[轉貼]C++ vector 使用方法

#include vector

using namespace std;

vector v1;
vector ::iterator Iter1;

v1.push_back( 10 ); // 丟一個 integer 進去 vector
v1.push_back( 19 );

// v1.begin() : vector 的最前面
// v1.end() : vector 的最後面

for( Iter1 = v1.begin(); Iter1 < v1.end(); Iter1++ ){
cout << *Iter1 << ", "; // 取值，印出
}

cout << endl;
// 移除 第一個 Element
v1.erase (v1.begin());

// 移除 前兩個 Element
v1.erase (v1.begin(), v1.begin() + 1);

Data Conversions for C++

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 thefractional 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 
#include 
_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

[轉貼]char和wchar的轉換

因為在之前的開發中~都是使用char宣告變數比如在用sprintf~~textout等函式都是用char的型態
但在使用vs2005之後都要改變成wchar才能執行雖然知道字串可以使用_T("字串")來轉成wchar
但如果是char和wchar之間的轉換有什麼方法嗎?

MultiByteToWideChar與WideCharToMultiByte

EX:
WCHAR * AnsiToUnicode(const char *str)
{
if( str == NULL ) return NULL;
int len = (int)strlen(str);
int nLen = ::MultiByteToWideChar(CP_ACP, 0,(char *)str, -1, NULL, NULL);
LPWSTR lpszW = new WCHAR[nLen];
::MultiByteToWideChar(CP_ACP, 0,(char *)str, len, lpszW, nLen);
lpszW[nLen-1] = 0;
return lpszW;
}

//回傳指標用完記得殺掉