详测 Generics Collections TList (3): Insert、Delete、Remove、Extract

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

uses Generics.Collections;

procedure TForm1.Button1Click(Sender: TObject);
var
  List: TList<Integer>;
  i: Integer;
  str: string;
begin
  List := TList<Integer>.Create();
  List.Add(111);
  List.Add(222);
  List.Add(333);

  List.Insert(0, 444);
  List.Insert(2, 555);

  str := '';
  for i in List do str := str + UIntToStr(i) + ' '; {444 111 555 222 333 }
  ShowMessage(str);

  List.Delete(0);
  List.Delete(List.Count-1);

  str := '';
  for i in List do str := str + UIntToStr(i) + ' '; {111 555 222 }
  ShowMessage(str);

  List.Remove(555); {删除指定元素}

  str := '';
  for i in List do str := str + UIntToStr(i) + ' '; {111 222 }
  ShowMessage(str);

  List.Extract(222); {提取指定元素}

  str := '';
  for i in List do str := str + UIntToStr(i) + ' '; {111 }
  ShowMessage(str);
  
  List.Free;
end;

end.