vc+ socket客户端示例程序

#define PRE_AGREED_PORT 8686
#define RECV_BUFFER_SIZE 4096

BOOL CYourClientClass::GetFileFromRemoteSender(CString strIP,
CString fName)
{
AfxSocketInit(NULL);
CSocket sockClient;
sockClient.Create();
// PRE_AGREED_PORT 是 #define 8686
sockClient.Connect( strIP, PRE_AGREED_PORT );

//连接服务器



BOOL bRet = TRUE;

int dataLength, cbBytesRet, cbLeftToReceive;
BYTE* recdData = NULL;

CFile destFile;
CFileException fe;
BOOL bFileIsOpen = FALSE;

//打开或创建文件

if( !( bFileIsOpen = destFile.Open( fName, CFile::modeCreate |
CFile::modeWrite | CFile::typeBinary, &fe ) ) )
{
TCHAR strCause[256];
fe.GetErrorMessage( strCause, 255 );
TRACE( "GetFileFromRemoteSender encountered
an error while opening the local file\n"
"\tFile name = %s\n\tCause = %s\n\tm_cause = %d\n\tm_IOsError = %d\n",
fe.m_strFileName, strCause, fe.m_cause, fe.m_lOsError );

//在这里处理错误

bRet = FALSE;
goto PreReturnCleanup;
}


//得到文件的大小
cbLeftToReceive = sizeof( dataLength );

do
{
BYTE* bp = (BYTE*)(&dataLength) + sizeof(dataLength) - cbLeftToReceive;
cbBytesRet = sockClient.Receive( bp, cbLeftToReceive );


if ( cbBytesRet == SOCKET_ERROR || cbBytesRet == 0 )
{
int iErr = ::GetLastError();
TRACE( "GetFileFromRemoteSite returned
a socket error while getting file length\n"
"\tNumber of Bytes received (zero means connection was closed) = %d\n"
"\tGetLastError = %d\n", cbBytesRet, iErr );

//处理错误

bRet = FALSE;
goto PreReturnCleanup;
}


cbLeftToReceive -= cbBytesRet;

}
while ( cbLeftToReceive > 0 );

dataLength = ntohl( dataLength );



recdData = new byte[RECV_BUFFER_SIZE];
cbLeftToReceive = dataLength;

do
{
int iiGet, iiRecd;

iiGet = (cbLeftToReceivecbLeftToReceive : RECV_BUFFER_SIZE ;
iiRecd = sockClient.Receive( recdData, iiGet );


if ( iiRecd == SOCKET_ERROR || iiRecd == 0 )
{
int iErr = ::GetLastError();
TRACE( "GetFileFromRemoteSite returned a socket error
while getting chunked file data\n"
"\tNumber of Bytes received (zero means connection was closed) = %d\n"
"\tGetLastError = %d\n", iiRecd, iErr );

//要在这里处理错误

bRet = FALSE;
goto PreReturnCleanup;
}


destFile.Write( recdData, iiRecd); // 写入数据
cbLeftToReceive -= iiRecd;

}
while ( cbLeftToReceive > 0 );

PreReturnCleanup: // 入口点

delete[] recdData;

if ( bFileIsOpen )
destFile.Close();


sockClient.Close();

return bRet;
}