Du greifst auf die Controls von WebControl1 zu bevor diese existieren. Probier doch mal folgendes:
Delphi-Quellcode:
procedure TForm1.WebBrowser1DownloadComplete(Sender: TObject);
begin
if webbrowser1.readystate >= 3 then
begin
pagecontrol1.ActivePage:=tabsheet1;
ProgressBar1.Position := 100;
end;
end;
procedure TForm1.WebBrowser1ProgressChange(ASender: TObject; Progress,
ProgressMax: Integer);
begin
if webbrowser1.ReadyState = 0 then begin
progressbar1.Position:=20;
end
else if webbrowser1.ReadyState = 1 then begin
progressbar1.Position:=35;
end
else if webbrowser1.ReadyState = 2 then begin
progressbar1.Position:=60;
end
else if webbrowser1.ReadyState = 3 then begin
progressbar1.Position:=90;
end
end;