CEdit控件对输入参数的控制，包括右键面板及快捷键的处理

#include "stdafx.h"
#include "NumEdit.h"

#define VK_CTRL_X          0x18                   
#define VK_CTRL_C          0x03
#define VK_CTRL_V          0x16
// CNumEdit

IMPLEMENT_DYNAMIC(CNumEdit, CEdit)

CNumEdit::CNumEdit()
{
 m_strValue = _T("");
 m_nMaxValue = 0;
 m_nMinValue = 0;
}

CNumEdit::~CNumEdit()
{
}

BEGIN_MESSAGE_MAP(CNumEdit, CEdit)
 ON_WM_CHAR()
END_MESSAGE_MAP()

void CNumEdit::OnChar(UINT nChar, UINT nRepCnt, UINT nFlags)
{
  int nCurserPos = 0;
 if ((nChar>='0'&&nChar<='9')|| VK_BACK==nChar)
 { 
  GetWindowText( m_strValue );
  CString str;
  int nLen = 0;
  int nBegin = 0;
  int nEnd = 0; 
  GetSel( nBegin, nEnd );
  nLen = m_strValue.GetLength();
  if( VK_BACK == nChar )
  {