CString TO Double (zz)

//z 2013-10-21 15:01:30 IS2120@BG57IV3 T3345574402.K.F3396121938[T3,L303,R3,V37]

1. atl CString 转换成 double 浮点数

A CString can convert to an LPCTSTR, which is basically a const char* (const wchar_t*atof():

CString thestring("13.37");
double d = atof(thestring).

_wtof():

CString thestring(L"13.37");
double d = _wtof(thestring).

...or to support both Unicode and non-Unicode builds...

CString thestring(_T("13.37"));
double d = _tstof(thestring).

_tstof() is a macro that expands to either atof() or _wtof() based on whether or not_UNICODE is defined)

//z 2013-10-21 15:01:30 IS2120@BG57IV3 T3345574402.K.F3396121938[T3,L303,R3,V37]

2. 使用 std::stringstreamanything to anything using a std::stringstream. The only requirement is that the operators >> and << be implemented. Stringstreams can be found in the <sstream>

std::stringstream converter;
converter << myString;
converter >> myDouble;

//z 2013-10-21 15:01:30 IS2120@BG57IV3 T3345574402.K.F3396121938[T3,L303,R3,V37]

3. lexical_cast

#include <boost/lexical_cast.hpp>
using namespace boost;

...

double d = lexical_cast<double>(thestring);

4. 

strtod

strtod (or wcstod) will convert strings to a double-precision value.

<stdlib.h> or <wchar.h>)

Example

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/* strtod example */
#include <stdio.h>      /* printf, NULL */
#include <stdlib.h>     /* strtod */

int main ()
{
  char szOrbits[] = "365.24 29.53";
  char* pEnd;
  double d1, d2;
  d1 = strtod (szOrbits, &pEnd);
  d2 = strtod (pEnd, NULL);
  printf ("The moon completes %.2f orbits per Earth year.\n", d1/d2);
  return 0;
}

Output:

//z 2014-02-20 16:26:18 IS2120@BG57IV3 T3529903025.K.F3153028746[T372,L4642,R198,V6937]
2. 删除字符串结尾的 0

[email protected]
//z 2014-02-20 16:16:02 IS2120@BG57IV3 T707139593 .K.F3153028746[T371,L4620,R198,V6936]
void removeTrailingZeros(char pio_cText[])
{
    char* pCh = strchr(pio_cText,'.');

    if(pCh!=NULL)
    {
        int iLen = static_cast<int>(strlen(pio_cText));
        char* pPos = pio_cText + iLen -1;

        while(*pPos == '0')
        {
            *(pPos--) = '\0';
        }

        if(*pPos == '.')
        {
            *pPos= '\0';
        }
    }
}[email protected]