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IHelpService Interface

Provides methods for showing Help topics and adding and removing Help keywords at design time.

For a list of all members of this type, see IHelpService Members.

[Visual Basic]
Public Interface IHelpService
public interface IHelpService
public __gc __interface IHelpService
public interface IHelpService


The design-time environment provides a Help system that attempts to locate relevant Help topics to display when a user presses F1. The Help system maintains a set of current context keywords that are used to identify relevant topics if Help is requested. By default, keywords are associated with selected class objects and properties of objects in the design time environment. The default keyword for a component or property is its fully qualified class or property name. Specific keywords are also associated with certain modes, such as when multiple objects are selected. If a custom Help collection is integrated with the design-time environment by configuring it for an external help provider, a documentation provider can associate a topic for a specific component class or property with a keyword consisting of the item's fully qualified type or member name.

The IHelpService can be used to invoke the help service with a specified keyword using the ShowHelpFromKeyword method, or to invoke a help topic from a specified URL using the ShowHelpFromUrl method.

The IHelpService can also be used to add or remove Help keywords at design time. Selecting a component or property at design time sets a default context keyword consisting of the fully qualified type or member name of the selection, and removes the keywords for any previously selected and no longer selected components or properties.

Because the Help system does not automatically remove custom Help keywords, you must explicitly remove a custom keyword when it no longer applies. You can monitor the events defined by the ISelectionService interface to determine when a component selection changes. Based on those events, you can add a Help context attribute for a component when it is selected and then remove the Help context attribute when the selection no longer includes the component.


Namespace: System.ComponentModel.Design

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

Assembly: System (in System.dll)

See Also

IHelpService Members | System.ComponentModel.Design Namespace | HelpKeywordType | HelpContextType