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Programming Visual Basic 2005
book

Programming Visual Basic 2005

by Jesse Liberty
September 2005
Intermediate to advanced
576 pages
14h 23m
English
O'Reilly Media, Inc.
Content preview from Programming Visual Basic 2005

The Compare Validator

While ensuring that the user has made an entry is very useful, you will often want to validate that the content of the entry is within certain guidelines. One of the most common requirements for validation is to compare the user's input to a constant, the value of another control, or a database value.

Add a new control to your bug-reporting dialog that will ask the user how many copies of the book he purchased. Manually type in a new row (using <tr><td> tags) above the Display Errors row, and set the prompt column to Number purchased:. The second column needs a text box (txtNumPurch), and the third column now takes two validators (just drag them both into the same column).

Summary and BulletList

Figure 9-11. Summary and BulletList

Message box with List

Figure 9-12. Message box with List

The validator first is a RequiredFieldValidator (ID = reqFieldNumPurch and Control-ToValidate=txtNumPurch.

The RequiredFieldValidator ensures that the user does not leave the entry blank. Finally, set its ErrorMessage property to Please enter the number of books purchased, and its Text property to an asterisk.

The second validator is of type CompareValidator (which you also find in the Validation tab in the Toolbox). You'll use this validator to ensure that the user does not enter the value zero. The properties of the CompareValidator ...

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Publisher Resources

ISBN: 0596009496Errata Page