#include <math.h> #ifndef _CRT_SECURE_CPP_OVERLOAD_STANDARD_NAMES #define _stprintf_s _stprintf #define _tcscat_s _tcscat #endif //#ifndef _CRT_SECURE_CPP_OVERLOAD_STANDARD_NAMES LPCTSTR Double2Str(long double fVal) { static TCHAR chStr[256]; memset(chStr, 0, sizeof(chStr)); _stprintf_s(chStr, _T("%+I64d"), (__int64)fVal); long double fRem = fabs(fVal - (__int64)fVal); _tcscat_s(chStr, _T(".")); do { fRem *= 10.0; TCHAR chSub[] = { _T('0' + (int)fRem), _T('\0') }; _tcscat_s(chStr, chSub); fRem = fRem - (int)fRem; }while(fRem != 0); TRACE(_T("fVal = %f == >%s\n"), fVal, chStr); return chStr; }
//测试 double fVal = 4 * atan(1.0); Double2Str(fVal);
/*输出 fVal = 3.141593 == >+3.141592653589793115997963468544185161590576171875 当然8字节的双精度数据有效位为16位,之后的也就没有实际意义了 */