应用T2A 编译不通过

使用T2A 编译不通过
CString str1( _T("sdjfkljdskfj"));
LPCSTR pszData1 = T2A((LPTSTR) (LPCTSTR)str1); //line 2193


报错
1>e:\work\eyouim2\chatdialog.cpp(2193) : error C2065: '_lpw' : undeclared identifier
1>e:\work\eyouim2\chatdialog.cpp(2193) : error C2065: '_convert' : undeclared identifier
1>e:\work\eyouim2\chatdialog.cpp(2193) : error C2065: '_acp' : undeclared identifier

请问是怎么回事
头文件已经包含#include "atlbase.h"

[解决办法]

C/C++ code

#include <AFXPRIV.H>...USES_CONVERSION;CString str1( _T("sdjfkljdskfj")); LPCSTR  pszData1  =  T2CA(str1);