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Visual C# | Validating forms exercise | Use the Validating event to check inputs
This exercise is provided to allow potential course delegates to choose the correct Wise Owl Microsoft training course, and may not be reproduced in whole or in part in any format without the prior written consent of Wise Owl.
| Software ==> | Visual C# (79 exercises) |
| Version ==> | Any version of C# |
| Topic ==> | Validating forms (6 exercises) |
| Level ==> | Average difficulty |
| Subject ==> | C# training |
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This exercise asks you to validate form input. First add the existing form called frmNewHeart from the folder shown above into your project:
Call the ValidateChildren method when you click on the Apply button, but don't do anything else yet at this stage
Now attach code to the Validating event of the txtName textbox, to display a message if it has been left blank:
What your MessageBox could show
Do the same thing for the txtAge field, but for this check also that the age entered is a whole number:
You could use a try / catch clause or the TryParse method to do this
Everyone lies about their age: add code to the txtAge textbox's Validated event to increase the age after it has passed validation:
Make sure you tell the user that you don't trust him/her!
When everything's working OK, close the form down.