WISE OWL EXERCISES
VISUAL C# EXERCISES
- Creating forms (4)
- Coding form events (1)
- Laying out your code (2)
- C# variables (4)
- Enumerations and constants (2)
- Conditions (2)
- Modular code (3)
- Arrays (2)
- Looping (2)
- Files and folders (3)
- Properties in C# (3)
- Using lists (3)
- Validating forms (6)
- Toolbars, menus and status bars (1)
- FileDialogs and StreamReaders (1)
- Debugging and trapping errors (1)
- Introduction to DataGridViews (1)
- DataGridView events (3)
- Complex DataGridViews (2)
- Creating classes (2)
- The form as a class (1)
- Data structures (4)
- Inheritance (4)
- Interfaces (2)
- Delegates and events (2)
- Writing LINQ (1)
- Advanced LINQ (3)
- LINQ to SQL models (1)
- Writing LINQ to SQL (2)
- Grouping using LINQ (2)
Visual C# | Validating forms exercise | Validating name and age entered
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.
The answer to the exercise will be included and explained if you attend the course listed below!
You need a minimum screen resolution of about 700 pixels width to see our exercises. This is because they contain diagrams and tables which would not be viewable easily on a mobile phone or small laptop. Please use a larger tablet, notebook or desktop computer, or change your screen resolution settings.
Add the existing form shown above to your project - you should see this:
Initially there is no validation applied
Add code to the Validating event of the txtName textbox, so that if the user leaves the length of this textbox as zero you see an error message:
This is what you should see if you leave the name blank
Now do the same for the txtAge field, but this time check that it is a whole number:
The age must be filled in, and must be a whole number
The easiest way to do this is with a try ... catch ... clause, within which you attempt to convert the age filled in into an integer.
Finally, add code to the Age field's Validated event so that the age is increased by 10 years after it has been checked:
Acknowledge the fact that no one tells the truth about their age ...
You should now see that the Validated event fires whether you change the value in their Age text box or not. How might you stop your age increasing by 10 years every time a user leaves the Age text box?