Change the font of all elements in Delphi

For all inheritors from TWinControl Font property can be inherited from the parent container. The ParentFont property is responsible for this. Therefore, if you change the Font of a form, it will also change for all elements nested in this form with ParentFont = True (and then cascade from container to content).

UPD: Enumerate all components of the form with the filter of those classes in which you need to change the font:

 for i := 0 to Form1.Components - 1 do begin if Form1.Components[i] is TButton then TButton(Form1.Components[i]).Font := MyFont else if Form1.Components[i] is TLabel then TLabel(Form1.Components[i]).Font := MyFont else // ... и так далее ... end; 

 for i := 0 to Form1.ControlCount - 1 do case Form1.Controls[i].ClassName of "TLabel", "TButton" { ... типы имеющие свойство font }: (TLabel)(Form1.Controls[i]).Font = NewFont; { может быть некоторые элементы также нужно рекурсивно перебирать } end; 

something like this, with an enumeration of all controls. I can allow syntax errors.

for Delphi it will look like this:

 type
   TMyControl = class (TControl)
   public
     property Font;
   end; 

 procedure SetFontByComponent (comp: TComponent; font: string);
 var
      i: Integer;
   ctrl: TControl;
 begin
   for i: = 0 to comp.ComponentCount-1 do
     if comp.Components [i] is TControl then
       (TMyControl (comp.Components [i])). Font.Name: = font;
 end;

 procedure TForm1.btn1Click (Sender: TObject);
 begin
   SetFontByComponent (self, 'Verdana');
 end;

I solve this problem in C ++ Builder like this, including for TLabel, etc., including all child objects:

1. Create your own class to get public access to the Font property.

  class TMyControl: public TControl
     {
       public:
         __property Font;
     };

2. Next, we iterate over all the components except the top menu.

       AnsiString Name ("Verdana");
       for (int i = 0; iComponentCount; ++ i)
       {
         TControl * ctrl = dynamic_cast <TControl *> (this-> Components [i]);
         if (NULL == ctrl) continue;
         ((TMyControl *) ctrl) -> Font-> Name = Name;
       };