ComObjQuery() [v1.0.96.00+]

Queries a COM object for an interface or service.

InterfacePointer := ComObjQuery(ComObject, [SID,] IID)



A COM wrapper object or raw interface pointer.


An interface identifier (GUID) in the form "{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}".


A service identifier in the same form as IID. When omitting this parameter, also omit the comma.

General Remarks

In its two-parameter mode, this function is equivalent to IUnknown::QueryInterface. When SID and IID are both specified, it internally queries for the IServiceProvider interface, then calls IServiceProvider::QueryService. In either case, the return value is either zero or a pointer to the requested interface. Generally this pointer must be released when the script is finished with it.


ObjRelease, ComObjCreate, ComObjGet, ComObjActive, ComObjError


; Example: Determine the class name of an object.

obj := ComObjCreate("Scripting.Dictionary")

MsgBox % "Interface name: " ComObjType(obj, "name")

IID_IProvideClassInfo := "{B196B283-BAB4-101A-B69C-00AA00341D07}"

; Request a pointer to the object's IProvideClassInfo interface.
if !(pci := ComObjQuery(obj, IID_IProvideClassInfo))
    MsgBox IProvideClassInfo interface not supported.

; Call GetClassInfo to retrieve a pointer to the ITypeInfo interface.
DllCall(vtable(pci, 3), "ptr", pci, "ptr*", ti)

; Call GetDocumentation to get the object's full type name.
DllCall(vtable(ti, 12), "ptr", ti, "int", -1, "ptr*", name, "ptr", 0, "ptr", 0, "ptr", 0)

; Convert the BSTR pointer to a usable string.
name := StrGet(name, "UTF-16")

; Release raw interface pointers.

; Display the type name!
MsgBox % "Class name: " name

vtable(ptr, n) {
    ; NumGet(ptr+0) returns the address of the object's virtual function
    ; table (vtable for short). The remainder of the expression retrieves
    ; the address of the nth function's address from the vtable.
    return NumGet(NumGet(ptr+0), n*A_PtrSize)
; Example: Automate an existing Internet Explorer window.

sURL := ""
if webBrowser := GetWebBrowser()

    ; Get a raw pointer to the document object of the top-most IE window.
    static msg := DllCall("RegisterWindowMessage", "str", "WM_HTML_GETOBJECT")
    SendMessage msg, 0, 0, Internet Explorer_Server1, ahk_class IEFrame
    if ErrorLevel = FAIL
        return  ; IE not found.
    lResult := ErrorLevel
    DllCall("oleacc\ObjectFromLresult", "ptr", lResult
        , "ptr", GUID(IID_IHTMLDocument2,"{332C4425-26CB-11D0-B483-00C04FD90119}")
        , "ptr", 0, "ptr*", pdoc)
    ; Query for the WebBrowserApp service. In this particular case,
    ; the SID and IID are the same, but it isn't always this way.
    static IID_IWebBrowserApp := "{0002DF05-0000-0000-C000-000000000046}"
    static SID_SWebBrowserApp := IID_IWebBrowserApp
    pweb := ComObjQuery(pdoc, SID_SWebBrowserApp, IID_IWebBrowserApp)
    ; Release the document object pointer.
    ; Return the WebBrowser object, wrapped for usability:
    static VT_DISPATCH := 9, F_OWNVALUE := 1
    return ComObject(VT_DISPATCH, pweb, F_OWNVALUE)

GUID(ByRef GUID, sGUID) ; Converts a string to a binary GUID and returns its address.
    VarSetCapacity(GUID, 16, 0)
    return DllCall("ole32\CLSIDFromString", "wstr", sGUID, "ptr", &GUID) >= 0 ? &GUID : ""