我正在尝试在VC ++ 6应用程序和C＃应用程序之间进行双向通信。我正在使用命名管道。在我的C ++代码中，我可以从C＃客户端读取消息，但随后服务器“死机”，我必须重新启动它。
我想要做的是让C＃应用程序连接到C ++应用程序，请求状态，然后C ++应用程序关闭并检查状态，然后返回“忙”或“空闲”。
我无法将任何内容写回C＃客户端，因为它表示连接已关闭。我已经评论过的一些事情是我已经尝试过的事情。
C ++代码（以线程开头）
UINT CNamedPipe::StartNamedPipeServer()
{
LPTSTR lpszPipename = "\\\\.\\pipe\\SAPipe";
HANDLE hPipe;
BOOL flg;
DWORD dwWrite,dwRead;
char szServerUpdate[200];
char szClientUpdate[200];
hPipe = CreateNamedPipe ( lpszPipename,
PIPE_ACCESS_DUPLEX,
PIPE_TYPE_MESSAGE |
PIPE_READMODE_MESSAGE |
PIPE_NOWAIT, //changed from nowait
PIPE_UNLIMITED_INSTANCES, // max. instances
BUFSIZE, // output buffer size
BUFSIZE, // input buffer size
PIPE_TIMEOUT, // client time-out
NULL); // no security attribute
if (hPipe == INVALID_HANDLE_VALUE)
return 0;
ConnectNamedPipe(hPipe, NULL);
while(m_bServerActive) //This seems to work well ....
{
//Read from client
flg = ReadFile(hPipe,szClientUpdate,strlen(szClientUpdate),&dwRead, NULL);
if(flg) //Read something from the client!!!!
{
CString csMsg,csTmp;
for(int i=0;i<dwRead;i++){
csTmp.Format("%c",szClientUpdate[i]);
csMsg += csTmp;
}
AfxMessageBox("Client message: " + csMsg);
strcpy( szServerUpdate,"busy");
//Write status to Client
flg = WriteFile(hPipe, szServerUpdate, strlen(szServerUpdate), &dwWrite, NULL);
EndServer();
StartServer();
}
}
return 0;
}
C＃代码：
public void ThreadStartClient(object obj)
{
// Ensure that we only start the client after the server has created the pipe
ManualResetEvent SyncClientServer = (ManualResetEvent)obj;
// Only continue after the server was created -- otherwise we just fail badly
// SyncClientServer.WaitOne();
using (NamedPipeClientStream pipeStream = new NamedPipeClientStream(".", "SAPipe"))
{
// The connect function will indefinately wait for the pipe to become available
// If that is not acceptable specify a maximum waiting time (in ms)
pipeStream.Connect();
//Write from client to server
using (StreamWriter sw = new StreamWriter(pipeStream))
{
sw.WriteLine("What's your status?");
}
//Read server reply
/*using (StreamReader sr = new StreamReader(pipeStream))
{
string temp = "";
temp = sr.ReadLine(); //Pipe is already closed here ... why?
MessageBox.Show(temp);
}*/
//pipeStream.Close();
}
}
}
答案 0 :(得分：10)
处置StreamWriter或StreamReader将关闭基础流。
因此，您的using语句将导致流关闭。
public void ThreadStartClient(object obj)
{
// Ensure that we only start the client after the server has created the pipe
ManualResetEvent SyncClientServer = (ManualResetEvent)obj;
// Only continue after the server was created -- otherwise we just fail badly
// SyncClientServer.WaitOne();
using (NamedPipeClientStream pipeStream = new NamedPipeClientStream(".", "SAPipe"))
{
// The connect function will indefinately wait for the pipe to become available
// If that is not acceptable specify a maximum waiting time (in ms)
pipeStream.Connect();
//Write from client to server
StreamWriter sw = new StreamWriter(pipeStream))
sw.WriteLine("What's your status?");
//Read server reply
StreamReader sr = new StreamReader(pipeStream)
string temp = "";
temp = sr.ReadLine(); //Pipe is already closed here ... why?
MessageBox.Show(temp);
}
}
还应该注意，因为您将流包装在using语句中，所以不需要注释掉pipeStream.Close()函数。
答案 1 :(得分：4)
好的，让它适用于我的应用....感谢Blam！
这是C ++服务器（在一个线程中运行）：
UINT CNamedPipe::StartNamedPipeServer()
{
if(!m_bServerActive)
return 0;
LPTSTR lpszPipename = "\\\\.\\pipe\\MyPipe";
HANDLE hPipe;
BOOL flg;
DWORD dwWrite,dwRead;
char szServerUpdate[200];
char szClientUpdate[200];
hPipe = CreateNamedPipe ( lpszPipename,
PIPE_ACCESS_DUPLEX,
PIPE_TYPE_MESSAGE |
PIPE_READMODE_MESSAGE |
PIPE_WAIT, //HAS TO BE THIS
PIPE_UNLIMITED_INSTANCES, // max. instances
BUFSIZE, // output buffer size
BUFSIZE, // input buffer size
PIPE_TIMEOUT, // client time-out
NULL); // no security attribute
if (hPipe == INVALID_HANDLE_VALUE)
return 0;
ConnectNamedPipe(hPipe, NULL);
strcpy( szServerUpdate,"busy");
//Write status to Client
flg = WriteFile(hPipe, szServerUpdate, strlen(szServerUpdate), &dwWrite, NULL);
EndServer();
StartServer();
return 0;
}
这是C＃客户端：
public void ThreadStartClient(object obj)
{
// Ensure that we only start the client after the server has created the pipe
ManualResetEvent SyncClientServer = (ManualResetEvent)obj;
using (NamedPipeClientStream pipeStream = new NamedPipeClientStream(".", "MyPipe", PipeDirection.InOut))
{
// The connect function will indefinately wait for the pipe to become available
// If that is not acceptable specify a maximum waiting time (in ms)
pipeStream.Connect();
if (!pipeStream.IsConnected) //It thinks it's connected but can't read anything ....
{
MessageBox.Show("Failed to connect ....");
return;
}
//Read server reply
StreamReader sr = new StreamReader(pipeStream);
char[] c = new char[200];
while (sr.Peek() >= 0)
{
sr.Read(c, 0, c.Length);
}
string s = new string(c);
MessageBox.Show(s);
}
}
我实际上并没有从客户端向服务器发送任何内容，因为我不需要......其中的关键是CreateNamedPipe（）函数中的PIPE_WAIT参数。这使服务器等待客户端连接。