1. Chapter 13 Additional Topics in Visual Basic
Programming In
Visual Basic .NET

2. Advanced Validation Techniques
.NET ErrorProvider components
Share some characteristics with Web validation controls
Set MaxLength and/or CharacterCasing properties of text boxes
Perform field-level validation using Validating event of input controls
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

3. The ErrorProvider Component
ErrorProvider component causes an error indication to appear next to the field in error
Generally, one ErrorProvider can be used to validate all controls on a form
If data value is invalid, a blinking icon displays next to the field in error and a message displays in a pop-up (similar to a ToolTip)
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

4. ErrorProvider.SetError Method
General Form
Examples
ErrorProviderObject.SetError(ControlName, MessageString)
ErrorProvider1.SetError(quantityTextBox, "Quantity must be numeric.") ErrorProvider1.SetError(creditCardTextBox, "Required field.")
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

5. The MaxLength and CharacterCasing Properties
Helps user to enter correct input data
MaxLength property
Set maximum number of characters that can be entered, beeps and holds insertion point to indicate error
CharacterCasing property
Converts each character entered to Normal, Upper or Lower case (default is Normal)
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

6. Field-Level Validation
Displays any error message as soon as the user attempts to leave a field with invalid data
To accomplish field-level validation use
Validating event
CausesValidation property
ErrorProvider components
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

7. Using the Validating Event and CausesValidation Property
Validation event is best location for validation code
Use CancelEventsArgs argument to cancel the event and return focus to the control
Each control on a form has a CausesValidation property set to True by default
When focus passes from one control to another, the validating event occurs for the control just left
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

8. Multiple Document Interface
SDI = Single document interface
All we have created thus far
Each form in the project acts independently from the other forms (such as Splash form)
MDI = Multiple document interface
An example of an MDI application is Word
Word has a parent form (the main window) and child forms (each document window)
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

9. Multiple-Document Interface (continued)
Child form always stays within boundaries of the parent window
Close the parent window and all child windows close automatically
Child form always appears inside parent’s area
Window menu displays list of open windows, allows movement from one active document to another
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved. 4

10. MDI Application Forms
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

11. Creating an MDI Project
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 current (parent) form
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved. 5

12. Child Form Code Example
Private Sub displayChildOneMenuItem_Click(ByVal sender As _
System.Object, ByVal e As System.EventArgs) Handles _
displayChildOneMenuItem.Click
' Display Child One form.
Dim childOneForm As New childOneForm( )
childOneForm.MdiParent = Me
childOneForm.Show( )
End Sub
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

13. Creating an MDI Project (continued)
If multiple child windows are displayed, the title bar of each child should be unique
Solution
Append a number to the title bar before displaying the form (like MS Word)
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

14. MDI Child Title Bar Example
' Module-level declarations.
Dim childOneCountInteger As Integer
Private Sub displayChildOneMenuItem_Click(ByVal sender As _
System.Object, ByVal e As System.EventArgs) Handles _
displayChildOneMenuItem.Click
' Display Child One form.
Dim childOneForm As New childOneForm
childOneForm.MdiParent = Me
childOneCountInteger += 1
childOneForm.Text = "ChildOne Document " _
& childOneCountInteger.ToString( )
childOneForm.Show( )
End Sub
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

15. Adding a Window Menu Parent form should include a Window menu to
List open Child forms (Set menu's MdiList property to True)
Allow the user to arrange multiple Child forms
Allow the user to switch between windows
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

16. Layout Options
Use an argument of the LayoutMdi method to set the type of layout
Examples
Me.LayoutMdi(MdiLayout.TileHorizontal)
Me.LayoutMdi(MdiLayout.TileVertical)
Me.LayoutMdi(MdiLayout.Cascade)
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

17. Toolbars and Status Bars
Enhance usability of programs
A toolbar requires a toolbar control and an image list component
Toolbars are an easy shortcut for menu items
Image list holds the graphics that appear on toolbar buttons
Status bars appear at bottom of screen and display information for the user
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

18. Image Lists
Toolbar control requires its images to be stored in an image list
Add an ImageList component to the form
Locate the Images property, click the Builder (ellipses) button to open the Image Collection Editor
Click on the Add button to add images
An index is automatically assigned to each image in the collection
Use the index to assign the pictures to the toolbar buttons
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

19. Image Collection Editor
Image index
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

20. Toolbars Place the ToolBar object on the form
Assign the image list component for the form to the ImageList property of the toolbar
Add buttons to the toolbar using the ToolBarButton Collection Editor
Set properties for new buttons in the right pane of the editor
A Toolbar has a single ButtonClick event, use the event arguments to determine which button was clicked
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

21. ToolBarButton Collection Editor
Contains two Buttons
Assigning the Image for the Button Face
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

