MetadataTypeAttribute.xml

<Type Name="MetadataTypeAttribute" FullName="System.ComponentModel.DataAnnotations.MetadataTypeAttribute">
  <TypeSignature Language="C#" Value="public sealed class MetadataTypeAttribute : Attribute" />
  <TypeSignature Language="ILAsm" Value=".class public auto ansi sealed beforefieldinit MetadataTypeAttribute extends System.Attribute" />
  <TypeSignature Language="DocId" Value="T:System.ComponentModel.DataAnnotations.MetadataTypeAttribute" />
  <TypeSignature Language="VB.NET" Value="Public NotInheritable Class MetadataTypeAttribute&#xA;Inherits Attribute" />
  <TypeSignature Language="C++ CLI" Value="public ref class MetadataTypeAttribute sealed : Attribute" />
  <TypeSignature Language="F#" Value="type MetadataTypeAttribute = class&#xA;    inherit Attribute" />
  <AssemblyInfo>
    <AssemblyName>System.ComponentModel.DataAnnotations</AssemblyName>
    <AssemblyVersion>2.0.5.0</AssemblyVersion>
    <AssemblyVersion>3.5.0.0</AssemblyVersion>
    <AssemblyVersion>4.0.0.0</AssemblyVersion>
  </AssemblyInfo>
  <AssemblyInfo>
    <AssemblyName>System.ComponentModel.Annotations</AssemblyName>
    <AssemblyVersion>4.2.0.0</AssemblyVersion>
    <AssemblyVersion>4.3.0.0</AssemblyVersion>
    <AssemblyVersion>4.3.1.0</AssemblyVersion>
    <AssemblyVersion>5.0.0.0</AssemblyVersion>
  </AssemblyInfo>
  <Base>
    <BaseTypeName>System.Attribute</BaseTypeName>
  </Base>
  <Interfaces />
  <Attributes>
    <Attribute FrameworkAlternate="net-5.0;netcore-3.0;netcore-3.1;netframework-4.0;netframework-4.5;netframework-4.5.1;netframework-4.5.2;netframework-4.6;netframework-4.6.1;netframework-4.6.2;netframework-4.7;netframework-4.7.1;netframework-4.7.2;netframework-4.8;xamarinandroid-7.1;xamarinios-10.8;xamarinmac-3.0">
      <AttributeName Language="C#">[System.AttributeUsage(System.AttributeTargets.Class, AllowMultiple=false)]</AttributeName>
      <AttributeName Language="F#">[&lt;System.AttributeUsage(System.AttributeTargets.Class, AllowMultiple=false)&gt;]</AttributeName>
    </Attribute>
    <Attribute FrameworkAlternate="netframework-3.5">
      <AttributeName Language="C#">[System.AttributeUsage(System.AttributeTargets.Class, AllowMultiple=false, Inherited=false)]</AttributeName>
      <AttributeName Language="F#">[&lt;System.AttributeUsage(System.AttributeTargets.Class, AllowMultiple=false, Inherited=false)&gt;]</AttributeName>
    </Attribute>
  </Attributes>
  <Docs>
    <summary>Specifies the metadata class to associate with a data model class.</summary>
    <remarks>
      <format type="text/markdown"><![CDATA[  
  
## Remarks  
 The <xref:System.ComponentModel.DataAnnotations.MetadataTypeAttribute> attribute enables you to associate a class with a data-model partial class. In this associated class you provide additional metadata information that is not in the data model.  
  
 For example, in the associated class you can apply the <xref:System.ComponentModel.DataAnnotations.RequiredAttribute> attribute to a data field. This enforces that a value is provided for the field even if this constraint is not required by the database schema.  
  
 You use the <xref:System.ComponentModel.DataAnnotations.MetadataTypeAttribute> attribute as follows:  
  
-   In your application, create a file in which you create the data-model partial class that you want to modify.  
  
-   Create the associated metadata class.  
  
-   Apply the <xref:System.ComponentModel.DataAnnotations.MetadataTypeAttribute> attribute to the partial entity class, specifying the associated class.  
  
 When you apply this attribute, you must adhere to the following usage constraints:  
  
-   The attribute can only be applied to a class.  

-   The attribute cannot be inherited by derived classes.  

-   The metadata class cannot add attributes to the properties of your partial class's base class.  

-   The attribute can be applied only one time.  
  
   
  
## Examples  
 The following example shows how to use the <xref:System.ComponentModel.DataAnnotations.MetadataTypeAttribute> to associate a metadata class with an entity partial class. The example applies the <xref:System.ComponentModel.DataAnnotations.RequiredAttribute> attribute to a data field to show how to provide additional information in the associated metadata class.  
  
