1. VB.NET Additional Topics
Programming In
Visual Basic.NET

2. Timer Control Place the control from the Toolbox on the form
Appears in the Component Tray
Prefix – tmr
Interval property
Between 0 and 65,535 milliseconds
1,000 milliseconds = 1 second
Enabled property
False (default) ==> Do not run Tick event
True ==> Run Tick event at designated interval
Tick event
Runs as a loop, with iterations repeated every time the designated Interval elapses
© 2001 by The McGraw-Hill Companies, Inc. All rights reserved.

3. Moving Controls with Timer
Use SetBounds to move or change size of a control
Example: Moving control with Timer
ctrName.SetBounds(intX, intY, intWidth, intHeight)
Private Sub tmrMove_Tick(ByVal sender As Object, ByVal e As System.EventArgs) Handles tmrMove.Tick
Const intSHIFT As Integer = 3I
If mintX <= 400 And mintY <= 400 Then
mintX += intSHIFT : mintY += intSHIFT
picPlane.SetBounds(mintX, mintY, 30, 30)
Else
mintX = 0 : mintY = 0
tmrMove.Enabled = False
End If
End Sub
© 2001 by The McGraw-Hill Companies, Inc. All rights reserved.

4. MDI versus SDI SDI = Single-Document Interface
All we have created thus far
Each form is in a separate window that acts independently form the other forms
MDI = Multiple-Document Interface
Like Word, Excel, etc.
Forms display within the window of other forms
© 2001 by The McGraw-Hill Companies, Inc. All rights reserved.

5. Examining an MDI Application
© 2001 by The McGraw-Hill Companies, Inc. All rights reserved.

6. MDI (Multiple-Document Interface)
Parent form (main window) which "contains" other windows
Many Child forms (document windows) "contained within" Parent window
Parent and and active Child share menus
Window menu
Tile, Cascade, Arrange Icons, and Window List
© 2001 by The McGraw-Hill Companies, Inc. All rights reserved. 4

7. MDI Environments Close Parent and all Child forms close also
Child forms not allowed to "wander" out of the Parent's area; Child ALWAYS inside Parent
Can combine MDI and SDI in VB
Splash forms are usually not child forms
Can have several documents open at one time accessible from Window menu
© 2001 by The McGraw-Hill Companies, Inc. All rights reserved.

8. Creating MDI Projects At design time designate a form as Parent
IsMdiContainer property = True
At run time designate Child forms
Before displaying the Child form from the Parent set the Child's MdiParent property to the parent form
Add a Window menu
frmChildOne.MdiParent = Me
© 2001 by The McGraw-Hill Companies, Inc. All rights reserved. 5

9. Designating Child Form
Private Sub mnuDisplayChildOne_Click(ByVal sender _ As System.Object, ByVal e As System.EventArgs) _ Handles mnuDisplayChildOne.Click
'Display Child One
Dim frmChildOne As New frmChildOne( )
frmChildOne.MdiParent = Me
frmChildOne.Show
End Sub
© 2001 by The McGraw-Hill Companies, Inc. All rights reserved.

10. Adding a Window Menu Parent form should include a Window menu to
Allow the user to arrange multiple Child forms
Allow the user to switch between windows
Lists open Child forms set menu's MdiList Property to True
© 2001 by The McGraw-Hill Companies, Inc. All rights reserved.

11. Window Menu Arrange Options
Use the LayoutMdi method to set the type of layout
Examples
Me.LayoutMdi(MdiLayout.TileHorizontal)
Me.LayoutMdi(MdiLayout.TileVertical)
Me.LayoutMdi(MdiLayout.Cascade)
© 2001 by The McGraw-Hill Companies, Inc. All rights reserved.

12. Displaying the Date and Time
Now property holds system date and time
Use DateTime methods:
Generally set initial values in Form_load and use Timer to update the time
Now.ToShortDateString
Now.ToLongDateString
Now.ToShortTimeString
Now.ToLongTimeString
lblDate.Text = Now.ToShortDateString
lblTime.Text = Now.ToShortTimeString
© 2001 by The McGraw-Hill Companies, Inc. All rights reserved.

13. Calendar Controls DateTimePicker MonthCalendar
© 2001 by The McGraw-Hill Companies, Inc. All rights reserved.

14. DateTimePicker Control
Value Property
Contains the date
Initially set to current date
User can select a date or your program can assign a date
ValueChanged Event
Prefix - dtm
© 2001 by The McGraw-Hill Companies, Inc. All rights reserved.