gethostbyname

Question

调用gethostbyname返回错误WSAHOST_NOT_FOUND怎么解决?

Answer 1

WSAHOST_NOT_FOUND
 Authoritative answer host not found.
 

Answer 2

就是没有找到，DNS 没有返回正确的解析结果

Answer 3

正常代码：
void CChatDlg::OnBtnSend() 
{
// TODO: Add your control notification handler code here
DWORD  dwIP;
CString  strSend;
WSABUF   wsabuf;
DWORD   dwSend;
int   len;
SOCKADDR_IN   addrTo;
((CIPAddressCtrl*)GetDlgItem(IDC_IPADDRESS1))->GetAddress(dwIP);
addrTo.sin_addr.S_un.S_addr=htonl(dwIP);
addrTo.sin_family=AF_INET;
addrTo.sin_port=htons(6000); GetDlgItemText(IDC_EDIT_SEND,strSend);
len=strSend.GetLength();
wsabuf.buf=strSend.GetBuffer(len);
wsabuf.len=len+1; SetDlgItemText(IDC_EDIT_SEND,""); if(SOCKET_ERROR==WSASendTo(m_socket,&wsabuf,1,&dwSend,0,(SOCKADDR*)&addrTo,sizeof(SOCKADDR),NULL,NULL))
{
MessageBox("发送数据失败！");
return;
}
}
加了if-else语句后的错误代码：
void CChatDlg::OnBtnSend() 
{
// TODO: Add your control notification handler code here
DWORD  dwIP;
CString  strSend;
WSABUF   wsabuf;
DWORD   dwSend;
int len;
SOCKADDR_IN   addrTo;
CString   strHostName;
HOSTENT  *pHost;
if(GetDlgItemText(IDC_EDIT_HOSTNAME,strHostName),strHostName=="")
{
((CIPAddressCtrl*)GetDlgItem(IDC_IPADDRESS1))->GetAddress(dwIP);
    addrTo.sin_addr.S_un.S_addr=htonl(dwIP); }
else
{
pHost=gethostbyname(strHostName);
int  nihao=WSAGetLastError();
CString  str;
str.Format("%d",nihao);


        if(WSAHOST_NOT_FOUND==nihao)
{
MessageBox("是的1");
}
if(WSATRY_AGAIN==nihao)
{
MessageBox("是的2");
}
if(WSANO_RECOVERY==nihao)
{
MessageBox("是的3");
}
 
addrTo.sin_addr.S_un.S_addr=*((DWORD*)pHost->h_addr_list[0]);
}
addrTo.sin_family=AF_INET;
addrTo.sin_port=htons(6000); GetDlgItemText(IDC_EDIT_SEND,strSend);
len=strSend.GetLength();
wsabuf.buf=strSend.GetBuffer(len);
wsabuf.len=len+1; SetDlgItemText(IDC_EDIT_SEND,""); if(SOCKET_ERROR==WSASendTo(m_socket,&wsabuf,1,&dwSend,0,(SOCKADDR*)&addrTo,sizeof(SOCKADDR),NULL,NULL))
{
MessageBox("发送数据失败！");
return;
}

}

Answer 4

先获得本机主机名，pHost=gethostbyname(strHostName);
strHostName应该是主机名吧，你好像是写进去的 
用char    HostName[100];
gethostname(HostName, sizeof(HostName));// 获得本机主机名.
试试不知有没有用对你