Query information for a Tlistview-related Tabsheet

Question

Well I’m a beginner and I’m in big trouble.

I have the following situation:

I create an item on Tlistview by making two clicks on the selected item I add an object in the form to the item of listview and create a form with parent at the Tabsheet.

In this case what I’m not getting is to relate the Tabsheet to the item when I close the form or delete the item. I was able to do just by adding the handle of Tabsheet to the selected item, I do the loop of handle to identify which tabsheet this related to the item.

In the ondblclick of listview:

LV1.Selected.SubItems[1]:=IntToStr(NewTabSheet.Handle);
LV1.Selected.SubItems.Objects[3] := TObject(NewTabSheet);

In the onChange of PageControl I try to identify the tabsheet:

procedure TForm1.pgc1Change(Sender: TObject);
var
  i, c: integer;
begin
  try
    for i := 0 to lv1.Items.Count -1 do
      if i > 0 then
      begin
        if IntToStr(pgc1.ActivePage.Handle) = Form1.lv1.Items.Item[i].SubItems[1] then
        begin
          lv1.Items.Item[i].Selected:= True;
          Abort;
        end;
      end;
   // ...

Here is when I try to set some item information when I change tabsheet:

procedure TForm1.SENDTEXT(txt:string;NUM:INTEGER);
var
  i,c:integer;
begin
  for i := 0 to Form1.LV1.Items.count - 1 do
  begin
    if form1.lv1.Items[i].SubItems[1] = inttostr(pgc1.ActivePage.Handle) then
    begin
      (form1.lv1.Items[i].SubItems.Objects[2]as TForm2).StatusText.Panels[NUM].Text:=txt;
    end;
  end;
end;

Correct me because I’m getting lost in the code, I think my method is wrong!

Answer 1

Do the following:

1. Declare the function below to identify the Form2 from the PageControl:

   function IdentificarFormulario(PageControl: TPageControl): TForm2;
   var
     tab: TTabSheet;
     I: Integer;
   begin
     Result := nil;
     tab := PageControl.ActivePage;
     for I := 0 to tab.ControlCount- 1 do
       if tab.Controls[I] is TForm then
       begin
         Result := TForm2(tab.Controls[I]);
         Break;
       end;
   end;
   

2. At the event OnDblClick of Listview, check if there are any items selected before assigning information to Listview:

   // Se não houver nada selecionado, o código abaixo não será executado
   if LV1.Selected = nil then exit;
   
   LV1.Selected.SubItems[1] := IntToStr(NewTabSheet.Handle);
   
   // Onde "PGC1" é o componente "PageControl"
   LV1.Selected.SubItems.Objects[3] := IdentificarFormulario(PGC1);
   

3. Change your job function SENDTEXT to keep it that way:

   procedure SENDTEXT(txt: string; NUM: INTEGER);
   var
     I: integer;
   begin
     for I := 0 to LV1.Items.Count - 1 do
       if (LV1.Items.Item[I] <> nil) and
          (LV1.Items.Item[I].SubItems[1] = IntToStr(pgc1.ActivePage.Handle))
       then
         TForm2(LV1.Items.Item[I].SubItems.Objects[3]).StatusText.Panels[0].Text := txt;
   end;
   

4. At the event onChange of PageControl, all that code is unnecessary (I think), just call the function SENDTEXT:

   // Onde "texto" é a informação que você quer mostrar no "StatusText" do "Form2"
   // O segundo argumento é índice do "Panel" do "StatusText"
   SENDTEXT('Texto', 0);