VC++ 编辑框只输入数字

void CNewEdit::OnChar(UINT nChar, UINTnRepCnt, UINT nFlags) 如下；

其它需要可以灵活定制。

void CNewEdit::OnChar(UINT nChar, UINTnRepCnt, UINT nFlags)
 {
  if(nChar==VK_BACK)//BackSpace
   CEdit::OnChar(nChar, nRepCnt,nFlags);
    //
  //Some invariable parameter for further use
  CPoint caretPt;
  caretPt=GetCaretPos ();
  caretPt.x = LOWORD (CharFromPos (caretPt));//Thefunction is the core,I'm blind to seek it for 3 daysCString str;
  int nLength;
  int nDot;
  int neE;
  double fabstr;
  GetWindowText (str);
  fabstr=fabs(atof(str));
    nLength=str.GetLength();
  nDot=str.Find(_T('.'));
  neE=max(str.Find('e'),str.Find('E'));
  
  
  
  //
  //Input 0-9,especialy 0 needs moreattention.if (isdigit(nChar))
  {
   if(nChar>'0') 
   CEdit::OnChar(nChar, nRepCnt,nFlags); else//make use of '0'
   {
    if(str.IsEmpty())
    {
     CEdit::OnChar(nChar,nRepCnt, nFlags);
     return;
    }
    
    if(str[0]=='0')
    {
       if(neE==-1)
     { 
      if(caretPt.x>1)
      {
       CEdit::OnChar(nChar,nRepCnt, nFlags);
       return;
      }
      else
       return;
     }
     else
      {
      
        if((caretPt.x-1)!=neE&& caretPt.x>1)
        {
         CEdit::OnChar(nChar,nRepCnt, nFlags);
         return;
        }
        else
         return;
       }
        
        }
     
    
    if(str[0]=='-')
     {
      if(str[1]=='0')
      {
       if(neE==-1)
       { 
        if(caretPt.x>2)
        {
         CEdit::OnChar(nChar,nRepCnt, nFlags);
         return;     
        }
       else
        return;
       }
       else
       {
        if((caretPt.x-1)!=neE&& caretPt.x>2)
        {
         CEdit::OnChar(nChar,nRepCnt, nFlags);
         return;
        }
        else
         return; 
       }
           }
   
     
     }
    
    if(str[0]>='1'&& caretPt.x>0)
    {  
     
     CEdit::OnChar(nChar,nRepCnt, nFlags);     return;
    }  
   
     }
  }
   
  
  
  
  else
   
   //
   //Determine the '-'
   if (nChar == '-')
   {
    if(!caretPt.x)
    {
     if(((nLength > 0) && (str[0]!='-')) || (nLength==0))
      CEdit::OnChar(nChar,nRepCnt, nFlags);
    }
   else
   {
    if ((str[caretPt.x-1] == 'e') || (str [caretPt.x-1] == 'E'))
     CEdit::OnChar(nChar,nRepCnt, nFlags);
   }
  }else
  
   
   //Input'e' or 'E'
   
   if ((nChar == 'e') || (nChar =='E'))
   {
    if((caretPt.x == 1) && (str[0] == '-'))
     return; if(caretPt.x)
   {
     if(neE!=-1)
      return;
    if(nDot!=-1&& caretPt.x<nDot)
     return;  CEdit::OnChar(nChar,nRepCnt, nFlags);
   }
  }else
   //
   //Input '.'
   if (nChar == '.')
   {
    if(nDot!=-1)
     return;
   
    if(neE!=-1&& caretPt.x>neE)
     return;
   CEdit::OnChar(nChar,nRepCnt, nFlags);
  }

此外如果要截取输入字符串末尾的‘0';可以利用消息WM_KILLFOCUS;

函数代码如下：

void CNewEdit::OnKillfocus()
 {
  // TODO: Add your control notification handlercode here
  CString str,tr;
  GetWindowText(str);
  int nLength;
     intnDot=-1;
  int neE;
  //double fstr;
  nLength=str.GetLength();
  
  
  
  for(int i=0;i<nLength;i++)
  {
   if(str[i]==_T('.'))
     nDot=i;
  }
  
  neE=max(str.Find(_T('e')),str.Find(_T('E')));
  
  
    
  if(nDot!=-1 && neE==-1)
   str.TrimRight(_T("0"));
  {
    int t= str.Find('.');
   
   
    if(t==str.GetLength()-1) 
    str+='0';
  }  SetWindowText(str);
 }