22. Coding for the Toolbar
The toolbar has a single ButtonClick event that occurs when the user clicks any of the buttons
Use the event arguments to determine which button was clicked
Each button has an Index
Example
ToolBar1.Buttons.IndexOf(e.Button)
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved. 20

23. Toolbar Code Example
Private Sub parentToolbar_ButtonClick(ByVal sender As _
System.Object, ByVal e As _
System.Windows.Forms.ToolbarButtonClickEventArgs) _
Handles parentToolbar.ButtonClick
' Execute appropriate procedure for button clicked.
Select Case parentToolbar.Button.IndexOf(e.Button)
Case 0
displayChildOneMenuItem_Click(sender, e)
Case 1
displayChildTwoMenuItem_Click(sender, e)
End Select
End Sub
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

24. Status Bars
Usually located at the bottom of a form to display date, time, status of CapsLock or NumLock, error or informational messages
Place the StatusBar control on the form
Add StatusBarPanel objects to the Status Bar
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

25. Status Bars (continued)
ShowPanels property
False by default, only displays Text property of Status Bar
Set to True to show Panels
Panels Collection
Click Add button in the StatusBarPanel Collection Editor to add a panel
Set Panel properties in the right pane of Editor window
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

26. StatusBarPanel Collection Editor
Contains two Panels
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

27. Assigning Values to Panels
Assign values to the Text property at run time
Examples
dateStatusBarPanel.Text = Now.ToShortDateString( )
timeStatusBarPanel.Text = Now.ToLongTimeString( )
informationStatusBarPanel.Text = "It’s very late."
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

28. Displaying the Date and Time
Use the properties and methods of the DateTime structure to retrieve and format the current date and time
Now property holds system date and time in numeric format
Generally set initial values in Form_load event and use a Timer component to update the time
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

29. Displaying the Date and Time (continued)
DateTime methods
ToShortDateString
ToLongDateString
ToShortTimeString
ToLongTimeString
Actual display depends on the user's local system settings.
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

30. Some Helpful Date Controls
Provide the ability to display calendars on your form
DateTimePicker
Takes less screen space
Displays only day and date unless user drops down the calendar
MonthCalendar
Displays calendar
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

31. Calendar Controls DateTimePicker MonthCalendar
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

32. DateTimePicker Control
Value Property
Contains the date
Initially set to current date
User can select a date or you can assign a date value to the property
ValueChanged Event
Allows use of all the properties of the system time on the Value property of the control
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

33. Crystal Reports
Gallery contains "experts" for guidance in creating standard reports, forms and mailing labels
May use an existing report or generate a new one
Publish reports on Windows Forms or on Web Forms
Note: Visual Basic .NET Standard Edition does not include Crystal Reports.
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

34. Create and Display a Report
Add a Report Designer
Design the Report Template which includes
Settings for connection to the database
Layout of the report
Add a CrystalReportViewer control to a form
Connect the control to the template
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

35. Adding a Report Designer
Select Project menu, Add New Item
Choose Crystal Report icon
Name the report
Choose type of report
Using the Report Expert (opens a wizard)
As a Blank Report
From an Existing Report
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

36. Add New Crystal Report Item
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

37. Crystal Report Gallery
Often the easiest way to create a report
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

38. Standard Report Expert Wizard
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

39. Standard Report Expert Wizard – Select Table
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

40. Standard Report Expert Wizard - Select Fields
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

41. Display the Report Add a CrystalReportViewer control to the form
ReportSource Property
Set to Report file name using Browse option
Anchor Property
Set for all four edges to allow control to resize, if the form is resized
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

42. The Report Designer Two new toolbars Field Explorer window
Use to add new fields to report
Separate section in toolbox
Use items to add elements such as lines, boxes or text not bound to a data field
Template contains several bands for information (see Figure on next slide)
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

43. Crystal Reports Layout in Report Designer
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

44. The Report Designer (continued)
Report Header
Information which appears on only the first page of a multipage report
Page Header
Information which appears at top of each page
Generally, report title and column headings
Details Section
Data for body of report
Fields which appear on each line of report (each record)
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

45. The Report Designer (continued)
Report Footer
Information which appears once at the end of the report
Page Footer
Information which appears at the bottom of each page
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

46. Modifying Report Design
Move, resize and reformat fields in the designer
Resize by using sizing handles
Drag the field control to move it
To reformat a field, right-click and select Format from the shortcut menu
Select Report Expert from context menu to change the report design
Select Style Expert to choose a new style
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

47. Adding a Report to a Web Form
Use the CrystalReportsViewer control from the Web Forms section of the toolbox
Web version does not have printer options
Set the ReportSource property in the Web Form’s Page_Load event
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.

48. Moving a Crystal Reports Project
Change the data source for the report template
Browse to current location of database file
Change ReportSource property of the CyrstalReportViewer control
Browse to locate project’s current folder
© 2005 by The McGraw-Hill Companies, Inc. All rights reserved.