• Article

RegularExpressionAttribute Class

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Designates a regular expression to use for validation of the associated member.

Inheritance Hierarchy

System.Object
  System.Attribute
    System.ComponentModel.DataAnnotations.ValidationAttribute
      System.ComponentModel.DataAnnotations.RegularExpressionAttribute

Namespace:  System.ComponentModel.DataAnnotations
Assembly:  System.ComponentModel.DataAnnotations (in System.ComponentModel.DataAnnotations.dll)

Syntax

'Declaration
<AttributeUsageAttribute(AttributeTargets.Property Or AttributeTargets.Field Or AttributeTargets.Parameter, AllowMultiple := False)> _
Public Class RegularExpressionAttribute _
    Inherits ValidationAttribute

[AttributeUsageAttribute(AttributeTargets.Property|AttributeTargets.Field|AttributeTargets.Parameter, AllowMultiple = false)]
public class RegularExpressionAttribute : ValidationAttribute

The RegularExpressionAttribute type exposes the following members.

Constructors

  Name Description
Public method RegularExpressionAttribute Initializes a new instance of the RegularExpressionAttribute class.

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Properties

  Name Description
Public property ErrorMessage Gets or sets the non-localizable error message to display when validation fails. (Inherited from ValidationAttribute.)
Public property ErrorMessageResourceName Gets or sets the property name on the resource type that provides the localizable error message. (Inherited from ValidationAttribute.)
Public property ErrorMessageResourceType Gets or sets the resource type that provides the localizable error message. (Inherited from ValidationAttribute.)
Protected property ErrorMessageString Gets the localized or non-localized error message. (Inherited from ValidationAttribute.)
Public property Pattern Gets the regular expression to use for validation of the associated member.

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Methods

  Name Description
Public method Equals Infrastructure. Returns a value that indicates whether this instance is equal to a specified object. (Inherited from Attribute.)
Protected method Finalize Allows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.)
Public method FormatErrorMessage Applies formatting to an error message based on the data field where the error occurred. (Overrides ValidationAttribute.FormatErrorMessage(String).)
Public method GetHashCode Returns the hash code for this instance. (Inherited from Attribute.)
Public method GetType Gets the Type of the current instance. (Inherited from Object.)
Public method GetValidationResult Determines whether the specified object is valid and returns an object that includes the results of the validation check. (Inherited from ValidationAttribute.)
Protected method IsValid Determines whether the specified object is valid. (Inherited from ValidationAttribute.)
Public method Match When overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute.)
Protected method MemberwiseClone Creates a shallow copy of the current Object. (Inherited from Object.)
Public method ToString Returns a string that represents the current object. (Inherited from Object.)
Public method Validate Determines whether the specified object is valid and throws a ValidationException if the object is not valid. (Inherited from ValidationAttribute.)

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Remarks

You apply the RegularExpressionAttribute attribute to a property when you need to validate values for the property against a regular expression. The regular expression enables you to specify very precisely the format of valid values. The Pattern property contains the regular expression.

If the value of the property is nulla null reference (Nothing in Visual Basic) or an empty string (""), the value automatically passes validation for the RegularExpressionAttribute attribute. To validate that the value is not nulla null reference (Nothing in Visual Basic) or an empty string, use the RequiredAttribute attribute.

Examples

The following examples show how to apply the RegularExpressionAttribute attribute to a property that contains values for a last name.

Public Class Customer
    <Required()> _
    <RegularExpression("^[a-zA-Z''-'\s]{1,40}$", _
          ErrorMessage:="Numbers and special characters are not allowed in the last name.")> _
    Public Property LastName() As String
        'Implement Get and Set logic
    End Property
End Class

public class Customer
{
  [Required]
  [RegularExpression(@"^[a-zA-Z''-'\s]{1,40}$", 
      ErrorMessage="Numbers and special characters are not allowed in the last name.")]
  public string LastName { get; set; }
}

Version Information

Silverlight

Supported in: 5, 4, 3

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.