In system configurations it is very common to have to inform

a standard printer to automate some task.

Right. We can manually enter the printer share name
or we can create a way for the user to choose easily.

Using TPrinterDialog, the system will make use of Windows’ own search!

Let’s go to the code!

I will put the whole unit to facilitate understanding.

unit Unit2;
 
interface
 
uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls;
 
type
  TForm2 = class(TForm)
    Button1: TButton;
    PrintDialog1: TPrintDialog;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
 
var 
  Form2 : TForm2 ;
 
implementation
 
{$R *.dfm}
 
uses 
  {Very important to declare this unit} 
  Vcl . Printers ;
 
procedure TForm2 . Button1Click ( Sender :  TObject ) ; 
begin 
  if PrintDialog1 . Run  then 
  begin 
    // Displaying the selected printer !!! 
    ShowMessage ( 
      Printer . Printers [ Printer . PrinterIndex  ] ) ; 
  end ; 
end ;
 
end.

So we can see at the click of a button the printer selects, making it
much easier for the end user.