接收多播数据时,我将收到的数据(u_char *)发给消息响应函数来处理,结果数据居然丢了,只剩4个字节,为什么呢?
// 接收多播消息线程
DWORD WINAPI CTestDlg::RecvMCProc(LPVOID lpParameter)
{
SOCKET sock;
HWND hwnd=((RECVPARAM*)lpParameter)->hwnd;
CString sWSIP = "192.168.1.10";
delete lpParameter; //别忘了释放内存
WSADATA wsd;
struct sockaddr_in local,remote;
SOCKET sockM;
int len = sizeof( struct sockaddr_in);
//初始化WinSock2.2
if( WSAStartup( MAKEWORD(2,2),&wsd) != 0 )
{
AfxMessageBox("函数 WSAStartup() 初始化WinSock2.2 失败/n");
return false;
}
if((sock=WSASocket(AF_INET,SOCK_DGRAM,0,NULL,0,
WSA_FLAG_MULTIPOINT_C_LEAF|WSA_FLAG_MULTIPOINT_D_LEAF|
WSA_FLAG_OVERLAPPED)) == INVALID_SOCKET)
{
AfxMessageBox("WSASocket 创建socket失败:%d/n",WSAGetLastError());
WSACleanup();
return false;
}
//将sock绑定到本机用于FA3数据交换的多播端口上。
local.sin_family = AF_INET;
local.sin_port = htons(MCASTPORT);
local.sin_addr.S_un.S_addr=inet_addr(sWSIP);
if( bind(sock ,(struct sockaddr*)&local,sizeof(local)) == SOCKET_ERROR )
{
AfxMessageBox( "绑定到本机的多播端口失败:%d /n",WSAGetLastError());
closesocket(sock);
WSACleanup();
return false;
}
//加入多播组
remote.sin_family = AF_INET;
remote.sin_port = htons(MCASTPORT);
remote.sin_addr.s_addr = inet_addr( MCASTADDR );
/* Winsock2.0*/
if(( sockM = WSAJoinLeaf(sock,(SOCKADDR*)&remote,sizeof(remote),NULL,NULL,NULL,NULL, JL_BOTH)) == INVALID_SOCKET)
{
AfxMessageBox("加入多播组失败,WSAJoinLeaf() failed:%d/n",WSAGetLastError());
closesocket(sock);
WSACleanup();
return false;
}
SOCKADDR_IN addrFrom;
u_char recvBuf[BUFSIZE];
int retval;
while(TRUE)
{
retval=recvfrom(sock,(char *)recvBuf,BUFSIZE,0,(SOCKADDR*)&addrFrom,&len);
if(SOCKET_ERROR==retval)
break;
// 这里 retval=304 ,总之比较多,是个结构体,含有很多个字符串等
//将消息内容和IP传给窗体的消息处理函数
::PostMessage(hwnd,WM_RECVMCDATA,0,(LPARAM)recvBuf);
}
}
return 0;
}
// MultiCast消息处理函数
void CTestDlg::OnRecvMCData(WPARAM wParam,LPARAM lParam)
{
u_char *MCData;
MCData= (u_char *) malloc(BUFSIZE);
MCData=(u_char *)lParam; // 地址是对的,就是数据被截断了,后面的没有了!只有4个字节!
int iDataLength=sizeof(MCData); // ==4???????
// 下面打印出来看看,这段有点乱,就是想看看数据
CString sTmpByte,sData;
for (int i=1; i < iDataLength ; i++)
{
sTmpByte.Format("%.2x ", MCData[i-1]);
sData+=sTmpByte;
if ( (i % 16) == 0) sData+="/r/n";
}
// 在文本框内显示接收到的消息,新收到的在最上一行
CString str,sTmp;
GetDlgItemText(IDC_MCText,sTmp);
str+=sData+"/r/n";
str+=sTmp;
SetDlgItemText(IDC_MCText,str);
}
// 接收多播消息线程
DWORD WINAPI CTestDlg::RecvMCProc(LPVOID lpParameter)
{
SOCKET sock;
HWND hwnd=((RECVPARAM*)lpParameter)->hwnd;
CString sWSIP = "192.168.1.10";
delete lpParameter; //别忘了释放内存
WSADATA wsd;
struct sockaddr_in local,remote;
SOCKET sockM;
int len = sizeof( struct sockaddr_in);
//初始化WinSock2.2
if( WSAStartup( MAKEWORD(2,2),&wsd) != 0 )
{
AfxMessageBox("函数 WSAStartup() 初始化WinSock2.2 失败/n");
return false;
}
if((sock=WSASocket(AF_INET,SOCK_DGRAM,0,NULL,0,
WSA_FLAG_MULTIPOINT_C_LEAF|WSA_FLAG_MULTIPOINT_D_LEAF|
WSA_FLAG_OVERLAPPED)) == INVALID_SOCKET)
{
AfxMessageBox("WSASocket 创建socket失败:%d/n",WSAGetLastError());
WSACleanup();
return false;
}
//将sock绑定到本机用于FA3数据交换的多播端口上。
local.sin_family = AF_INET;
local.sin_port = htons(MCASTPORT);
local.sin_addr.S_un.S_addr=inet_addr(sWSIP);
if( bind(sock ,(struct sockaddr*)&local,sizeof(local)) == SOCKET_ERROR )
{
AfxMessageBox( "绑定到本机的多播端口失败:%d /n",WSAGetLastError());
closesocket(sock);
WSACleanup();
return false;
}
//加入多播组
remote.sin_family = AF_INET;
remote.sin_port = htons(MCASTPORT);
remote.sin_addr.s_addr = inet_addr( MCASTADDR );
/* Winsock2.0*/
if(( sockM = WSAJoinLeaf(sock,(SOCKADDR*)&remote,sizeof(remote),NULL,NULL,NULL,NULL, JL_BOTH)) == INVALID_SOCKET)
{
AfxMessageBox("加入多播组失败,WSAJoinLeaf() failed:%d/n",WSAGetLastError());
closesocket(sock);
WSACleanup();
return false;
}
SOCKADDR_IN addrFrom;
u_char recvBuf[BUFSIZE];
int retval;
while(TRUE)
{
retval=recvfrom(sock,(char *)recvBuf,BUFSIZE,0,(SOCKADDR*)&addrFrom,&len);
if(SOCKET_ERROR==retval)
break;
// 这里 retval=304 ,总之比较多,是个结构体,含有很多个字符串等
//将消息内容和IP传给窗体的消息处理函数
::PostMessage(hwnd,WM_RECVMCDATA,0,(LPARAM)recvBuf);
}
}
return 0;
}
// MultiCast消息处理函数
void CTestDlg::OnRecvMCData(WPARAM wParam,LPARAM lParam)
{
u_char *MCData;
MCData= (u_char *) malloc(BUFSIZE);
MCData=(u_char *)lParam; // 地址是对的,就是数据被截断了,后面的没有了!只有4个字节!
int iDataLength=sizeof(MCData); // ==4???????
// 下面打印出来看看,这段有点乱,就是想看看数据
CString sTmpByte,sData;
for (int i=1; i < iDataLength ; i++)
{
sTmpByte.Format("%.2x ", MCData[i-1]);
sData+=sTmpByte;
if ( (i % 16) == 0) sData+="/r/n";
}
// 在文本框内显示接收到的消息,新收到的在最上一行
CString str,sTmp;
GetDlgItemText(IDC_MCText,sTmp);
str+=sData+"/r/n";
str+=sTmp;
SetDlgItemText(IDC_MCText,str);
}