How can I optimize this code by using SENDER?

Question

I have a form that contains 16 TCheckBox and 32 TEditBox. Every 2 TEditBox en-ability is depending of the checkBox state. so I uses this code which is too long:

//T1
procedure TOFAddForm.T1Click(Sender: TObject); 
begin
     Q1.Enabled:=T1.Checked;
     P1.Enabled:=T1.Checked; 
     Q1.OnChange(Sender);
end;

.  
.
.

//T16
procedure TOFAddForm.T16Click(Sender: TObject); 
begin
     Q16.Enabled:=T16.Checked;
     P16.Enabled:=T16.Checked;
     Q1.OnChange(Sender);
end;`

I used this code but nothing happen:

procedure TOFAddForm.T1Click(Sender: TObject);
var Q, P: TEdit;
begin
     with  Sender as TCheckBox do begin
           Q.Name:='Q'+copy(Name,1,2);
           P.Name:='P'+Copy(Name,1,2);
           Q.Enabled:=Checked;
           P.Enabled:=Checked;
     end;
     Q1.OnChange(Sender);
end;

thank you.

Answer 1

If all the checkboxes and edits are consistently named, you can add this OnClick event to all checkboxes:

procedure TOFAddForm.TClick(Sender: TObject);
var 
  C: TCheckBox;
  Q, P: TEdit;
  N: string;
begin
  C := Sender as TCheckBox;
  N := Copy(C.Name, 2, Length(C.Name));
  Q := FindComponent('Q' + N) as TEdit;
  P := FindComponent('P' + N) as TEdit;
  Q.Enabled := C.Checked;
  P.Enabled := C.Checked;
  Q.OnChange(Sender);
end;

Answer 2

I suggest you store the TEdit pointers into an array and then use the TCheckBox.Tag property as an index into the array, eg:

var
  Edits: array[0..15, 0..1] of TEdit;

procedure TOFAddForm.FormCreate(Sender: TObject);
var
  K: Integer;
begin
  for k := 0 to 15 do
  begin
    Edits[k, 0] := FindComponent('Q' + IntToStr(k+1)) as TEdit;
    Edits[k, 1] := FindComponent('P' + IntToStr(k+1)) as TEdit;
    (FindComponent('T' + IntToStr(k+1)) as TCheckBox).Tag := k;
end;

procedure TOFAddForm.T1Click(Sender: TObject);
begin
  with Sender as TCheckBox do
  begin
    Edits[Tag, 0].Enabled := Checked;
    Edits[Tag, 1].Enabled := Checked;
    Edits[Tag, 0].OnChange(Sender);
  end;
end;

Answer 3

I would strongly advise in cases like this to create the controls yourself. In the OnCreate event handler, call TEdit.Create(Self), store the object reference in a data structure you manage yourself, e.g. a dynamic array, set properties like Parent, SetBounds and eventhandlers, and look-up Sender in your collection of object references (optionally depending on the value of Tag), this is almost always more performant than using FindComponent.

Added bonusses are you can alter the number of repeating controls easily (even make it dynamic at run-time!) and the dfm-code (which is embedded into the final executable) contains less almost-identical repeating data.