GlobalObject Class

Article
02/04/2013

Provides the base class for types whose instances are accessible for each project.

Inheritance Hierarchy

System.Object
  System.MarshalByRefObject
    Microsoft.VisualStudio.Shell.Design.GlobalType
      Microsoft.VisualStudio.Shell.Design.GlobalObject

Namespace: Microsoft.VisualStudio.Shell.Design
Assembly: Microsoft.VisualStudio.Shell.Design (in Microsoft.VisualStudio.Shell.Design.dll)

Syntax

'Declaration
Public MustInherit Class GlobalObject _
    Inherits GlobalType

public abstract class GlobalObject : GlobalType

public ref class GlobalObject abstract : public GlobalType

[<AbstractClass>]
type GlobalObject =  
    class
        inherit GlobalType
    end

public abstract class GlobalObject extends GlobalType

The GlobalObject type exposes the following members.

Constructors

	Name	Description
	GlobalObject	Initializes a new instance of the GlobalObject class.

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Properties

	Name	Description
	Instance	Gets an on-demand created instance of the global object.
	Name	Gets the recommended name of the global object.
	ObjectType	Gets the checked type of the GlobalType. (Inherited from GlobalType.)

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Methods

	Name	Description
	ClearInstance	Clears the Instance property.
	ClearObjectType	Clears the ObjectType property. (Inherited from GlobalType.)
	CreateInstance	Creates a cached instance of the global object.
	CreateObjRef	Creates an object that contains all the relevant information required to generate a proxy used to communicate with a remote object. (Inherited from MarshalByRefObject.)
	Equals	Checks if the specified object is equal to the current global object. (Overrides GlobalType.Equals(Object).)
	Finalize	Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
	GetHashCode	Returns the hash code for the current global object. (Overrides GlobalType.GetHashCode().)
	GetLifetimeService	Retrieves the current lifetime service object that controls the lifetime policy for this instance. (Inherited from MarshalByRefObject.)
	GetObjectType	Returns the type of this global type. (Inherited from GlobalType.)
	GetSerializer	Returns the checked serializer of the specified type for the global object.
	GetSerializerCore	Returns a serializer of the specified type for the global object.
	GetType	Gets the Type of the current instance. (Inherited from Object.)
	InitializeLifetimeService	Obtains a lifetime service object to control the lifetime policy for this instance. (Inherited from MarshalByRefObject.)
	MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object.)
	MemberwiseClone(Boolean)	Creates a shallow copy of the current MarshalByRefObject object. (Inherited from MarshalByRefObject.)
	OnChanged	Raises the Changed event. (Inherited from GlobalType.)
	OnChanging	Raises the Changing event. (Inherited from GlobalType.)
	OnCreated	Raises the Created event.
	OnRemoved	Raises the Removed event. (Inherited from GlobalType.)
	OnRemoving	Raises the Removing event. (Inherited from GlobalType.)
	PerformChange	Reinitializes the global object and notifies users to changes to its state or shape. (Overrides GlobalType.PerformChange().)
	PerformRemove	Clears the global object and notifies users of its removal. (Overrides GlobalType.PerformRemove().)
	ToString	Returns a string that represents the current object. (Inherited from Object.)

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Events

	Name	Description
	Changed	Occurs after the current global type is modified. (Inherited from GlobalType.)
	Changing	Occurs before the current global type is modified. (Inherited from GlobalType.)
	Created	Occurs when an instance of the global object is created.
	Removed	Occurs after the current global type is removed from use. (Inherited from GlobalType.)
	Removing	Occurs before the current global type is removed from use. (Inherited from GlobalType.)

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Remarks

A global object is an object that is accessible over an entire project, rather than just within a single application or a single form. For example, project-wide resource files provided in a Windows Forms application are global objects. Global objects have the following characteristics:

They are global to a project and are therefore single-instanced.
They are accessed by means of a static method or property on a class.
They are commonly custom types that are automatically generated by the project system.
They often change as a result of actions in other files within the project.
They can be marshaled from the default domain across other application domains because the GlobalObject class is derived from System.MarshalByRefObject. Marshaling requires that the global object instance be serializable.

While you perceive global objects as global, and this is also how they behave at runtime, at design time they are actually instanced for each designer. This enables the designers to maintain their own copies and remain isolated. The GlobalObjectService interacts with instances of GlobalObject in order to create these global object instances for each designer.

Global objects are not created directly; rather, a call to the GetGlobalObjects method of the GlobalObjectService class initiates a process that creates the desired global object instance.

GlobalObject also supports the creation of global types. A global type is a standard instanced object, but the type for this object comes from a project in the solution or from generated code. For more information about global types, see the base class GlobalType.

In the first version of the .NET Framework, types and instances were exposed through the existing project references system. Because this system uses real, compiled types it suffered from slower performance, duplicated data types, and the need to restart the designer environment when types were changed. Global types and virtual types were introduced in the second version of the Managed Package Framework to solve these problems. A virtual type enables the dynamic creation of a type and instances of that type based on an existing base class. Virtual types mimic ordinary compiled types when examined by the reflection application programming interface (API), but do not have a true class implementation. For more information about virtual types, see the VirtualTypeBuilder class.

Examples

The following code example shows some global objects.

DataSet cust = Customers.DefaultInstance;
String error = MyAppResources.ErrorString;
Bitmap logo = MyAppResources.ProductLogo;

The following code example shows some global types.

DataSet cust = new CustomerDataSet();

Thread Safety

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