Question

I started using Overbyte components , used to use Indy but blocking issue made me look for something else , so I found ICS , but in this example code:

HTTPAsync

It creates new HTTPCli component for every link inside listbox , but when I change code a bit:

procedure THttpAsyForm.HttpCli1DocData(Sender: TObject; Buffer: Pointer;
  Len: Integer);
var
    AHttpCli : THttpCli;
begin
    if not DataCheckBox.Checked then
        Exit;

    AHttpCli := Sender as THttpCli;
    { Display a message stating that data is available }
    DisplayMemo.Lines.Add('Item ' + IntToStr(AHttpCli.Tag) + ' Data');

    { We could display the data, but it use a huge space in the display }
     DisplayMemo.Lines.Add(StrPas(Buffer));
  if something then   <--- CODE I ADDED       
  ListBox1.items.add(AHttpCli.URL); <--- CODE I ADDED 

    { We could also store the data somewhere (with the help of OnDocBegin }
    { and OnDocEnd events. Or using the RcvdStream property.              }
end;

When I put 10 links it sometimes adds duplicates to listbox , or with one link it adds two same links to listbox .
How can I fix it to not show duplicates.My idea was to put it inside tstringlist and check for duplicates and remove them.

Is there any other way.Thanks

Answer 1

You can check to see if it already exists before adding it:

if something then
  if ListBox1.Items.IndexOf(AHttpCli.URL) = -1 then
    ListBox1.items.add(AHttpCli.URL);