实时获取网络时间 并转换为北京时间的函数

unit Unit1;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs,Winapi.msxml, System.DateUtils,
  Vcl.StdCtrls;

type
  TForm1 = class(TForm)
    Button1: TButton;
    Label1: TLabel;
    Label2: TLabel;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}
//实时获取网络时间的函数, 得到的是格林威治时间; 默认从 sohu 服务器获取, 因为它最快, 平均只需 15 毫秒
function GetNetTime(aUrl: WideString = 'http://www.sohu.com'): string;
begin
  with CoXMLHTTP.Create do
  begin
    open('Post', aUrl, False, EmptyParam, EmptyParam);
    send(EmptyParam);
    Result := getResponseHeader('Date');
  end;
end;

//格林威治时间(字符串)转换到北京时间  1
function GMT2BjDateTime(const GMT: string): TDateTime;
var
  A: TArray<string>;
begin
  A := GMT.Split([',', ' '], ExcludeEmpty); //XE4 支持

  with TStringList.Create do begin
    CommaText := 'Jan=1,Feb=2,Mar=3,Apr=4,May=5,Jun=6,Jul=7,Aug=8,Sep=9,Oct=10,Nov=11,Dec=12';
    A[2] := Values[A[2]];
    Free;
  end;

  Result := StrToDateTime(Format('%s/%s/%s %s', [A[3], A[2], A[1], A[4]]), FormatSettings.Create(2052));
  Result := Result + 8/24; //换算成北京时间
end;
//格林威治时间(字符串)转换到北京时间  2
function GMT2BjDateTime2(const GMT: string): TDateTime;
var
  A: TArray<string>;
begin
  A := GMT.Split([',', ' '], ExcludeEmpty); //XE4 支持

  with TStringList.Create do begin
    CommaText := 'Jan=1,Feb=2,Mar=3,Apr=4,May=5,Jun=6,Jul=7,Aug=8,Sep=9,Oct=10,Nov=11,Dec=12';
    A[2] := Values[A[2]];
    Free;
  end;

  Result := StrToDateTime(Format('%s/%s/%s %s', [A[3], A[2], A[1], A[4]]), FormatSettings.Create(2052));
  Result := Result + 8/24; //换算成北京时间
end;
procedure TForm1.Button1Click(Sender: TObject);
var
  strGMT: string;
  bjDateTime: TDateTime;
  bjDateTime2: TDateTime;
begin
  strGMT := GetNetTime();
  bjDateTime := GMT2BjDateTime(strGMT);
  bjDateTime2 := GMT2BjDateTime2(strGMT);

  Label1.Caption:=strGMT + #10 + DateTimeToStr(bjDateTime);
  Label2.Caption:=strGMT + #10 + DateTimeToStr(bjDateTime2);
end;



end.