ComVisibleAttribute Class

Controls accessibility of an individual managed type or member, or of all types within an assembly, to COM.

System.Object
  System.Attribute
    System.Runtime.InteropServices.ComVisibleAttribute

Namespace:  System.Runtime.InteropServices
Assembly:  mscorlib (in mscorlib.dll)

[<Sealed>]
[<ComVisibleAttribute(true)>]
[<AttributeUsageAttribute(AttributeTargets.Assembly|AttributeTargets.Class|AttributeTargets.Struct|AttributeTargets.Enum|AttributeTargets.Method|AttributeTargets.Property|AttributeTargets.Field|AttributeTargets.Interface|AttributeTargets.Delegate, Inherited = false)>]
type ComVisibleAttribute =  
    class 
        inherit Attribute 
    end

The ComVisibleAttribute type exposes the following members.

  NameDescription
Public methodSupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsComVisibleAttributeInitializes a new instance of the ComVisibleAttribute class.
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  NameDescription
Public propertyTypeIdWhen implemented in a derived class, gets a unique identifier for this Attribute. (Inherited from Attribute.)
Public propertySupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsValueGets a value that indicates whether the COM type is visible.
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  NameDescription
Public methodSupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsEqualsInfrastructure. Returns a value that indicates whether this instance is equal to a specified object. (Inherited from Attribute.)
Public methodSupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsGetHashCodeReturns the hash code for this instance. (Inherited from Attribute.)
Public methodSupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsGetTypeGets 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 methodSupported by the XNA FrameworkMatchWhen overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute.)
Public methodSupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsToStringReturns 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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You can apply this attribute to assemblies, interfaces, classes, structures, delegates, enumerations, fields, methods, or properties.

The default is true, which indicates that the managed type is visible to COM. This attribute is not needed to make public managed assemblies and types visible; they are visible to COM by default. Only public types can be made visible. The attribute cannot be used to make an otherwise internal or protected type visible to COM or to make members of a nonvisible type visible.

Setting the attribute to false on the assembly hides all public types within the assembly. You can selectively make types within the assembly visible by setting the individual types to true. Setting the attribute to false on a specific type hides that type and its members. However, you cannot make members of a type visible if the type is invisible. Setting the attribute to false on a type prevents that type from being exported to a type library; classes are not registered; interfaces are never responsive to unmanaged QueryInterface calls.

Unless you explicitly set a class and its members to false, inherited classes can expose to COM base class members that are invisible in the original class. For example, if you set ClassA to false and do not apply the attribute to its members, the class and its members are invisible to COM. However, if you derive ClassB from ClassA and export ClassB to COM, ClassA members become visible base class members of ClassB.

For a detailed description of the export process, see Assembly to Type Library Conversion Summary.

The following example shows how you can control the visibility to COM of a class so that its members are invisible. By setting ComVisibleAttribute to false on MyClass (SampleClass in the Visual Basic example), and false on MyMethod and MyProperty, you can avoid inadvertently exposing the members to COM through inheritance.

No code example is currently available or this language may not be supported.

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Store apps

Supported in: Windows 8

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone 8, Silverlight 8.1

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

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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