我需要在本机命名管道和System.IO命名管道之间发送多条消息。我从一体化代码框架（IPC和RPC）获得了此通信两端的代码。
服务器：
SafePipeHandle hNamedPipe = null;
try { SECURITY_ATTRIBUTES sa = null;
sa = CreateNativePipeSecurity();
// Create the named pipe.
hNamedPipe = NativeMethod.CreateNamedPipe(
Constants.FullPipeName, // The unique pipe name.
PipeOpenMode.PIPE_ACCESS_DUPLEX, // The pipe is duplex
PipeMode.PIPE_TYPE_MESSAGE | // Message type pipe
PipeMode.PIPE_READMODE_MESSAGE | // Message-read mode
PipeMode.PIPE_WAIT, // Blocking mode is on
PIPE_UNLIMITED_INSTANCES, // Max server instances
1024, // Output buffer size
1024, // Input buffer size
NMPWAIT_USE_DEFAULT_WAIT, // Time-out interval
sa // Pipe security attributes
);
if (hNamedPipe.IsInvalid)
{
throw new Win32Exception();
}
Console.WriteLine("The named pipe ({0}) is created.", Constants.FullPipeName);
// Wait for the client to connect.
Console.WriteLine("Waiting for the client's connection...");
if (!NativeMethod.ConnectNamedPipe(hNamedPipe, IntPtr.Zero))
{
if (Marshal.GetLastWin32Error() != ERROR_PIPE_CONNECTED)
{
throw new Win32Exception();
}
}
Console.WriteLine("Client is connected.");
//
// Receive a request from client.
//
string message;
bool finishRead = false;
do
{
byte[] bRequest = new byte[1024];
int cbRequest = bRequest.Length, cbRead;
finishRead = NativeMethod.ReadFile(
hNamedPipe, // Handle of the pipe
bRequest, // Buffer to receive data
cbRequest, // Size of buffer in bytes
out cbRead, // Number of bytes read
IntPtr.Zero // Not overlapped
);
if (!finishRead &&
Marshal.GetLastWin32Error() != ERROR_MORE_DATA)
{
throw new Win32Exception();
}
// Unicode-encode the received byte array and trim all the
// '\0' characters at the end.
message = Encoding.Unicode.GetString(bRequest).TrimEnd('\0');
Console.WriteLine("Receive {0} bytes from client: \"{1}\"", cbRead, message);
}
while (!finishRead); // Repeat loop if ERROR_MORE_DATA
//
// Send a response from server to client.
//
message = "Goodbye\0";
byte[] bResponse = Encoding.Unicode.GetBytes(message);
int cbResponse = bResponse.Length, cbWritten;
if (!NativeMethod.WriteFile(
hNamedPipe, // Handle of the pipe
bResponse, // Message to be written
cbResponse, // Number of bytes to write
out cbWritten, // Number of bytes written
IntPtr.Zero // Not overlapped
))
{
throw new Win32Exception();
}
Console.WriteLine("Send {0} bytes to client: \"{1}\"",
cbWritten, message.TrimEnd('\0'));
// Flush the pipe to allow the client to read the pipe's contents
// before disconnecting. Then disconnect the client's connection.
NativeMethod.FlushFileBuffers(hNamedPipe);
NativeMethod.DisconnectNamedPipe(hNamedPipe);
} catch（Exception ex）{ Console.WriteLine（“服务器抛出错误：{0}”，ex.Message）; } 最后 { if（hNamedPipe！= null） { hNamedPipe.Close（）; hNamedPipe = null; } }
客户端：
NamedPipeClientStream pipeClient = null;
try
{
// Try to open the named pipe identified by the pipe name.
