Pro WPF in C# 2010: Windows Presentation Foundation in .NET 4

19.4. Validation

Another key ingredient in any data binding scenario is validation—in other words, logic that catches incorrect values and refuses them. You can build validation directly into your controls (for example, by responding to input in the text box and refusing invalid characters), but this low-level approach limits your flexibility.

Fortunately, WPF provides a validation feature that works closely with the data binding system you've explored. Validation gives you two more options to catch invalid values:

• You can raise errors in your data object. To notify WPF of an error, simply throw an exception from a property set procedure. Ordinarily, WPF ignores any exceptions that are thrown when setting a property, but you can configure it ...