System.IInterface.QueryInterface
Delphi
function QueryInterface(const IID: TGUID; out Obj): HResult; stdcall;
Properties
| Type | Visibility | Source | Unit | Parent |
|---|---|---|---|---|
| function | public | System.pas | System | IInterface |
Description
Returns a reference to a specified interface if the object supports that interface.
QueryInterface checks whether the object that implements the IInterface interface supports the interface specified by IID. If so, QueryInterface:
- Increments the reference count.
- Sets the
Objparameter so that it points to an instance of the specified interface. - Returns S_OK (
0) to indicate success.
If the object does not support the interface, QueryInterface returns a nonzero error code, such as E_NoInterface.