Marshal.GetStartComSlot(Type) Method

Definition

Namespace:

System.Runtime.InteropServices

Assemblies:

netstandard.dll, System.Runtime.InteropServices.dll

Source:

Marshal.NoCom.cs

Gets the first slot in the virtual function table (v-table or VTBL) that contains user-defined methods.

C#

[System.Runtime.Versioning.SupportedOSPlatform("windows")]
public static int GetStartComSlot(Type t);

Parameters

t

Type

A type that represents an interface or a class.

Returns

Int32

The first VTBL slot that contains user-defined methods. The first slot is 3 if the interface is based on IUnknown, and 7 if the interface is based on IDispatch.

Attributes

SupportedOSPlatformAttribute

Exceptions

ArgumentException

t is not visible from COM.

Remarks

This method returns the zero-based v-table number for an interface or a class. When used on a class, the slot number that is returned refers to the class interface for the class. If the class interface is auto-dispatch, this method always returns -1 to indicate that the dispatch-only interface does not expose a v-table to managed clients. You can use GetStartComSlot and Marshal.GetEndComSlot in conjunction with Marshal.GetMethodInfoForComSlot to pass slots within a specified range. For additional information, see Introducing the class interface.

Applies to

See also

• GetEndComSlot(Type)
• GetMethodInfoForComSlot(Type, Int32, ComMemberType)