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HelpKeywordAttribute Class

Specifies the context keyword for a class or member. This class cannot be inherited.

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

[SerializableAttribute]
[AttributeUsageAttribute(AttributeTargets.All, AllowMultiple = false, Inherited = false)]
public sealed class HelpKeywordAttribute : Attribute

By default, the Help keyword for a class is given by the Type.FullName property value. For members, the Help keyword is given by the full name of the type that declared the property, plus the property name itself.

For example, consider the Control.Text property on the System.Windows.Forms.Button control. The class keyword is "System.Windows.Forms.Button", but the Control.Text property keyword is "System.Windows.Forms.Control.Text", because the Control.Text property is declared on the System.Windows.Forms.Control class, rather than the System.Windows.Forms.Button class itself; the System.Windows.Forms.Button class inherits the property.

By contrast, the Button.DialogResult property is declared on the System.Windows.Forms.Button class, so its keyword is "System.Windows.Forms.Button.DialogResult".

When the Help system gets the keywords, it will first look at HelpKeywordAttribute. At the class level, it will return the string specified by the HelpKeywordAttribute. This will not be used for members of the type in question, which will still reflect the declaring type's actual full name, plus the member name. This attribute supports strongly typed classes that have associated common documentation but distinct Help IDs.

The following code example shows how to override this Help system behavior by placing the attribute on the member itself. These are the keywords for the following class, called DemoComponent:

  • Class keyword: "System.ComponentModel.Component" (DemoNamespace.DemoComponent)

  • Property1 keyword: "DemoNamespace.DemoComponent.Property1" (default)

  • Property2 keyword: "SomeNamespace.SomeOtherClass.Property2" (DemoNamespace.DemoComponent.Property2)

[HelpKeywordAttribute(typeof(Component))]
public class DemoComponent : Component
{
    public string Property1
    {
        get
        {
            return "";
        }
    }

    [HelpKeywordAttribute("SomeNamespace.SomeOtherClass.Property2")]
    public string Property2
    {
        get
        {
            return "";
        }
    }
}

The following code example demonstrates using the HelpKeywordAttribute class to specify a context keyword. For a complete explanation of this code example, see How to: Apply Attributes in Windows Forms Controls.

// This control demonstrates a simple logging capability. 
[ComplexBindingProperties("DataSource", "DataMember")]
[DefaultBindingProperty("TitleText")]
[DefaultEvent("ThresholdExceeded")]
[DefaultProperty("Threshold")]
[HelpKeywordAttribute(typeof(UserControl))]
[ToolboxItem("System.Windows.Forms.Design.AutoSizeToolboxItem,System.Design")]
public class AttributesDemoControl : UserControl
{

System.Object
  System.Attribute
    System.ComponentModel.Design.HelpKeywordAttribute

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

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

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

.NET Framework

Supported in: 3.5, 3.0, 2.0

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