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id attribute

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The [id] attribute specifies a DISPID for a member function (either a property or a method, in an interface or dispinterface).

[id(id-num) [,optional-attribute-list]] return-type function-name(optional-parameter-list)

Parameters

id-num

DISPID for the function.

optional-attribute-list

Specifies a list of zero or more MIDL interface attributes.

return-type

Specifies the return type of the function.

function-name

Specifies the name of the function in the IDL file.

optional-parameter-list

Zero or more function parameters.

Remarks

Use the [id] attribute when you want to assign a standard DISPID (like DISPID_VALUE, DISPID_NEWENUM etc.) to a method or property, or when you implement your own IDispatch::Invoke instead of delegating to DispInvoke/ITypeInfo::Invoke.

If you do not use the [id] attribute on an interface, the MIDL compiler will assign a DISPID for you. However, when you specify a dispinterface by using properties and methods, you must specify a DISPID for every property and method.

The id-num is a 32-bit positive integral value. Negative IDs are reserved for use by Automation.

Examples

interface IKnown : IUnknown
{
    properties:
        [id(90), propget, 
         helpstring("A meaningful comment."] long Func1(void);

    /* Other interface statements */
}

See also

interface

dispinterface

ODL File Syntax

ODL File Example

Generating a Type Library With MIDL