MFC String: How to get the hexadecimal representation of a ... into a 'CString'?

[Gabriel Fleseriu]

Q: How to get the hexadecimal representation of a ... into a 'CString'?

A: There are two common scenarios: wanting a string containing the hexadecimal representation of some built-in type variable, like an 'int' or a 'float' or wanting the hexadecimal representation of every byte from a string.

Built-in types

The following template function can be used for built-in types:

template <class T>
CString VariableToHexString(T t)
{
  CString ret, tmp;
  for(int i = sizeof(T)-1; i>=0; --i)
  {
    unsigned char c = reinterpret_cast<unsigned char*>(&t)[i];
    tmp.Format("%02hX", c);
    ret+=tmp;
  }
  return ret;
}

AfxMessageBox(VariableToHexString<int>(12345678), 
              MB_OK,
              0);
// produces a message box containing "00 BC 61 4E"

We also provide another solution that uses Standard C++ classes.


Strings

CString StringToHexString(CString cs)
{
  CString ret, tmp;
  for(int i=0; i<cs.GetLength(); ++i)
  {
    unsigned char c = cs[i];
    tmp.Format(" %02hX", c);
    ret+=tmp;
  }
  return ret;
}

AfxMessageBox(StringToHexString("Hello"), MB_OK, 0);
// produces a message box containing "48 65 6C 6C 6F"