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Data Conversions

By , 28 Jun 2002
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Introduction

Here are a few data conversions with small examples :-

Decimal Conversions

Decimal To Hex

// Use _itoa( ) function and set radix to 16.

char hexstring[10]; 
int number = 30;
itoa( number, hexstring, 16);

// In hexstring is 1e.

Hex To Decimal

// You can use strtol function and you can specify base. 

char * hexstring= "ABCDEF";
char * p;
int number = strtol(hexstring, &p,16);

//  A function that does this

bool HexToDecimal (char* HexNumber, int& Number)
{ 
    char* pStopString; 
    Number = strtol (HexNumber, &pStopString, 16);
    return (bool)(Number != LONG_MAX);
}

Decimal to time

char *DecToTime(float fTime, char *szTime)
{
    int nHrs, nMin, nSec; 
    fTime *= 3600;
    nHrs = (int)fTime / 3600;
    nMin = (int)(fTime - nHrs * 3600) / 60;
    nSec = (int)(fTime - nHrs * 3600 - nMin * 60);
    wsprintf(szTime, "%02d.%02d.%02d Hrs.Min.Sec.", nHrs, nMin, nSec);
    return szTime;
}

String Conversions

String to Hex

sscanf(string, %04X, &your_word16);
// where string = your string and 
// 04 = length of your string and X = hex

Hex to CString

CString Str;
unsigned char Write_Buff[1];
Write_Buff[0] = 0x01;
Str.Format("0x0%x",Write_Buff[0]);

COleVariant to CString

CString strTemp;
COleVariant Var;
Var = "FirstName";
strTemp = Var.bstrVal;
AfxMessageBox(strTemp);

CString to char pointer

CString MyString = "ABCDEF";
char * szMyString = (char *) (LPCTSTR) MyString;
char *pBuffer = new char[1024];
CString strBuf = "Test";
pBuffer = strBuf.GetBuffer(sizeof(pBuffer));

char pointer to CString

char * mystring = "12345";
CString string = mystring;

Double to CString including the fractional part

CString strValue,strInt, strDecimal;
int decimal,sign;
double dValue = 4.125;
strValue = _fcvt(dValue,6,&decimal,&sign); 
    // Now decimal contains 1 because there is 
    // only one digit before the .

strInt = strValue.Left(decimal); // strInt contains 4
strDecimal = strValue.Mid(decimal); // strDecimal contains 125

CString strFinalVal;
strFinalVal.Format("%s.%s",strInt,strDecimal); 
    // strFinalVal contains 4.125

Double To CString

CString strValue;
int decimal,sign;

double dValue = 123456789101112;
strValue = _ecvt(dValue,15,&decimal,&sign);

CString To Double

strValue = "121110987654321";
dValue = atof(strValue);

CString to LPCSTR

CString str1 = _T("My String");
int nLen = str1.GetLength();
LPCSTR lpszBuf = str1.GetBuffer(nLen);
// here do something with lpszBuf...........
str1.ReleaseBuffer();

CString to LPSTR

CString str = _T("My String");
int nLen = str.GetLength();
LPTSTR lpszBuf = str.GetBuffer(nLen);
// here do something with lpszBuf...........
str.ReleaseBuffer();

CString to WCHAR*

CString str = "A string here" ;
LPWSTR lpszW = new WCHAR[255];

LPTSTR lpStr = str.GetBuffer( str.GetLength() );
int nLen = MultiByteToWideChar(CP_ACP, 0,lpStr, -1, NULL, NULL);
MultiByteToWideChar(CP_ACP, 0, lpStr, -1, lpszW, nLen);
AFunctionUsesWCHAR( lpszW );
delete[] lpszW;

LPTSTR to LPWSTR

int nLen = MultiByteToWideChar(CP_ACP, 0, lptStr, -1, NULL, NULL);
MultiByteToWideChar(CP_ACP, 0, lptStr, -1, lpwStr, nLen);

string to BSTR

string ss = "Girish";
BSTR _bstr_home = A2BSTR(ss.c_str());

CString to BSTR

CString str = "whatever" ;
BSTR resultsString = str.AllocSysString(); 

_bstr_t to CString

#include <ANSIAPI.H>
#include <comdef.h>
_bstr_t bsText("Hai Bayram");
CString strName;
W2A(bsText, strName.GetBuffer(256), 256);
strName.ReleaseBuffer();
AfxMessageBox(strName);

char szFileName[256];
GetModuleFileName(NULL,szFileName,256);
AfxMessageBox(szFileName);

Character arrays

Char array to integer

char MyArray[20];
int nValue;

nValue = atoi(MyArray);

Char array to float

char MyArray[20];
float fValue;

fValue = atof(MyArray);

Char Pointer to double

char *str = " -343.23 "; 
double dVal; 
dVal = atof( str );

Char Pointer to integer

char *str = " -343.23 "; 
int iVal;
iVal = atoi( str );

Char Pointer to long

char *str = "99999"; 
long lVal; 
lVal = atol( str );

Char* to BSTR

char * p = "whatever";
_bstr_t bstr = p;

Float to WORD and Vice Versa

float fVar;
WORD wVar;
fVar = 247.346;
wVar = (WORD)fVar; //Converting from float to WORD. 
    //The value in wVar would be 247

wVar = 247;
fVar = (float)fVar; //Converting from WORD to float. 
    //The value in fVar would be 247.00

Conclusion

All luck and have a great time. I've checked most of the code above, but if I've been wrong somewhere, I'd like to know about it so that I can modify it. Thank you.

License

This article has no explicit license attached to it but may contain usage terms in the article text or the download files themselves. If in doubt please contact the author via the discussion board below.

A list of licenses authors might use can be found here

About the Author

VGirish
Founder
India India
No Biography provided

Comments and Discussions

 
QuestionConversion of BYTE to CString and Viceversa Pinmemberg_satish9-Sep-09 1:02 

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