Validation

ValidationRules

• Inherit ValidationRule and override Validate().

• Instantiate and add to the Binding.ValidationRules collection.

• Use the ValidationStep property to control when it should be applied. The possible values are ConvertedProposedValue, CommittedValue, RawProposedValue, and UpdatedValue.

IDataErrorInfo

• Used for sync validation where only single validation result suffices. Implemented by View Model. Apply ValidatesOnDataErrors or DataErrorValidationRule for binding.

INotifyDataErrorInfo [.net 4.5]

• Used for sync/async validation when more than one validation result is available. Implemented by View Model. Apply ValidatesOnNotifyDataErrors or NotifyDataErrorValidationRule for binding.

Enterprise Library 5.0 Validation Application Block

• Supports defining validation rules by using attributes, configuration, and self-validation which can also be consolidated

Windows WF

• Used for more complex sync/async business rules validations

Validation.ErrorTemplate

• Used to specify the template when control value fails validation