3 实现过程

3．1新建一个表单

在这个表单的INIT事件中写入如下代码来定义注册表API函数所用到的常量和引入注册表API函数：

PUBL HCROOT,DEFINE HCUSER,DEFINE HLMACHINE,HKEY_USERS,ERRORXX

HCROOT=-2147483648

HCUSER=-2147483647

HLMACHINE=-2147483646

HKEY_USERS=-2147483645

ERRORXX=0

DECLARE INTEGER RegOpenKey IN WIN32API INTEGER NHKEY,STRING CSUBKEY,INTEGER @NHANDLE

DECLARE INTEGER RegCreateKey IN Win32API INTEGER NHKEY,STRING CSUBKEY,INTEGER @NHANDLE

DECLARE INTEGER RegCloseKey IN WIN32API INTEGER NHKEY

DECLARE INTEGER RegDeleteKey IN WIN32API INEGER NHKEY,STRING CSUBKEY

DECLARE INTEGER RegDeleteValue IN WIN32API INTEGER NHKEY,STRING CENTRY

usetime=thisform.myreadregistrystring(HLMACHINE,"SOFTWARE\testtime","thistime")

IF ISNULL(usetime)

  =THISFORM.MYREGCREATEKEY(HLMACHINE,"SOFTWARE\testtime",0)

  =THISFORM.mywriteregistrystring(HLMACHINE,"SOFTWARE\testtime","thistime","30")

   messagebox("注意：你可以免费使用30次本系统，请及时注册购买正版软件","提示窗口")

ELSE

  IF Val(usetime)=1

    messagebox("使用次数已到，请购买正版软件","提示窗口")

  ELSE