Delphi 10.2 Tokyo新增JSON类学习——TJsonSerializer

Delphi 10.3.2 for windows 7 编译通过，源码下载地址：

Tokyo 10.2新增类，效率更高更快

TJsonSerializer

需要引用单元：System.JSON.Serializers

unit uMain;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants,
  System.Classes, Vcl.Graphics, Vcl.Controls, Vcl.Forms, Vcl.Dialogs,
  Vcl.ComCtrls, Vcl.StdCtrls, Vcl.ExtCtrls, Vcl.Samples.Spin, Vcl.Buttons;

type
  TObj1 = class
  private
    F_i: Integer;
    f_d: TDateTime;
    f_s: string;
  //  f_a: TArray<string>;
  public
    constructor Create;
  published
    property field_s: string read f_s write f_s;
    property field_i: Integer read F_i write F_i;
    property field_d: TDateTime read f_d write f_d;
  //  property field_a: TArray<string> read f_a write f_a;
  end;

  TfrmJSONText = class(TForm)
    btn1: TButton;
    mmolog: TMemo;
    SpeedButton1: TSpeedButton;
    seTestNumber: TSpinEdit;
    lbl1: TLabel;
    procedure FormCreate(Sender: TObject);
    procedure btn1Click(Sender: TObject);
    procedure Log(const S: string);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  frmJSONText: TfrmJSONText;
  TestNumber: Integer;

implementation

uses
  System.Diagnostics
  {$IF CompilerVersion>31.0}
    , System.JSON.Serializers, System.JSON.Types
  {$ENDIF}
;
{$R *.dfm}

procedure TfrmJSONText.btn1Click(Sender: TObject);
{$IF CompilerVersion>31.0}
var
  Foo: TObj1;
  I: Integer;
  sw: TStopwatch;
  AJson: string;
  Serializer: TJsonSerializer;
{$ENDIF}
begin
{$IF CompilerVersion>31.0}
  TestNumber := seTestNumber.Value;
  sw := TStopwatch.StartNew;
  Serializer := TJsonSerializer.Create;
  try
    Serializer.DateTimeZoneHandling := TJsonDateTimeZoneHandling.Utc;
    for I := 0 to TestNumber - 1 do
    begin
      Foo := TObj1.Create;
      try
        Foo.field_s := 'Hello World';
        Foo.field_i := 42;
        Foo.field_d := Now;
        AJson := Serializer.Serialize<TObj1>(Foo);
      finally
        Foo.Free;
      end;

    end;
    Log('TJsonSerializer.Serialize：' + sw.ElapsedMilliseconds.ToString + ' ms ' + AJson);

    sw := TStopwatch.StartNew;
    for I := 1 to TestNumber - 1 do
    begin
      Foo := Serializer.Deserialize<TObj1>(AJson);
      try
      finally
        Foo.Free;
      end;
    end;
    Log('TJsonSerializer.Deserialize：' + sw.ElapsedMilliseconds.ToString + ' ms');

  finally
    FreeAndNil(Serializer);
  end;
  Log('=======================');
{$ENDIF}

end;

procedure TfrmJSONText.FormCreate(Sender: TObject);
const
  // D2010~D10.3
  DelphiIDEVers: array[21..33] of string = ('Delphi 2010', 'Delphi XE', 'Delphi XE2', 'Delphi XE3', 'Delphi XE4', 'Delphi XE5', 'Delphi XE6', 'Delphi XE7', 'Delphi XE8', 'Delphi 10 Seattle', 'Delphi 10.1 Berlin', 'Delphi 10.2 Tokyo', 'Delphi 10.3 Rio');
begin
{$IFDEF WIN64}
  Caption := Caption + ' (64-bit)';
{$ENDIF}
{$IFDEF WIN32}
  Caption := Caption + ' (32-bit)';
{$ENDIF}

  Caption := Caption + ' - ' + DelphiIDEVers[Trunc(CompilerVersion)];

{$IF CompilerVersion<32.0}    //版本小于Delphi 10.2 ，button Enabled false
  btn1.Enabled := False;
{$ENDIF}
end;

procedure TfrmJSONText.Log(const S: string);
begin
  mmoLog.Lines.Add(S);
end;

{ TObj1 }

constructor TObj1.Create;
begin
  inherited;
end;

end.