vs C++ 进制转换器设计

设计思路：

1. 文本框限制数字和字符输入，只接受有效数字和字符;

2. 字符串转数字、字符转数字及反向处理；

局限性：

本文只考虑了long 类型以内数据进制转换，不适用大数据

具体实现过程：

头文件：

//进制类型

enum NUMSYSTEM{ BIN, OCT, DEC, HEX };

//从当前类型转换至numSys类型
void ConvertTo(NUMSYSTEM numSys);
//从任意进制到十进制的转换
void ToDecimal(CString& strNum ,NUMSYSTEM numSys);
//从十进制到任意进制的转换
void DecimalTo(CString& strNum ,NUMSYSTEM numSys);
//去除数字前面的0
void RemoveZeroBeforeNum(CString &strNum);
//求幂函数
long Power(int aNum, int bNum);
//数字到字符
int CharToNum(TCHAR ch);
//字符到数字
TCHAR NumToChar(int nNum);

实现：

//类型转换函数
void CCalculatorDlg::ConvertTo(NUMSYSTEM numSys)
{
CString strNum;
GetDlgItemText(IDC_EDIT_NUM, strNum);
if (!strNum.IsEmpty())
{
  RemoveZeroBeforeNum(strNum);
  ToDecimal(strNum, m_numSys);
  switch (numSys)
  {
  case BIN:
   DecimalTo(strNum, BIN);
   break;
  case OCT:
   DecimalTo(strNum, OCT);
   break;
  case HEX:
   DecimalTo(strNum, HEX);
   break;
  default:
   break;
  }
}
RemoveZeroBeforeNum(strNum);
SetDlgItemText(IDC_EDIT_NUM, strNum);
}

void CCalculatorDlg::ToDecimal(CString& strNum, NUMSYSTEM numSys)
{
int nCount = strNum.GetLength();
int nBase = 0;
long nRet = 0;
switch (numSys)
{
case BIN:
  nBase = 2;
  break;
case OCT:
  nBase = 8;
  break;
case HEX:
  nBase = 16;
  break;
default:
  break;
}
if (0 == nBase)return;
while (nCount>0)
{
  nRet += CharToNum(strNum.GetAt(0))*Power(nBase, nCount - 1);
  strNum.Delete(0);
  nCount--;
}
strNum.Format(_T("%d"), nRet);
}

void CCalculatorDlg::DecimalTo(CString& strNum, NUMSYSTEM numSys)
{
long nNum = _ttoi(strNum);
strNum.Empty();
int nBase = 0;
int nRet = 0;//余数
switch (numSys)
{
case BIN:
  nBase = 2;
  break;
case OCT:
  nBase = 8;
  break;
case HEX:
  nBase = 16;
  break;
default:
  break;
}
if (0 == nBase)return;
while (nNum>1)
{
  nRet = nNum%nBase;
  nNum = nNum / nBase;
  strNum+=NumToChar(nRet);
}
strNum += NumToChar(nNum);
strNum.MakeReverse();
}

void CCalculatorDlg::RemoveZeroBeforeNum(CString &strNum)
{
while (0==strNum.Find(_T("0")))
{
strNum.Delete(0);
}
}

//求nNum的nCount次幂
long CCalculatorDlg::Power(int nNum, int nCount)
{
long nRet = 1;
while (nCount > 0)
{
nRet *= nNum;
nCount--;
}
return nRet;
}

//字符转数字
int CCalculatorDlg::CharToNum(TCHAR ch)
{
switch (ch)
{
case '0':
  return 0;
case '1':
  return 1;
case '2':
  return 2;
case '3':
  return 3;
case '4':
  return 4;
case '5':
  return 5;
case '6':
  return 6;
case '7':
  return 7;
case '8':
  return 8;
case '9':
  return 9;
case 'a':
case 'A':
  return 10;
case 'b':
case 'B':
  return 11;
case 'c':
case 'C':
  return 12;
case 'd':
case 'D':
  return 13;
case 'e':
case 'E':
  return 14;
case 'f':
case 'F':
  return 15;
default:
  return NULL;
}
}

//数字转字符
TCHAR CCalculatorDlg::NumToChar(int nNum)
{
switch (nNum)
{
case 0:
  return '0';
case 1:
  return '1';
case 2:
  return '2';
case 3:
  return '3';
case 4:
  return '4';
case 5:
  return '5';
case 6:
  return '6';
case 7:
  return '7';
case 8:
  return '8';
case 9:
  return '9';
case 10:
  return 'A';
case 11:
  return 'B';
case 12:
  return 'C';
case 13:
  return 'D';
case 14:
  return 'E';
case 15:
  return 'F';
default:
  return NULL;
}
}