一个IE　COM接口的例子

需要建立一个COM对象，实现IDispatch, IObjectWithSite接口，如下
TIEHelper = class(TComObject, IDispatch, IObjectWithSite)
public
function GetTypeInfoCount(out Count: Integer): HResult; stdcall;
function GetTypeInfo(Index, LocaleID: Integer; out TypeInfo): HResult; stdcall;
function GetIDsOfNames(const IID: TGUID; Names: Pointer;
NameCount, LocaleID: Integer; DispIDs: Pointer): HResult; stdcall;
function Invoke(DispID: Integer; const IID: TGUID; LocaleID: Integer;
Flags: Word; var Params; VarResult, ExcepInfo, ArgErr: Pointer): HResult; stdcall;
function SetSite(const pUnkSite: IUnknown): HResult; stdcall;
function GetSite(const riid: TIID; out site: IUnknown): HResult; stdcall;
private
IE: IWebbrowser2;
Cookie: Integer;
end;
在SetSite方法中处理与IE的连接：
function TIEHelper.SetSite(const pUnkSite: IUnknown): HResult;
var
cmdTarget: IOleCommandTarget;
Sp: IServiceProvider;
CPC: IConnectionPointContainer;
CP: ICOnnectionPoint;
begin
if Assigned(pUnkSite) then begin
cmdTarget := pUnkSite as IOleCommandTarget;
Sp := CmdTarget as IServiceProvider;
if Assigned(Sp)then
Sp.QueryService(IWebbrowserApp, IWebbrowser2, IE);
if Assigned(IE) then begin
IE.QueryInterface(IConnectionPointContainer, CPC);
CPC.FindConnectionPoint(DWEBbrowserEvents2, CP);
CP.Advise(Self, Cookie)
end;
end;
Result := S_OK;
end;
然后当IE事件引发后，会调用服务器的Invoke事件，在事件中判断DispID并执行
相应的处理：
function TIEHelper.Invoke(DispID: Integer; const IID: TGUID; LocaleID: Integer;
Flags: Word; var Params; VarResult, ExcepInfo, ArgErr: Pointer): HResult;
type
POleVariant = ^OleVariant;
var
dps: TDispParams absolute Params;
bHasParams: boolean;
pDispIds: PDispIdList;
iDispIdsSize: integer;
begin
Result := DISP_E_MEMBERNOTFOUND;
pDispIds := nil;
iDispIdsSize := 0;
bHasParams := (dps.cArgs > 0);
if (bHasParams) then
begin
iDispIdsSize := dps.cArgs * SizeOf(TDispId);
GetMem(pDispIds, iDispIdsSize);
end;
try
if (bHasParams) then BuildPositionalDispIds(pDispIds, dps);
case DispId of
102:
begin
DoStatusTextChange(dps.rgvarg^[pDispIds^[0]].bstrval);
Result := S_OK;
end;
108:
begin
DoProgressChange(dps.rgvarg^[pDispIds^[0]].lval, dps.rgvarg^[pDispIds^[1]].lval);
Result := S_OK;
end;
最后，需要在注册时在注册表中添加附加信息以便IE调用：
type
TIEHelperFactory = class(TComObjectFactory)
private
procedure AddKeys;
procedure RemoveKeys;
public
procedure UpdateRegistry(Register: Boolean); override;
end;
procedure TIEHelperFactory.AddKeys;
var S: string;
begin
S := GUIDToString(CLASS_IEHelper);
with TRegistry.Create do
try
RootKey := HKEY_LOCAL_MACHINE;
if OpenKey('SoftwareHelper Objects + S, TRUE)
then CloseKey;
finally
free;
end;
end;
procedure TIEHelperFactory.RemoveKeys;
var S: string;
begin
S := GUIDToString(CLASS_IEHelper);
with TRegistry.Create do
try
RootKey := HKEY_LOCAL_MACHINE;
DeleteKey('SoftwareHelper Objects + S);
finally
free;
end;
end;
procedure TIEHelperFactory.UpdateRegistry(Register: Boolean);
begin
inherited UpdateRegistry(Register);
if Register then AddKeys else RemoveKeys;
end;
initialization
TIEHelperFactory.Create(ComServer, TIEHelper, Class_IEHelper,
'IEHelper', '', ciMultiInstance, tmApartment);
end.