纯虚函数，虚析构函数

if(!SUCCEEDED(CoInitialize(NULL))){
//cout<<"error on initialize"<<endl;
AfxMessageBox(_T("error on CoInitialize"),MB_OK,0);
return -1;
}//SUCCEEDED(CoInitialize(NULL) 必须这样判断

releasedispatch而不是detachdispatch

void CancelBlockingCall( );
This function cancels any outstanding blocking operation for this socket. The original blocking call will terminate as soon as possible with the error WSAEINTR.
In the case of a blocking Connect operation, the Windows Sockets implementation will terminate the blocking call as soon as possible, but it may not be possible for the socket resources to be released until the connection has completed (and then been reset) or timed out. This is likely to be noticeable only if the application immediately tries to open a new socket (if no sockets are available), or to connect to the same peer.
Canceling any operation other than Accept can leave the socket in an indeterminate state. If an application cancels a blocking operation on a socket, the only operation that the application can depend on being able to perform on the socket is a call to Close, although other operations may work on some Windows Sockets implementations. If you desire maximum portability for your application, you must be careful not to depend on performing operations after a cancel.
For more information, see Windows Sockets: Using Sockets with Archives.

cvtres LNK1123 COFF
按网络上说是直接把embad置否即可，如果还出现这种情况，搞了半天按下面方法搞定：
搜索C盘和VS安装盘里面的所有文件，找出其中的"cvtres.exe"
对比C:\program file(x86)\microsoft visual studio 10.0\vc 目录下(包括子文件夹)里的所有cvtres.exe，右键属性看版本。
然后再找C:\Windows\Microsoft.NET\Framework 和 Framework64下的两个cvtres.exe，同样看版本。
上述两次看版本之后看下哪个是最新的，把旧的删除掉就可以了。。。