Type Library Attributes

The following keywords specify type library information within the context of a library statement in an IDL file.

Attribute	Usage
aggregatable	Defines the coclass as supporting objects that can directly expose another object's interface pointer.
appobject	Identifies the coclass as an application object, which is associated with a full EXE application.
bindable	Indicates that the property supports data binding. This allows the client to be notified whenever a property has changed value.
coclass	Provides a listing of the supported interfaces for a component object.
control	Identifies a coclass or library as a COM control, from which a container site will derive additional type libraries or component object classes.
custom	Defines a custom attribute (one not defined in MIDL).
default	Indicates that the interface or dispinterface, defined within a coclass, represents the default interface.
defaultbind	Indicates the single, bindable property that best represents the object.
defaultcollelem	Flags the property as an accessor function for an element of the default collection. Used for Microsoft Visual Basic code optimization.
defaultvalue	Allows specification of a default value for a typed optional parameter.
defaultvtable	Allows an object to have two different source interfaces.
dispinterface	Defines a set of properties and methods on which you can call IDispatch::Invoke.
displaybind	Indicates a property that should be displayed to the user as bindable.
dllname(str)	Defines the name of the DLL that contains the entry points for a module.
dual	Identifies an interface that exposes properties and methods both through IDispatch and directly through the Vtable.
entry	Specifies an exported function or constant in a module by identifying the entry point in the DLL.
helpcontext	Specifies a context identifier that lets the user view information about this element in the Help file.
helpfile	Sets the name of the Help file for a type library.
helpstring	Specifies a character string that is used to describe the element to which it applies.
helpstringdll	Sets the name of the DLL to use to perform the document string lookup.
hidden	Indicates that the item exists but should not be displayed in a user-oriented browser.
id	Specifies a DISPID for a member function (either a property or a method, in an interface or dispinterface).
immediatebind	Indicates that the database will be notified immediately of all changes to a property of a data-bound object.
lcid	When applied to the library statement, along with a localeID argument, identifies the locale for a type library or for a function argument and lets you use international characters inside the library block. Within a library statement, from the point where the lcid attribute is used, MIDL will accept input localized according to the specified locale.
library	Instructs the MIDL compiler to generate type library information for the interfaces and classes referenced inside the statement.
licensed	Indicates that the coclass to which it applies is licensed, and instances must be created using IClassFactory2.
nonbrowsable	Indicates that the property appears in an object browser (which does not show property values), but does not appear in a properties browser (which does show property values).
noncreatable	Prevents a client from using the default class factory to create instances of an object interface.
nonextensible	Specifies that the IDispatch implementation includes only the properties and methods listed in the interface description and cannot be extended with additional members at runtime.
oleautomation	Indicates that an interface is compatible with automation.
optional	Specifies an optional parameter for a member function.
propget	Specifies a property accessor function.
propput	Specifies a property-setting function.
propputref	Specifies a property-setting function that uses a reference instead of a value.
public	Ensures that an alias declared with typedef becomes part of the type library.
readonly	Prohibits assigning a new value to a variable.
requestedit	Indicates that the property supports the OnRequestEdit notification.
restricted	Specifies that a library, or member of a module, interface, or dispinterface cannot be called arbitrarily.
retval	Designates the parameter that receives the return value of the member.
source	Indicates that a member of a coclass, property, or method is a source of events.
string	Indicates that the one-dimensional char, wchar_t, byte (or equivalent) array or the pointer to such an array must be treated as a string.
uidefault	Indicates that the type information member is the default member for display in the user interface.
usesgetlasterror	Specifies that a module entry point uses SetLastError to return error codes and that a caller can then call GetLastError to retrieve the error code if there is an error on entering a function.
uuid	Designates a unique identifier for a type library, coclass, or interface.
vararg	Specifies that the function takes a variable number of arguments.
version	Identifies a particular version of a type library.

 

Related topics

ODL File Syntax

ODL File Example

Generating a Type Library With MIDL