The ViewModelBase derives from ModelBase, thus all information here also applies to the ViewModelBase |
The easiest way to implement validation is to override the ValidateFields and ValidateBusinessRules methods. Below is an example of an implementation of the ValidateFields method:
protected override void ValidateFields(List<IFieldValidationResult> validationResults) { if (string.IsNullOrEmpty(FirstName)) { validationResults.Add(FieldValidationResult.CreateError(FirstNameProperty, "First name is required")); } if (string.IsNullOrEmpty(LastName)) { validationResults.Add(FieldValidationResult.CreateError(LastNameProperty, "Last name is required")); } if (Gender == Gender.Unknown) { validationResults.Add(FieldValidationResult.CreateError(GenderProperty, "Gender cannot be unknown")); } } |