls in VB
ActiveX Controls in VB6

2. Sep-05 Slide:2
ActiveX Controls in VB
What are ActiveX Controls?
•Custom UI Controls
•Which you can design and add to the toolbox
•And then use in applications

3. Sep-05 Slide:3
ActiveX Controls in VB
Creating Simple ActiveX Controls
•Start with New Project.. ActiveX Control
•Design/program as if a form
•Add a project to Group – test it in that
•Finally, produce a compiled OCX file
•For example, a simple clock control..

4. Sep-05 Slide:4
ActiveX Controls in VB
The Clock Control 1

5. Sep-05 Slide:5
ActiveX Controls in VB
Clock Control 2
•It will work by having a Timer
•Which ticks every second
•And gets system time
•And displays it in a label

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ActiveX Controls in VB
Clock Control 3

7. Sep-05 Slide:7
ActiveX Controls in VB
Clcok Control 4 - Testing

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ActiveX Controls in VB
Clock Control 5 – Normal exe project added

9. Sep-05 Slide:9
ActiveX Controls in VB
Clock Control 6 – Set Test as Startup
Or when you Run it it will
start in a browser

10. Sep-05 Slide:10
ActiveX Controls in VB
Clock Control 7 – The control in
use

11. Sep-05 Slide:11
ActiveX Controls in VB
Clock control 7 – Give it a
name

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ActiveX Controls in VB
Clock Control 8 – Make .ocx
file

13. Sep-05 Slide:13
ActiveX Controls in VB
Clock Control 8 – Adding Control in a new project

14. Sep-05 Slide:14
ActiveX Controls in VB
ActiveX Exercise 1
•Make a Clock control like this but..
•Have 3 fields showing hour, minute and second
•Use hour() minute() and second() functions

15. Sep-05 Slide:15
ActiveX Controls in VB
Controls with properties
•Most controls have properties used for design
•Example background colour of textbox
•And properties for user input
•Such as text in a text box
•ActiveX usually need the same

16. Sep-05 Slide:16
ActiveX Controls in VB
ActiveX Controls are like Classes (as are forms)
•They have methods
•They have private data members
•They have property let and get routines
•Can set up events

17. Sep-05 Slide:17
ActiveX Controls in VB
Two 'users' of custom controls
•One user is the programmer who uses the control
in a form design
•The other is the final end-user who uses that form
•You have to write code for both types of user

18. Sep-05 Slide:18
ActiveX Controls in VB
Properties modified at design-time
•Need public property Let and Get
•and private data member for internal
representation
•But
•property values differ between control instances
•and must 'persist' when Form not in memory
•so must be written to disc somehow
•actually stored in the .frm file
•this persistence is not automated

19. Sep-05 Slide:19
ActiveX Controls in VB
Example – a spinner control
•Input integer values
•Buttons to increase/decrease value
•Need a StepSize property

20. Sep-05 Slide:20
ActiveX Controls in VB
End-user code
Private Sub Command1_Click()
Text1.Text = CInt(Text1.Text) + StepSize
End Sub
Private Sub Command2_Click()
Text1.Text = CInt(Text1.Text) - StepSize
End Sub

21. Sep-05 Slide:21
ActiveX Controls in VB
Dim ssize As Integer
Public Property Let StepSize(val As Integer)
ssize = val
PropertyChanged "StepSize"
End Property
Public Property Get StepSize() As Integer
StepSize = ssize
End Property
Private Sub UserControl_WriteProperties(PropBag As PropertyBag)
PropBag.WriteProperty "StepSize", StepSize, 0
End Sub
Private Sub UserControl_ReadProperties(PropBag As PropertyBag)
StepSize = PropBag.ReadProperty("StepSize", 0)
End Sub
Private Sub UserControl_Initialize()
Text1.Text = 0
End Sub
Designer-user code

22. Sep-05 Slide:22
ActiveX Controls in VB
Designer use

23. Sep-05 Slide:23
ActiveX Controls in VB
.FRM contents
VERSION 5.00
Object = "*\AspinnerProject.vbp"
Begin VB.Form Form1
..
ScaleWidth = 4680
StartUpPosition = 3 'Windows Default
Begin Project1.UserControl1 UserControl12
Height = 855
Left = 840
..
_ExtentY = 1508
StepSize = 9
End
Begin Project1.UserControl1 UserControl11
Height = 855
..
_ExtentY = 873
StepSize = 5
End
End
..

24. Sep-05 Slide:24
ActiveX Controls in VB
ActiveX Exercise 2
•Write a 'slider' control for numeric input
•When user drags mouse from area,
input is mouse Y
•Have textbox and pictureBox
•Program the mouseMove event of the
PictureBox, use the Y parameter
•Once working.. add a scale property set
at design-time
•Then expose a 'Value' property which
allows access to the number in the (Let
and Get) and read/write

25. Sep-05 Slide:25
ActiveX Controls in VB
Adding Events to controls
•A control can make an event occur
•This would be a 'custom' event for the control
•Designer can then program an event-handler for
it
•For example, in the spinner control, could hav ea
BadKey event if non-digit key pressed..

26. Sep-05 Slide:26
ActiveX Controls in VB
Control with Event
..
Public Event Badkey()
..
Private Sub Text1_KeyDown(KeyCode As Integer, Shift As Integer)
If KeyCode = 13 Or KeyCode = 8 Then Exit Sub 'Enter or backspace
If KeyCode < 48 Or KeyCode > 57 Then ' not 0 to 9
RaiseEvent Badkey
End If
End Sub

27. Sep-05 Slide:27
ActiveX Controls in VB
Designer writes event-handler

28. Sep-05 Slide:28
ActiveX Controls in VB
ActiveX Control Exercise 3
•Add a 2Click event to the slider control
•Triggered when picturebox double-clicked
•As designer, use it to zero the value