(1)string --> char *  string str("OK");  char * p = str.c_str();(2)char * -->string  char *p = "OK";  string str(p);(3)char * -->CString   char *p ="OK";  CString m_Str(p);  //或者  CString m_Str;  m_Str.Format("%s",p);(4)CString --> char *  CString str("OK");  char * p = str.GetBuffer(0);  ...  str.ReleaseBuffer();(5)string --> CString   CString.Format("%s", string.c_str()); (6)CString --> string  string s(CString.GetBuffer(0));   GetBuffer()后一定要ReleaseBuffer()，否則就沒有釋放緩沖區所占的空間，CString對象不能動態增長了。(7)double/float->CString  double data;  CString.Format("%.2f",data); //保留2位小數(8)CString->double  CString s="123.12";  double  d=atof(s);   (9)string->double double d=atof(s.c_str());

char str[10];int a=1234321;sprintf(str,"%d",a);--------------------char str[10];double a=123.321;sprintf(str,"%.3lf",a);--------------------char str[10];int a=175;sprintf(str,"%x",a);//10進制轉換成16進制，如果輸出大寫的字母是sprintf(str,"%X",a)--------------------char *itoa(int value, char* string, int radix); 

char str[]="1234321";int a;sscanf(str,"%d",&a);.............char str[]="123.321";double a;sscanf(str,"%lf",&a);.............char str[]="AF";int a;sscanf(str,"%x",&a); //16進制轉換成10進制

 ostringstream s1; int i = 22; s1 << "Hello " << i << endl; string s2 = s1.str(); cout << s2;

 istringstream stream1; string string1 = "25"; stream1.str(string1); int i; stream1 >> i; cout << i << endl; // displays 25