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* in Unicode builds).

Knowing this, you can use atof():

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

...or for Unicode builds, _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::stringstream

You can convert anything to anything using a std::stringstream. The only requirement is that the operators >> and << be implemented. Stringstreams can be found in the <sstream> header file.

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.

(Requires <stdlib.h> or <wchar.h>)

Example

1 2 3 4 5 6 7 8 9 10 11 12 13 14

/* 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:

The moon completes 12.37 orbits per Earth year.


//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

IS2120@CSDN.BG57IV3
//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';
        }
    }
}IS2120@CSDN.BG57IV3