Delphi实现限定软件使用时间的方法

unit Unit1;interfaceuses Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Registry, Dialogs;type TForm1 = class(TForm)  procedure FormCreate(Sender: TObject); private  { Private declarations } public  { Public declarations } end;var Form1: TForm1;implementation{$R *.DFM}procedure TForm1.FormCreate(Sender: TObject);var  registerTemp : TRegistry;  curDate : TDateTime;begin  registerTemp := TRegistry.Create;  with registerTemp do  begin    RootKey := HKEY_LOCAL_MACHINE;    //判断是否初次运行程序    if OpenKey('Software/MySoftware',True) then    begin      if ReadBool('Runned') then      //不是第一次运行      begin        curDate := Date;        if (curDate-ReadTime('LastRunTime'))>=ReadInteger('Duration') then        begin          //当前的系统时间超出了使用期限          ShowMessage('试用版已到期');          exit;        end        else        begin          DeleteKey('LastRunTime');          WriteTime('LastRunTime',Date);        end;      end      else      begin        //初次运行程序        DeleteKey('Runned');        WriteBool('Runned',True);        //设置试用期限30天        WriteInteger('Duration',30);        //写入当前运行时间        WriteTime('LastRunTime',Date);      end;    end    else    begin      ShowMessage('Fails!');    end;    CloseKey;  end;end;end.