Creating custom button in Delphi with different actions [closed] - delphi

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I am creating a custom component, a button-switch like this :
In my "form activate" function, I wrote a for loop in which I call 3 times the button function with a different position parameter like : SwitchButton(30); where 30 is the top position.
What I want to do is assign at these 3 buttons different actions, here some code.
Code for button creation :
procedure TFMain.SwitchButton(posPulsante: Integer);
var
i: Integer;
posDescrizionePulsante: Integer;
strDescrizione: String;
begin
posDescrizionePulsante := 32;
lastPressed := 1;
Pulsante := TPanel.Create(FMain);
BordoPulsante := TShape.Create(self);
LevaPulsante := TPanel.Create(self);
DescrizionePulsante := TLabel.Create(self);
//Proprietà Descrizione
with DescrizionePulsante do
begin
Parent := PComandi;
Top := posDescrizionePulsante;
Left := 100;
Caption := 'Visualizza finestra utenti';
Font.Name := 'Tahoma';
Font.Size := 12;
Font.Style := [fsBold];
Font.Color := clWhite;
end;
//Proprietà Pulsante
with Pulsante do
begin
Parent := PComandi;
ParentColor := false;
ParentBackground := false;
BevelOuter := bvNone;
Color := clWhite;
Width := 57;
Height := 25;
Top := posPulsante;
Left := 20;
Visible := true;
end;
//Proprietà Bordo
with BordoPulsante do
begin
Parent := Pulsante;
Align := alClient;
Brush.Style := bsClear;
Brush.Color := RGB(122,136,201);
Pen.Color := clWhite;
Pen.Style := psSolid;
Pen.Width := 3;
end;
//Proprietà Leva
with LevaPulsante do
begin
Parent := Pulsante;
ParentBackground := false;
ParentColor := false;
BevelOuter := bvNone;
Color := clWhite;
Cursor := crHandPoint;
Width := 23;
Height := 13;
Top := 6;
Left := 28;
LevaPulsante.OnClick := SwitchState;
end;
end;
Code for creating Button object :
procedure TFMain.FormActivate(Sender: TObject);
var
i: Integer;
posPulsante: Integer;
begin
posPulsante := 30;
for i := 1 to 3 do
begin
SwitchButton(posPulsante);
posPulsante := posPulsante + 50;
end;
end;
Would be nice to have some : if SwitchButton 1 is clicked then do something. if SwitchButton 2 is clicked then do something else.

Answer 1

I think this is an acceptable use of the Tag property. You can specify some number, for example the index of the for loop, in each of the panels:
procedure TFMain.FormActivate(Sender: TObject);
var
i: Integer;
posPulsante: Integer;
begin
posPulsante := 30;
for i := 1 to 3 do
begin
SwitchButton(posPulsante, i {For example, add the tag as extra parameter});
posPulsante := posPulsante + 50;
end;
end;
And then set that tag in the button, here using the added parameter indexPulsante.
procedure TFMain.SwitchButton(posPulsante: Integer; indexPulsante: Integer);
var
i: Integer;
posDescrizionePulsante: Integer;
strDescrizione: String;
begin
...
LevaPulsante.Tag := indexPulsante;
end;
And then, in the event handler (which I think you called SwitchState), you'll have the Sender, which is the control that was clicked (the panel, in your case).
procedure TFMain.SwitchState(Sender: TObject);
begin
case (Sender as TComponent).Tag of
1: ShowMessage('You clicked the first. Do something.')
2: ShowMessage('Do something else.')
else
ShowMessage('You clicked another button than 1 or 2');
end;
end;
NB: Tag is introduced in TComponent and therefore also available in TPanel. In the code above I only typecast to TComponent, because it doesn't matter that it's a panel to get the tag, but if you want to use other properties, a more specific cast may be needed. I like to keep the cast generic, to make it easier to make changes like switching to another type than TPanel, for instance when you actually gonna make a component out of this (inherited from TCustomControl?), or use a third party component.