二进制、十进制以及十六进制之间的相互转换

//将进制的一个字符转换为十进制的数

unsigned char CDushujuDlg::BtoH(char ch)
{
	//0-9
	if (ch >= '0' && ch <= '9')
		return (ch - '0');
	//9-15
	if (ch >= 'A' && ch <= 'F')
		return (ch - 'A' + 0xA);
	//9-15
	if (ch >= 'a' && ch <= 'f')
		return (ch - 'a' + 0xA);
	return(255);
}

//转换十进制数
void CDushujuDlg::OnDecimalConv()
{
	UpdateData(TRUE);
	//先转换为二进制
	m_strBinary = DecimalToBinary(m_strDecimal);
	//再转换为十六进制
	m_strHex = BinaryToHex(m_strBinary);
	UpdateData(FALSE);
}

//转换二进制数
void CDushujuDlg::OnBinaryConv()
{
	UpdateData(TRUE);
	//转换为十进制
	m_strDecimal = BinaryToDecimal(m_strBinary);
	//转换为十六进制
	m_strHex = BinaryToHex(m_strBinary);
	UpdateData(FALSE);
}

//转换十六进制数
void CDushujuDlg::OnHexConv()
{
	UpdateData(TRUE);
	//先转换为二进制
	m_strBinary = HexToBinary(m_strHex);
	//再转换为十进制
	m_strDecimal = BinaryToDecimal(m_strBinary);
	UpdateData(FALSE);
}

//转换十六进制为二进制
CString CDushujuDlg::HexToBinary(CString strHex)
{
	int nLenth = strHex.GetLength();
	char* Hex = new char[nLenth];
	Hex = strHex.GetBuffer(0);
	CString strBinary = _T("");
	for(int i=0;i<nLenth;i++)
	{
		//转换一位十六进制数为十进制
		char h = Hex[nLenth - 1 - i];
		int  j = BtoH(h);
		CString str;
		str.Format(_T("%d"),j);
		//转换十进制为为二进制
		str = DecimalToBinary(str);
		strBinary += str;
	}
	return strBinary;
}

//转换二进制为十六进制
CString CDushujuDlg::BinaryToHex(CString strBinary)
{
	int nLength = strBinary.GetLength();
	CString str = strBinary;
	//位数不是四的倍数时补齐
	switch (nLength % 4)
	{
	case 0:
		break;
	case 1:
		strBinary.Format(_T("%d%d%d%s"), 0, 0, 0, str);
		break;
	case 2:
		strBinary.Format(_T("%d%d%s"), 0, 0, str);
		break;
	case 3:
		strBinary.Format(_T("%d%s"), 0, str);
		break;
	default:
		return _T("");
		break;
	}
	CString strHex, str1;
	str1 = _T("");
	nLength = strBinary.GetLength();
	for(int i = 1; i <= (nLength / 4); i++)
	{
		//每四位二进制数转换为一十六进制数
		str = strBinary.Left(4);
		CString strDecimal = BinaryToDecimal(str);
		int nDecimal = atoi(strDecimal.GetBuffer(0));
		if (nDecimal < 10)
			str1.Format(_T("%d"), nDecimal);
		else
		{
			char c = 'A' + (nDecimal - 10);
			str1.Format(_T("%c"), c);
		}
		strHex += str1;
		strBinary = strBinary.Right(strBinary.GetLength() - str.GetLength());
	}
	return strHex;
}

//转换十进制为二进制
CString CDushujuDlg::DecimalToBinary(CString strDecimal)
{
	int nDecimal = atoi(strDecimal.GetBuffer(0));
	int nYushu; //余数
	int nShang; //商
	CString strBinary = _T("");
	char buff[2];
	CString str = _T("");
	BOOL bContinue = TRUE;
	while (bContinue)
	{
		nYushu = nDecimal % 2;
		nShang = nDecimal / 2;
		sprintf(buff, _T("%d"), nYushu);
		str = strBinary;
		strBinary.Format(_T("%s%s"), buff, str);
		nDecimal = nShang;
		if (nShang == 0)
			bContinue = FALSE;
	}
	return strBinary;
}

//转换二进制为十进制
CString CDushujuDlg::BinaryToDecimal(CString strBinary)
{
	int nLenth = strBinary.GetLength();
	char* Binary = new char[nLenth];
	Binary = strBinary.GetBuffer(0);
	int nDecimal = 0;
	for(int i = 0; i < nLenth; i++)
	{
		char h = Binary[nLenth - 1 - i];
		char str[1];
		str[0] = h;
		int j = atoi(str);
		for(int k = 0; k < i; k++)
		{
			j = j * 2;
		}
		nDecimal += j;
	}
	CString strDecimal;
	strDecimal.Format(_T("%d"), nDecimal);
	return strDecimal;
}