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DisplayColumnAttribute Class

Specifies the column that is displayed in the referred table as a foreign-key column.

System.Object
  System.Attribute
    System.ComponentModel.DataAnnotations.DisplayColumnAttribute

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

[<AttributeUsageAttribute(AttributeTargets.Class, Inherited = true, AllowMultiple = false)>]
type DisplayColumnAttribute =  
    class
        inherit Attribute
    end

The DisplayColumnAttribute type exposes the following members.

  NameDescription
Public methodDisplayColumnAttribute(String)Initializes a new instance of the DisplayColumnAttribute class by using the specified column.
Public methodDisplayColumnAttribute(String, String)Initializes a new instance of the DisplayColumnAttribute class by using the specified display and sort columns.
Public methodDisplayColumnAttribute(String, String, Boolean)Initializes a new instance of the DisplayColumnAttribute class by using the specified display column, and the specified sort column and sort order.
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  NameDescription
Public propertyDisplayColumnGets the name of the column to use as the display field.
Public propertySortColumnGets the name of the column to use for sorting.
Public propertySortDescendingGets a value that indicates whether to sort in descending or ascending order.
Public propertyTypeIdWhen implemented in a derived class, gets a unique identifier for this Attribute. (Inherited from Attribute.)
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  NameDescription
Public methodEqualsInfrastructure. Returns a value that indicates whether this instance is equal to a specified object. (Inherited from Attribute.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodGetHashCodeReturns the hash code for this instance. (Inherited from Attribute.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Public methodIsDefaultAttributeWhen overridden in a derived class, indicates whether the value of this instance is the default value for the derived class. (Inherited from Attribute.)
Public methodMatchWhen overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)
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  NameDescription
Explicit interface implemetationPrivate method_Attribute.GetIDsOfNamesMaps a set of names to a corresponding set of dispatch identifiers. (Inherited from Attribute.)
Explicit interface implemetationPrivate method_Attribute.GetTypeInfoRetrieves the type information for an object, which can be used to get the type information for an interface. (Inherited from Attribute.)
Explicit interface implemetationPrivate method_Attribute.GetTypeInfoCountRetrieves the number of type information interfaces that an object provides (either 0 or 1). (Inherited from Attribute.)
Explicit interface implemetationPrivate method_Attribute.InvokeProvides access to properties and methods exposed by an object. (Inherited from Attribute.)
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When a column in a table contains a foreign key, Dynamic Data infers the display value for that column from the referenced table. By default, the first column of the referenced table whose type is string (or text) is used. The DisplayColumnAttribute attribute enables you to change this default behavior and to specify a different parent table column to use as the column for the foreign key field.

When you apply this attribute, you must adhere to the following usage constraints:

  • The attribute can only be applied to a class.

  • The attribute can be inherited by derived classes.

  • The attribute can be applied only one time.

The following example shows how to use the DisplayColumnAttribute attribute. The example performs the following tasks:

  • Implements metadata partial classes for the Address and Customer tables, which are parent tables for the CustomerAddress table.

  • Applies the DisplayColumnAttribute attribute to the Address metadata partial class to specify the following:

    • The City column from the Address table (the parent table) is displayed as the foreign-key column in the CustomerAddress child table.

    • The PostalCode column from the Address table (the parent table) is used for sorting the Address selection box in the CustomerAddress child table.

    • The sort order is set to ascending.

The example applies the DisplayColumnAttribute attribute to the Customer metadata partial class to specify that the LastName column in displayed as the foreign-key column for the CustomerAddress table.

No code example is currently available or this language may not be supported.

To compile the example, you need the following:

  • Visual Studio 2008 Service Pack 1 or Visual Developer 2008 Express Edition Service Pack 1.

  • The AdventureWorksLT sample database. For information about how to download and install the SQL Server sample database, see Microsoft SQL Server Product Samples: Database on the CodePlex site. Make sure that you install the correct version of the sample database for the version of SQL Server that you are running (SQL Server 2005 or SQL Server 2008).

  • A dynamic data-driven Web site. This enables you to create a data context for the database and to create the class that contains the data field to customize. For more information, see Walkthrough: Creating a New Dynamic Data Web Site using Scaffolding.

.NET Framework

Supported in: 4, 3.5 SP1

.NET Framework Client Profile

Supported in: 4

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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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