使用命名管道在winform程序中输出windows service运行状态

最近的工作需要写一个windows服务，定时执行任务。众所周知windows service程序是没有用户界面的，而有时候是需要知道服务正在做什么的。怎么办呢？可否用winform程序显示服务执行状态呢？如何让winform取到windows service进程的消息呢？这个场景用命名管道不是正合适吗？是的，命名管道正合适。

先来想下实现的思路：

Windows服务程序要声明NamedPipeServerStream对象实例，然后等待winform程序的NamePipeClientStream实例连接到管道；连接到之后windows服务程序将其执行状态通过命名管道输出给winforms程序。

Winform程序可以随时断开管道连接，断开之后windows服务程序要继续等待winform程序再次连接到管道，连接之后可以继续输出其执行状态。另外winform程序可以在局域网的任何一台机器上连接到服务器上的windows服务程序，以方便观察服务的执行状态

思路就是这个样子了，下面我们先看下Windows服务程序中的关键实现：

public class ServiceStatusPublishManager
{
private const int MAX_LENGTH = 200;

private List<string> _msgs;

private ManagerImple _managerImp;

protected ServiceStatusPublishManager()
{
_managerImp = new ManagerImple(this);
_msgs = new List<string>();
}

static public readonly ServiceStatusPublishManager Instance = new ServiceStatusPublishManager();

public void AppendMessage(string msg)
{
lock (this) _msgs.Add(msg);

if (_msgs.Count > MAX_LENGTH)
{
lock (this)
{
_msgs.RemoveAt(0);
if (_managerImp._msgIndex == _msgs.Count) _managerImp._msgIndex -= 2;
}
}
}

class ManagerImple
{
private ServiceStatusPublishManager _trace;

private Thread _thread;

public ManagerImple(ServiceStatusPublishManager trace)
{
_trace = trace;
_thread = new Thread(WriteServiceStatus);
_thread.Start();
}

public int _msgIndex = 0;

private void WriteServiceStatus(object stats)
{
while (true)
{
try
{
using (NamedPipeServerStream serverStream = new NamedPipeServerStream("ServiceStatusPipe", PipeDirection.InOut, 10, PipeTransmissionMode.Message))
{
serverStream.WaitForConnection();

while (serverStream.IsConnected)
{
bool writeSomeMessage = false;
while (_msgIndex < _trace._msgs.Count)
{
string msg = _trace._msgs[_msgIndex];
byte[] bytes = Encoding.UTF8.GetBytes(msg);
serverStream.Write(bytes, 0, bytes.Length);
serverStream.Flush();
_msgIndex++;
writeSomeMessage = true;
}

if (!writeSomeMessage)
{
byte[] bytes = Encoding.UTF8.GetBytes("无消息输出,MsgIndex = " + _msgIndex + ",消息总数 = " + _trace._msgs.Count);

serverStream.Write(bytes, 0, bytes.Length);
serverStream.Flush();
Thread.Sleep(1000 * 10);
}
Thread.Sleep(1000);
}

}
}
catch (Exception ex)
{
}
}

}
}
}

Winform程序中关键实现部分：

void RefreshStatus(object stats)
{
try
{
using (System.IO.Pipes.NamedPipeClientStream stream = new System.IO.Pipes.NamedPipeClientStream(ServerName, "ServiceStatusPipe"))
{
stream.Connect(3000);
stream.ReadMode = System.IO.Pipes.PipeTransmissionMode.Message;

byte[] bytes = new byte[16];
char[] chars = new char[16];
int read;
do
{
string msg = string.Empty;

do
{
read = stream.Read(bytes, 0, bytes.Length);
if (read > 0)
{
int getCharCount = _decoder.GetChars(bytes, 0, read, chars, 0);
msg += new string(chars, 0, getCharCount);
}
} while (!stream.IsMessageComplete);

if (!string.IsNullOrEmpty(msg))
{
AddMsg(msg);
}

_decoder.Reset();

Thread.Sleep(20);
} while (!_closing);
}
}
catch (Exception ex)
{
AddMsg("异常：" + ex.Message);
Thread.Sleep(1000);

RefreshStatus(null);
}
}

源码下载

前一段时间写过两篇命名管道方面的文章：

使用管道在进程间通信 （System.IO.Pipes使用）

System.IO系列：局域网内多线程使用命名管道在进程之间通信实例