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AttributeProviderAttribute Class

Enables attribute redirection. This class cannot be inherited.

System.Object
  System.Attribute
    System.ComponentModel.AttributeProviderAttribute

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

[AttributeUsageAttribute(AttributeTargets.Property)]
public class AttributeProviderAttribute : Attribute

The AttributeProviderAttribute type exposes the following members.

  NameDescription
Public methodAttributeProviderAttribute(String)Initializes a new instance of the AttributeProviderAttribute class with the given type name.
Public methodAttributeProviderAttribute(Type)Initializes a new instance of the AttributeProviderAttribute class with the given type.
Public methodAttributeProviderAttribute(String, String)Initializes a new instance of the AttributeProviderAttribute class with the given type name and property name.
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  NameDescription
Public propertyPropertyNameGets the name of the property for which attributes will be retrieved.
Public propertyTypeIdWhen implemented in a derived class, gets a unique identifier for this Attribute. (Inherited from Attribute.)
Public propertyTypeNameGets the assembly qualified type name passed into the constructor.
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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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There are a few cases in the .NET Framework object model where a property is purposely typed to be vague. For example, the DataGridView.DataSource property is typed as object. The reason for this is that this property can accept several types of input. Unfortunately, this provides no common place to add metadata to describe the characteristics of the property. Each DataSource property throughout the .NET Framework needs to have identical metadata for type converters, UI type editors, and other services that require metadata. The AttributeProviderAttribute remedies this situation.

Once this attribute is placed on a property, the rules for obtaining attributes for the property descriptor's MemberDescriptor.Attributes collection differ. Typically, the property descriptor gathers local attributes, and then merges these with attributes from the property type. In this case, the attributes are taken from the type returned from the AttributeProviderAttribute, not from the actual property type. This attribute is used on DataGridView.DataSource to point the DataGridView.DataSource object's specific type to IListSource, and the appropriate metadata is placed on IListSource to enable data binding. In so doing, external parties can easily add metadata to all data sources.

Attributes obtained from a type declared in the AttributeProviderAttribute have a priority in between the attributes of the property’s type and the attributes on the property. The following list, in priority order, shows the full set of available merged attributes:

  • Property Attributes

  • Attribute Provider Attributes

  • Property Type Attributes

The following code example demonstrates using AttributeProviderAttribute to mark a DataSource property with a specific type of IListSource. For a full code listing, see How to: Apply Attributes in Windows Forms Controls.


[Category("Data")]
[Description("Indicates the source of data for the control.")]
[RefreshProperties(RefreshProperties.Repaint)]
[AttributeProvider(typeof(IListSource))]
public object DataSource
{
    get
    {
        return this.dataGridView1.DataSource;
    }

    set
    {
        this.dataGridView1.DataSource = value;
    }
}


.NET Framework

Supported in: 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, 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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