pipeClient = new NamedPipeClientStream(
".", // The server name
Constants.PipeName, // The unique pipe name
PipeDirection.InOut, // The pipe is duplex
PipeOptions.None // No additional parameters
);
pipeClient.Connect(5000);
MessageBox.Show(
string.Format( "The named pipe ({0}) is connected.", Constants.PipeName )
);
pipeClient.ReadMode = PipeTransmissionMode.Message;
//
// Send a request from client to server
//
for ( int i = 0; i < 2; i++ ) {
string message = "hello my pipe dream\0";
byte[] bRequest = Encoding.Unicode.GetBytes( message );
int cbRequest = bRequest.Length;
pipeClient.Write( bRequest, 0, cbRequest );
MessageBox.Show(
string.Format( "Send {0} bytes to server: \"{1}\"", cbRequest, message.TrimEnd( '\0' ) )
);
}
//
// Receive a response from server.
//
do
{
byte[] bResponse = new byte[1024];
int cbResponse = bResponse.Length, cbRead;
cbRead = pipeClient.Read(bResponse, 0, cbResponse);
// Unicode-encode the received byte array and trim all the
// '\0' characters at the end.
string message = Encoding.Unicode.GetString(bResponse).TrimEnd('\0');
Console.WriteLine("Receive {0} bytes from server: \"{1}\"",
cbRead, message);
}
while (!pipeClient.IsMessageComplete);
}
catch (Exception ex)
{
new ErrorDialog( ex ).ShowDialog();
}
finally
{
// Close the pipe.
if (pipeClient != null)
{
pipeClient.Close();
pipeClient = null;
}
}
}
正如您在上面的“从客户端向服务器发送请求”部分中的for循环中所看到的，我正在尝试弄清楚如何向服务器发送多条消息。我看到服务器代码循环直到NativeMethod.ReadFile（）方法返回true。我的问题是它总是在读取第一条消息后返回true，并忽略第二条消息所以我的问题，具体来说，我需要在客户端代码中做什么，以便此方法返回false，然后它将获得第二条消息。
答案 0 :(得分：1)
除了将所有“消息”发送到管道中之外，客户端无法做任何事情。这是因为，在消息模式下，消息由发送方的写入调用完成分隔，并且您的服务器代码显式只读取一条消息（在管道消息模式意义上）。请参阅CreateNamedPipe和ReadFile API文档：
数据作为a写入管道 消息流。管道对待 每次写入时写入的字节数 作为信息单位的操作。
如果正在读入命名管道 消息模式和下一条消息是 比nNumberOfBytesToRead长 参数指定，ReadFile返回 FALSE和GetLastError返回 ERROR_MORE_DATA。其余部分 消息可以由后续读取 调用ReadFile或 PeekNamedPipefunction。
使用多条消息的可能方法是：
答案 1 :(得分：0)
谢谢Chris，我指的是文档。我提出了你的回答，因为你所引用的引言让我得到了我正在寻找的答案。
事实证明，我对服务器代码的“从客户端接收请求”部分中的do / while循环感到困惑。也就是说，它看起来像是从客户端检索多条消息。但实际上，它正在检索单个消息的连续部分。我更新了该代码部分如下。
// Receive a request from client.
string message = string.Empty;
bool finishRead = false;
do
{
byte[] bRequest = new byte[1024];
int cbRequest = bRequest.Length, cbRead;
finishRead = NativeMethod.ReadFile(
hNamedPipe, // Handle of the pipe
bRequest, // Buffer to receive data
cbRequest, // Size of buffer in bytes
out cbRead, // Number of bytes read
IntPtr.Zero // Not overlapped
);
if (!finishRead &&
Marshal.GetLastWin32Error() != ERROR_MORE_DATA)
{
throw new Win32Exception();
}
// Unicode-encode the received byte array and trim all the
// '\0' characters at the end.
message += Encoding.Unicode.GetString(bRequest).TrimEnd('\0');
}
while (!finishRead); // Repeat loop if ERROR_MORE_DATA
Console.WriteLine( "Message received from client: \"{0}\"", message );
至于在客户端对服务器的请求中划分多个“消息”，我可能只会使用换行符。