Type Conversion Validator

Article
07/14/2010

Retired Content
This content is outdated and is no longer being maintained. It is provided as a courtesy for individuals who are still using these technologies. This page may contain URLs that were valid when originally published, but now link to sites or pages that no longer exist.
The latest Enterprise Library information can be found at the Enterprise Library site.

Class Name: TypeConversionValidator

Attribute Name: TypeConversionValidatorAttribute

Configuration tool name: Type Conversion Validator

Description

This validator checks that a string can be converted to a specific type. For example, the validator can check that "6.32" can be converted to a Double type, or that "2007-02-09" can be converted to a DateTime type.

Properties

The following table lists the Type Conversion Validator properties.

Type Conversion Validator Properties

Property	Description
Negated	This is a Boolean property. If it is set to True, it changes the validator's behavior so that it will fail if the condition is met, rather than when it is not met. The default is False.
Tag	This property is a user-supplied string. Typically, it is used to sort or categorize validation results that are in a log.
TargetType	The type to which you want to convert the string. You can either enter the type or select it with the Type Selector – System.Object dialog box.
MessageTemplate	This property is a user-supplied string. Typically, it describes the validation result and is intended for a log.
MessageTemplateResourceName	If you do not want to use the MessageTemplate property to specify a message, you can use another template by specifying it with the MessageTemplateResourceName value. If you include both a MessageTemplate value and a MessageTemplateResourceName value, the MessageTemplate value takes precedence.
MessageTemplateResourceTypeName	If you specify a MessageTemplateResourceName value then you must specify a MessageTemplateResourceTypeName value, which is the type of the template you want to use.

Message Template Tokens

If the message template contains tokens (for instance, "{0}"), the validator will replace these tokens with values when the ValidationResult is created. The tokens supported by the TypeConversionValidator are as follows:

Token	Meaning
{3}	The full name of the type to which the validator will attempt to convert.

Examples

The following examples show how to use the validator with attributes and with code.

Attributes

The following code example checks to see if the string DiscountString can be converted to type Double.

public class Product
{
   [TypeConversionValidator(typeof(double))]
   public string DiscountString
   {
      get
      {
         return discountString;
      }
   }
// ...
}

'Usage
Public Class Product
    <TypeConversionValidator(GetType(Double))> _
    ReadOnly Property DiscountString(ByVal _discountString As String)
        Get
            Return _discountString
        End Get
    End Property
' ...
End Class

Retired Content
This content is outdated and is no longer being maintained. It is provided as a courtesy for individuals who are still using these technologies. This page may contain URLs that were valid when originally published, but now link to sites or pages that no longer exist.
The latest Enterprise Library information can be found at the Enterprise Library site.

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