Question

I am using this code

  try
  document := (pDisp as  IWebbrowser2).Document AS IHTMLDocument2;
  Body := Document.body;
  Links := Document.links;
  for i := 0 to (Links.length-1) do
    begin
      tmp := (Links.item(i, 0) as IHTMLElement);
      tmp.onclick := TEventObject.Create(MyProcedure) as IDispatch; // THIS LINE
    end;
  except
    on E : Exception do
      ShowMessage(E.ClassName+' error raised, with message : '+E.Message);
  end;

In the DocumentComplete event of an IE web browser, it works fine but when I open a new tab I get a Microsoft Internet Explorer has encountered a problem and needs to close” error.

The line marked with // THIS LINE in the code above is the one that is causing it (I commented it and it didn’t show the error).

Here’s the rest of the code:

  TEventObject = class(TInterfacedObject, IDispatch)
  private
    FOnEvent: TProcedure;
  protected
    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;
  public
    constructor Create(const OnEvent: TProcedure);
    property OnEvent: TProcedure read FOnEvent write FOnEvent;
  end;


...........

constructor TEventObject.Create(const OnEvent: TProcedure);
begin
  inherited Create;
  FOnEvent := OnEvent;
end;

function TEventObject.GetIDsOfNames(const IID: TGUID; Names: Pointer;
  NameCount, LocaleID: Integer; DispIDs: Pointer): HResult;
begin
  Result := E_NOTIMPL;
end;

function TEventObject.GetTypeInfo(Index, LocaleID: Integer;
  out TypeInfo): HResult;
begin
  Result := E_NOTIMPL;
end;

function TEventObject.GetTypeInfoCount(out Count: Integer): HResult;
begin
  Result := E_NOTIMPL;
end;

function TEventObject.Invoke(DispID: Integer; const IID: TGUID;
  LocaleID: Integer; Flags: Word; var Params; VarResult, ExcepInfo,
  ArgErr: Pointer): HResult;
begin
  if (Dispid = DISPID_VALUE) then
  begin
    if Assigned(FOnEvent) then
      FOnEvent;
    Result := S_OK;
  end
  else Result := E_NOTIMPL;
end;

How could I make it work for tabs?

Answer 1

I found a workaround:

  URL := AnsiLowerCase(URL);
  if (URL='')  or (URL='about:blank') or (URL='about:tabs') then Exit;

The click events works ok on others pages that are not about:tabs.