HelpKeywordAttribute Class
 
System_CAPS_noteNote

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

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

SystemObject
   SystemAttribute
    System.ComponentModel.DesignHelpKeywordAttribute

[SerializableAttribute]
[AttributeUsageAttribute(AttributeTargets.All, AllowMultiple = false, 
	Inherited = false)]
public sealed class HelpKeywordAttribute : Attribute
[SerializableAttribute]
[AttributeUsageAttribute(AttributeTargets::All, AllowMultiple = false, 
	Inherited = false)]
public ref class HelpKeywordAttribute sealed : Attribute
[<Sealed>]
[<SerializableAttribute>]
[<AttributeUsageAttribute(AttributeTargets.All, AllowMultiple = false,
    Inherited = false)>]
type HelpKeywordAttribute = 
    class
        inherit Attribute
    end
<SerializableAttribute>
<AttributeUsageAttribute(AttributeTargets.All, AllowMultiple := False,
	Inherited := False)>
Public NotInheritable Class HelpKeywordAttribute
	Inherits Attribute
NameDescription
System_CAPS_pubmethod HelpKeywordAttribute

Initializes a new instance of the HelpKeywordAttribute class.

System_CAPS_pubmethod HelpKeywordAttribute

Initializes a new instance of the HelpKeywordAttribute class.

System_CAPS_pubmethod HelpKeywordAttribute

Initializes a new instance of the HelpKeywordAttribute class from the given type.

NameDescription
System_CAPS_pubproperty

Gets the Help keyword supplied by this attribute.

System_CAPS_pubproperty

When implemented in a derived class, gets a unique identifier for this Attribute.(Inherited from Attribute.)

NameDescription
System_CAPS_pubmethod Equals

Determines whether two HelpKeywordAttribute instances are equal.(Overrides AttributeEquals.)

System_CAPS_pubmethod GetHashCode

Returns the hash code for this instance.(Overrides AttributeGetHashCode.)

System_CAPS_pubmethod GetType

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

System_CAPS_pubmethod IsDefaultAttribute

Determines whether the Help keyword is null.(Overrides AttributeIsDefaultAttribute.)

System_CAPS_pubmethod Match

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

System_CAPS_pubmethod ToString

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

NameDescription
System_CAPS_pubfield System_CAPS_static Default

Represents the default value for HelpKeywordAttribute. This field is read-only.

NameDescription
System_CAPS_pubinterface System_CAPS_privmethod _AttributeGetIDsOfNames

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

System_CAPS_pubinterface System_CAPS_privmethod _AttributeGetTypeInfo

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

System_CAPS_pubinterface System_CAPS_privmethod _AttributeGetTypeInfoCount

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

System_CAPS_pubinterface System_CAPS_privmethod _AttributeInvoke

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

By default, the Help keyword for a class is given by the 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 property on the System.Windows.FormsButton control. The class keyword is "System.Windows.Forms.Button", but the property keyword is "System.Windows.Forms.Control.Text", because the property is declared on the System.Windows.FormsControl class, rather than the System.Windows.FormsButton class itself; the System.Windows.FormsButton class inherits the property.

By contrast, the property is declared on the System.Windows.FormsButton 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
{
' This control demonstrates a simple logging capability. 
<ComplexBindingProperties("DataSource", "DataMember"), _
DefaultBindingProperty("TitleText"), _
DefaultEvent("ThresholdExceeded"), _
DefaultProperty("Threshold"), _
HelpKeywordAttribute(GetType(UserControl)), _
ToolboxItem("System.Windows.Forms.Design.AutoSizeToolboxItem,System.Design")> _
Public Class AttributesDemoControl
    Inherits UserControl
.NET Framework
Available since 2.0

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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