Delphi - Already opened tab in pagecontrol

Question

This is about PageControl with dynamic tabs. I have 5 buttons (Button1, Button2, Button3, Button4, Button5).

I want the following:

1. Each click on a button will open a new TtabSheet.
2. When clicked on the same button the 'Ttabsheet' already opened, should be shown again.

How to do this?

Answer 1

I don't know why you really want to have five buttons doing the job of creating the tabs and then selecting them, but this is one of the approaches you can try

uses System.Generics.Collections;

...

var
Newtabsheet: Ttabsheet;
Tabs: TList<Ttabsheet>;
Index: array[1..5] of Integer;
Ex: array [1..5] of Boolean;

implementation

Put this on the Formcreate handler

procedure TForm6.FormCreate(Sender: TObject);
begin
Tabs := Tlist<Ttabsheet>.create;
for I=1 to 5 do ex[I]:=false;
end;

And this on each OnClickButton event handler

procedure TForm6.Button1Click(Sender: TObject);
begin
if not(Ex[1])then
  begin
  Newtabsheet := Ttabsheet.Create(PageControl1);
  NewTabSheet.PageControl := PageControl1;
  Newtabsheet.Caption := 'Tab 1';
  Index[1] := Tabs.Count;
  Tabs.Add(Newtabsheet);
  Ex[1] := true;
  end
else
  begin
  Pagecontrol1.ActivePage := Tabs.List[Index[1]];
  end;
end;

procedure TForm6.FormClose(Sender: TObject; var Action: TCloseAction);
begin
Tabs.Free;
end;

Remember changing the numbers.

It is tested on RAD studio Seattle.

Note: based on david comments I have edited my answer. and for further explanation please see this question