2个字符的字符串转换成2位16进制数有关问题

2个字符的字符串转换成2位16进制数问题
要求把一个有2个字符的字符串转换成2位16进制数.

例子:
  字符串 16进制数
  "00"...."09" "0X00"...."0X09"
  "0A"...."0F" "0X0A"...."0X0F"
  "10"...."09" "0X10"...."0X19"
  "A0"...."A9" "0XA0"...."0XA9"
  "F0"...."FF" "0XF0"...."0XFF"

[解决办法]

C/C++ code

String str = "00";int n = String("0x" + str).ToIntDef(0);