詳細測定Generics Collections TDictionary(4):OnKeyNotify、OnValueNotify

unit Unit1;



interface



uses

  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

  Dialogs, StdCtrls, Generics.Collections;



type

  TForm1 = class(TForm)

    Button1: TButton;

    procedure Button1Click(Sender: TObject);

  private

    procedure KeyNotify(Sender: TObject; const Item: string;

      Action: TCollectionNotification);

    procedure ValueNotify(Sender: TObject; const Item: Integer;

      Action: TCollectionNotification);

  end;



var

  Form1: TForm1;



implementation



{$R *.dfm}



procedure TForm1.KeyNotify(Sender: TObject; const Item: string;

  Action: TCollectionNotification);

begin

  case Action of

    cnAdded     : ShowMessageFmt('Key_Add: %s', [Item]);

    cnRemoved   : ShowMessageFmt('Key_Remove: %s', [Item]);

    cnExtracted : ShowMessageFmt('Key_Extract: %s', [Item]);

  end;

end;



procedure TForm1.ValueNotify(Sender: TObject; const Item: Integer;

  Action: TCollectionNotification);

begin

  case Action of

    cnAdded     : ShowMessageFmt('Value_Add: %d', [Item]);

    cnRemoved   : ShowMessageFmt('Value_Remove: %d', [Item]);

    cnExtracted : ShowMessageFmt('Value_Extract: %d', [Item]);

  end;

end;  



procedure TForm1.Button1Click(Sender: TObject);

var

  Dictionary: TDictionary<string,Integer>;

begin

  Dictionary := TDictionary<string,Integer>.Create();

  Dictionary.OnKeyNotify := KeyNotify;

  Dictionary.OnValueNotify := ValueNotify;



  Dictionary.Add('n1', 111); {Key_Add: n1;  Value_Add: 111}

  Dictionary.Add('n2', 222); {Key_Add: n2;  Value_Add: 222}



  Dictionary.AddOrSetValue('n1', 123); {Value_Remove: 111;  Value_Add: 123}



  Dictionary.Remove('n1');      {Key_Remove: n1;  Value_Remove: 111}



  Dictionary.ExtractPair('n2'); {Key_Extract: n2;  Value_Extract: 222}



  Dictionary.OnKeyNotify := nil;

  Dictionary.OnValueNotify := nil;

  

  Dictionary.Free;

end;



end.