The CreateValidator method of the ValidatorFactory class allows you to obtain a reference to an appropriate Validator instance. This is shown in the following code example, which assumes you have resolved an instance of the ValidatorFactory class and stored it in a variable named valFactory.

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// assumes default rule set Validator<Customer> customerValidator = valFactory.CreateValidator<Customer>(); // uses named rule set Validator<Customer> goldCustomerValidator = valFactory.CreateValidator<Customer>("GoldCustomer");

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' assumes default rule set Dim customerValidator As Validator(Of Customer) = valFactory.CreateValidator(Of Customer)() ' uses named rule set Dim goldCustomerValidator As Validator(Of Customer) = valFactory.CreateValidator(Of Customer)("GoldCustomer")

The first case retrieves a reference to an instance of the Validator class that will check all Customer rules from the anonymous rule set. The second case retrieves an instance of the Validator class that will check all Customer rules in the "GoldCustomer" rule set.

By default, when you create a validator using the ValidatorFactory class, that validator will look for rules defined in configuration and in attributes in the validated classes. If you know you that only need to examine configuration or attributes for rules, you can use an alternative factory class to create validators. The other types of factory you can use are:

• ConfigurationValidatorFactory. This factory creates validators that only apply rules defined in a configuration file, or in a configuration source you provide. By default it looks for configuration in the default configuration file (App.config or Web.config). However, you can create an instance of a class that implements the IConfigurationSource interface, populate it with configuration data from another file or configuration storage media, and use this when you create this validator factory.
• AttributeValidatorFactory. This factory creates validators that only apply rules defined in Validation block attributes located in the target class, and rules defined through Self validation methods.
• ValidationAttributeValidatorFactory. This factory creates validators that only apply rules defined in .NET Data Annotations validation attributes.

You can resolve an instance of these classes through the Enterprise Library container in exactly the same way as you would the ValidatorFactory class. All of the validator factory classes expose the same interface for creating validators. The only difference is the location(s) in which they target validation rules.

After you have the reference to a Validator instance, you can validate objects. Use the Validate method to do this. This is shown in the following code example.

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Customer myCustomer = new Customer(); // Set properties of Customer object here Validator<Customer> customerValidator = valFactory.CreateValidator<Customer>(); ValidationResults results = customerValidator.Validate(myCustomer);

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Dim myCustomer As New Customer() ' Set properties of Customer object here Dim customerValidator As Validator(Of Customer) = valFactory.CreateValidator(Of Customer)() Dim results As ValidationResults = customerValidator.Validate(myCustomer)

This example creates a Customer object and invokes the Validate method of the Customer object's validator for that customer.

The CreateValidator method of the ValidatorFactory façade accepts a parameter that allows you to specify a rule set containing the validation rules. You can use this approach instead of using attributes to apply validators directly to members of a class, or in conjunction with validators defined in attributes.

For example, if you have only a single rule set named RuleSetA defined in the configuration of the application, you can apply this rule set to an object named myCustomer using the following code.

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Customer myCustomer = new Customer(); // Set properties of Customer object here Validator<Customer> customerValidator = valFactory.CreateValidator<Customer>("RuleSetA"); ValidationResults results = customerValidator.Validate(myCustomer);

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Dim myCustomer As New Customer() ' Set properties of Customer object here Dim customerValidator As Validator(Of Customer) = valFactory.CreateValidator(Of Customer)("RuleSetA") Dim results As ValidationResults = customerValidator.Validate(myCustomer)