[MFC] CString <-> char* / int

CString  => char* 변환

char * ch;
CString *str;

1) ch = (LPSTR)(LPCSTR)str;

2) ch = str.GetBuffer(str.GetLength());
3) wsprintf( ch, "%s", str);

char*  =>  CString 변환

1) str = (LPCSTR)(LPSTR)ch;
2) str = ch;

 

CString  =>  int 변환
int a;

CString strTest = _T("abc");

a = _ttoi(strTest);

문자열에서 숫자만 추출하기

CString str = _T("abc123def456");

CString strNumber(_T(""));

for(int i = 0; i < str.GetLength(); i++){

char ch = str.GetAt(i);

if(ch >= '0' && ch <= '9')

strNumber += ch;

}

int final = _ttoi(strNumber);

 

 

// CString -> int convertCString
strNum = _T("5");
int nNum = _ttoi(strNum);

 

 

// int -> CString convertint
nNum = 5;
CString strNum;
strNum.Format(_T("%d"), nNum);

 

 

// CString -> doubleCString
strNum = _T("5.5");
double nNum = _wtof(strNum);

 

 

// double -> CStringdouble
nNum = 5.5;
CString strNum;
strNum.Format(_T("%f"), nNum);

 

 

// Multibyte 기반일 경우// _ttoi -> atoi
// _wtof -> atof 로 바꿔주면 됩니다.

 

참고)

LPSTR 은 char* 입니다.

LPSTR : char stirng의 32비트 포인터, char* 와 같다.

LPCTSTR : Constant character String의 32비트 포인터

UINT : 32비트 unsigned형 정수
DWORD : unsigned long int형

BYTE : 8비트 unsigned 정수

 

 

1.CString 클래스의 GetBuffer()는 CString을 char *로 바꿔줍니다.

ex) CString strTemp = _T("test");
     char *getTemp=NULL;

     getTemp = malloc(strTemp.GetLength()+1);
     strcpy(getTemp, strTemp.GetBuffer(strTemp.GetLength());
     printf("결과:%sn", getTemp);

     free(getTemp);

2. operator LPCTSTR ()도 마찬가지입니다.

ex) CString strTemp = _T("test");
     char *getTemp = (LPSTR)(LPCSTR)strData;

 

 

 

 

 

 

int i=atoi(msg.type);
error C2664: 'atoi' : cannot convert parameter 1 from 'class CString' to 'const char *'
what should I do?

 

 

In this case, you don't need to convert if you use the UNICODE version of atoi, _wtoi. Even better is to use _ttoi, which is the TCHAR version and will work for both UNICODE and MBCS: If UNICODE is defined, it will accept a const wchar_t*, if not, a const char*. You don't even need the explicit cast to LPCTSTR, as it will be invoked automatically:

 

Code: int i=_ttoi(msg.type);

And please don't listen to people who tell you to use CString::GetBuffer() in this situation, they don't know what they are talking about. GetBuffer() is used exclusively to gain write access to CString's internal buffer, not to convert from CString to char*. And if you don't be careful to match every GetBuffer() call with ReleaseBuffer(), using that CString object will produce unpredictable results.