CustomValidationAttribute Class


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Specifies a custom validation method that is used to validate a property or class instance.

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


[AttributeUsageAttribute(AttributeTargets.Class | AttributeTargets.Method | AttributeTargets.Property | AttributeTargets.Field | AttributeTargets.Parameter, 
	AllowMultiple = true)]
public sealed class CustomValidationAttribute : ValidationAttribute

System_CAPS_pubmethodCustomValidationAttribute(Type, String)

Initializes a new instance of the CustomValidationAttribute class.


Gets or sets an error message to associate with a validation control if validation fails.(Inherited from ValidationAttribute.)


Gets or sets the error message resource name to use in order to look up the ErrorMessageResourceType property value if validation fails.(Inherited from ValidationAttribute.)


Gets or sets the resource type to use for error-message lookup if validation fails.(Inherited from ValidationAttribute.)


Gets the validation method.


Gets a value that indicates whether the attribute requires validation context.(Inherited from ValidationAttribute.)


Gets a unique identifier for this attribute.(Overrides Attribute.TypeId.)


Gets the type that performs custom validation.


This API supports the product infrastructure and is not intended to be used directly from your code. Returns a value that indicates whether this instance is equal to a specified object.(Inherited from Attribute.)


Formats a validation error message.(Overrides ValidationAttribute.FormatErrorMessage(String).)


Returns the hash code for this instance.(Inherited from Attribute.)


Gets the Type of the current instance.(Inherited from Object.)

System_CAPS_pubmethodGetValidationResult(Object, ValidationContext)

Checks whether the specified value is valid with respect to the current validation attribute.(Inherited from ValidationAttribute.)


When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class.(Inherited from Attribute.)


Determines whether the specified value of the object is valid. (Inherited from ValidationAttribute.)


When overridden in a derived class, returns a value that indicates whether this instance equals a specified object.(Inherited from Attribute.)


Returns a string that represents the current object.(Inherited from Object.)

System_CAPS_pubmethodValidate(Object, String)

Validates the specified object.(Inherited from ValidationAttribute.)

System_CAPS_pubmethodValidate(Object, ValidationContext)

Validates the specified object.(Inherited from ValidationAttribute.)

System_CAPS_pubinterfaceSystem_CAPS_privmethod_Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr)

Maps a set of names to a corresponding set of dispatch identifiers.(Inherited from Attribute.)

System_CAPS_pubinterfaceSystem_CAPS_privmethod_Attribute.GetTypeInfo(UInt32, UInt32, IntPtr)

Retrieves the type information for an object, which can be used to get the type information for an interface.(Inherited from Attribute.)


Retrieves the number of type information interfaces that an object provides (either 0 or 1).(Inherited from Attribute.)

System_CAPS_pubinterfaceSystem_CAPS_privmethod_Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr)

Provides access to properties and methods exposed by an object.(Inherited from Attribute.)

The CustomValidationAttribute attribute is used to perform custom validation when the IsValidmethod is invoked to perform validation. The IsValid method then redirects the call to the method that is identified by the Method property, which in turn performs the actual validation.

The CustomValidationAttribute attribute can be applied to types, properties, fields, methods, and method parameters. When it is applied to a property, the attribute is invoked whenever a value is assigned to that property. When it is applied to a method, the attribute is invoked whenever the program calls that method. When it is applied to a method parameter, the attribute is invoked before the method is called.

For more information about using attributes, see Extending Metadata Using Attributes.

Universal Windows Platform
Available since 8
.NET Framework
Available since 4.0
Portable Class Library
Supported in: portable .NET platforms
Available since 3.0

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

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