IOleControl interface

Lets a container ask an OLE control for its keyboard mnemonics, and tell the control about changes to the container’s ambient properties and about frozen events.

IOleControl has the interface identifier B196B288-BAB4-101A-B69C-00AA00341D07 and extends stdole.IUnknown. It is declared [OleAutomation(False)]. Microsoft Learn describes the Windows interface: IOleControl.

The declaration is complete: it has all four methods of the Windows interface. GetControlInfo and OnMnemonic are marked [PreserveSig], so a class cannot implement this interface; it is for calling. IOleControlVB declares the same two methods in a form a class can implement. OnAmbientPropertyChange and FreezeEvents hide the HRESULT: a failure code raises a run-time error.

Methods

GetControlInfo

[PreserveSig]
Function GetControlInfo(ByRef pCI As OLECONTROLINFO) As Long

Fills pCI with the control’s keyboard mnemonics and keyboard behavior. The caller sets the structure’s cb field to its size before the call. The result is the raw HRESULT; a control that has no mnemonics returns E_NOTIMPL (&H80004001).

OnMnemonic

[PreserveSig]
Function OnMnemonic(ByRef pMsg As OLEACCELMSG) As Long

Tells the control that the user pressed one of the mnemonic keys it listed in GetControlInfo. pMsg holds the keystroke message. The result is the raw HRESULT.

OnAmbientPropertyChange

Sub OnAmbientPropertyChange(ByVal DispID As Long)

Tells the control that an ambient property of the container changed. DispID is the dispatch identifier of the property, or -1 (DISPID_UNKNOWN) when more than one property changed.

FreezeEvents

Sub FreezeEvents(ByVal bFreeze As Long)

Tells the control to stop firing events, when bFreeze is not 0, or to resume, when it is 0.