用socket UDP发送接收消息怎么不自动停止

[hellengoodd]

只要客户端向服务器发送一个消息，仅仅只是一个字符，那么服务器就一直不停的recvfrom不会停止，而且得到的都是乱码
客户端：

m_mainsocketUDP=::socket(AF_INET,SOCK_DGRAM,0);
::WSAAsyncSelect(m_mainsocketUDP,m_hWnd,WM_SOCKET,FD_READ|FD_ACCEPT|FD_CLOSE);
...///代码略过
...
...LRESULT CBabyDlg::OnSocket(WPARAM  wParam, LPARAM lParam)
{
	CString gettext;
	CString cut;
	CString sqlchat;
	int npos;
	int len=sizeof(m_mainaddr);
	CTime time=CTime::GetCurrentTime();
	int hour=time.GetHour();
	int minute=time.GetMinute();
	int second=time.GetSecond();

	switch(LOWORD(lParam)){
	case FD_READ:
		FlashWindow(TRUE);
		char szgettext[1024];
		if(wParam==m_mainsocketUDP){
			recvfrom(m_mainsocketUDP,szgettext,1024,0,(sockaddr*)&(m_mainaddr),&len);
		}
...
...
...////这些代码略过，。。。

sendto(m_mainsocketUDP,"123",3,0,(sockaddr*)&m_mainaddr,sizeof(m_mainaddr));

服务器端：

m_sUDP=::socket(AF_INET,SOCK_DGRAM,0);
sockaddr_in sinaddr;
	sinaddr.sin_family=AF_INET;
	sinaddr.sin_port=htons(66);
	sinaddr.sin_addr.S_un.S_addr=INADDR_ANY;
	CString x=inet_ntoa(sinaddr.sin_addr);
	if(::bind(m_sUDP,(LPSOCKADDR)&sinaddr,sizeof(sinaddr))==SOCKET_ERROR){
		MessageBox("关联C败。。。");
	}
::WSAAsyncSelect(m_sUDP,m_hWnd,WM_SOCKET,FD_READ|FD_ACCEPT|FD_CLOSE);
...
...
...
LRESULT  CBabyDlg::OnSocket(WPARAM  wParam, LPARAM lParam) 
{
	int size=sizeof(m_laopoaddr);
	int npos;
	CString gettext;
	CString cut;
	CString sqlchat;
	CTime time=CTime::GetCurrentTime();
	int hour=time.GetHour();
	int minute=time.GetMinute();
	int second=time.GetSecond();
	switch (LOWORD(lParam))
	{
	case FD_ACCEPT:
		m_laoposocket=::accept(m_s,(sockaddr*)&m_laopoaddr,&size);
		GetDlgItemText(IDC_EDIT1,gettext);
		gettext+="\r\n\t已连接上~~";
		SetDlgItemText(IDC_EDIT1,gettext);
		m_outedit.LineScroll(m_outedit.GetLineCount());
		shake();
		m_napaccept=1;
		m_bconectOK=TRUE;
		break;
	case FD_READ:   ////这个一直出现，无限次。。。。
		FlashWindow(TRUE);
		char szgettext[1024];
		int len;
		if(wParam==m_sUDP){
			recvfrom(m_sUDP,szgettext,10,0,&m_UDPaddr,&len);
		}
		else recv(m_laoposocket,szgettext,1024,0);