 [!code-csharp[System.ComponentModel.DataAnnotations.MetadataTypeAttribute#1](~/samples/snippets/csharp/VS_Snippets_WebNet/System.ComponentModel.DataAnnotations.MetadataTypeAttribute/CS/Customer.cs#1)]
 [!code-vb[System.ComponentModel.DataAnnotations.MetadataTypeAttribute#1](~/samples/snippets/visualbasic/VS_Snippets_WebNet/System.ComponentModel.DataAnnotations.MetadataTypeAttribute/VB/Customer.vb#1)]  
  
 ]]></format>
    </remarks>
  </Docs>
  <Members>
    <Member MemberName=".ctor">
      <MemberSignature Language="C#" Value="public MetadataTypeAttribute (Type metadataClassType);" />
      <MemberSignature Language="ILAsm" Value=".method public hidebysig specialname rtspecialname instance void .ctor(class System.Type metadataClassType) cil managed" />
      <MemberSignature Language="DocId" Value="M:System.ComponentModel.DataAnnotations.MetadataTypeAttribute.#ctor(System.Type)" />
      <MemberSignature Language="VB.NET" Value="Public Sub New (metadataClassType As Type)" />
      <MemberSignature Language="C++ CLI" Value="public:&#xA; MetadataTypeAttribute(Type ^ metadataClassType);" />
      <MemberSignature Language="F#" Value="new System.ComponentModel.DataAnnotations.MetadataTypeAttribute : Type -&gt; System.ComponentModel.DataAnnotations.MetadataTypeAttribute" Usage="new System.ComponentModel.DataAnnotations.MetadataTypeAttribute metadataClassType" />
      <MemberType>Constructor</MemberType>
      <AssemblyInfo>
        <AssemblyName>System.ComponentModel.DataAnnotations</AssemblyName>
        <AssemblyVersion>2.0.5.0</AssemblyVersion>
        <AssemblyVersion>3.5.0.0</AssemblyVersion>
        <AssemblyVersion>4.0.0.0</AssemblyVersion>
      </AssemblyInfo>
      <AssemblyInfo>
        <AssemblyName>System.ComponentModel.Annotations</AssemblyName>
        <AssemblyVersion>4.2.0.0</AssemblyVersion>
        <AssemblyVersion>4.3.0.0</AssemblyVersion>
        <AssemblyVersion>4.3.1.0</AssemblyVersion>
        <AssemblyVersion>5.0.0.0</AssemblyVersion>
      </AssemblyInfo>
      <Attributes>
        <Attribute FrameworkAlternate="netframework-4.0">
          <AttributeName Language="C#">[System.Runtime.TargetedPatchingOptOut("Performance critical to inline this type of method across NGen image boundaries")]</AttributeName>
          <AttributeName Language="F#">[&lt;System.Runtime.TargetedPatchingOptOut("Performance critical to inline this type of method across NGen image boundaries")&gt;]</AttributeName>
        </Attribute>
      </Attributes>
      <Parameters>
        <Parameter Name="metadataClassType" Type="System.Type" />
      </Parameters>
      <Docs>
        <param name="metadataClassType">The metadata class to reference.</param>
        <summary>Initializes a new instance of the <see cref="T:System.ComponentModel.DataAnnotations.MetadataTypeAttribute" /> class.</summary>
        <remarks>
          <format type="text/markdown"><![CDATA[  
  
## Examples  
 The following example shows how to use the <xref:System.ComponentModel.DataAnnotations.MetadataTypeAttribute> to associate a metadata class with an entity partial class.  
  
 [!code-csharp[System.ComponentModel.DataAnnotations.MetadataTypeAttribute#2](~/samples/snippets/csharp/VS_Snippets_WebNet/System.ComponentModel.DataAnnotations.MetadataTypeAttribute/CS/Customer.cs#2)]
 [!code-vb[System.ComponentModel.DataAnnotations.MetadataTypeAttribute#2](~/samples/snippets/visualbasic/VS_Snippets_WebNet/System.ComponentModel.DataAnnotations.MetadataTypeAttribute/VB/Customer.vb#2)]  
  
 ]]></format>
        </remarks>
        <exception cref="T:System.ArgumentNullException">
          <paramref name="metadataClassType" /> is <see langword="null" />.</exception>
      </Docs>
    </Member>
    <Member MemberName="MetadataClassType">
      <MemberSignature Language="C#" Value="public Type MetadataClassType { get; }" />
      <MemberSignature Language="ILAsm" Value=".property instance class System.Type MetadataClassType" />
      <MemberSignature Language="DocId" Value="P:System.ComponentModel.DataAnnotations.MetadataTypeAttribute.MetadataClassType" />
      <MemberSignature Language="VB.NET" Value="Public ReadOnly Property MetadataClassType As Type" />
      <MemberSignature Language="C++ CLI" Value="public:&#xA; property Type ^ MetadataClassType { Type ^ get(); };" />
      <MemberSignature Language="F#" Value="member this.MetadataClassType : Type" Usage="System.ComponentModel.DataAnnotations.MetadataTypeAttribute.MetadataClassType" />
      <MemberType>Property</MemberType>
      <AssemblyInfo>
        <AssemblyName>System.ComponentModel.DataAnnotations</AssemblyName>
        <AssemblyVersion>2.0.5.0</AssemblyVersion>
        <AssemblyVersion>3.5.0.0</AssemblyVersion>
        <AssemblyVersion>4.0.0.0</AssemblyVersion>
      </AssemblyInfo>
      <AssemblyInfo>
        <AssemblyName>System.ComponentModel.Annotations</AssemblyName>
        <AssemblyVersion>4.2.0.0</AssemblyVersion>
        <AssemblyVersion>4.3.0.0</AssemblyVersion>
        <AssemblyVersion>4.3.1.0</AssemblyVersion>
        <AssemblyVersion>5.0.0.0</AssemblyVersion>
      </AssemblyInfo>
      <ReturnValue>
        <ReturnType>System.Type</ReturnType>
      </ReturnValue>
      <Docs>
        <summary>Gets the metadata class that is associated with a data-model partial class.</summary>
        <value>The type value that represents the metadata class.</value>
        <remarks>To be added.</remarks>
      </Docs>
    </Member>
  </Members>
</Type>