我有两项服务。 1-客户端2-服务器。两个服务都通过套接字进行通信 客户端包含文件系统观察程序。只要文件系统观察程序检测到指定文件夹中的新文件，它就会建立与服务器的连接并将文件发送到服务器。 服务器侦听特定端口并接受请求并接收文件并将详细信息保存到DB。然后将成功/错误消息发送给客户端。
整个系统第一次正常运行。但是当filesystemwatcher获取第二个文件时，应用程序会生成异常“进程无法访问该文件。它正被另一个进程使用”。再次调试服务时，没有异常。无法确定问题的确切原因。
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客户代码：
namespace WindowsService1
{
public partial class Client : ServiceBase
{
string hostIPAddress = string.Empty;
string processedFilePath = string.Empty;
int hostPort;
Socket socketClient;
IPEndPoint remoteEndPoint;
FileStream fs;
public PCMParserClient()
{
InitializeComponent();
}
protected override void OnStart(string[] args)
{
hostIPAddress = ConfigurationManager.AppSettings["HostIP"];
hostPort = int.Parse(ConfigurationManager.AppSettings["HostPort"]);
//File system watcher
FsWatcher.Path = ConfigurationManager.AppSettings["FileWatcherPath"];
processedFilePath = ConfigurationManager.AppSettings["ProcessedFilePath"];
}
protected override void OnStop()
{
}
private void FsWatcher_Created(object sender, System.IO.FileSystemEventArgs e)
{
try
{
socketClient = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
IPAddress remoteIPAddress = IPAddress.Parse(hostIPAddress);
remoteEndPoint = new IPEndPoint(remoteIPAddress, hostPort);
//Establish the connection to server
socketClient.Connect(remoteEndPoint);
EventLog.WriteEntry(e.Name+"before");
**//the below line generates teh exception for 2nd time onwards**
using (fs = new FileStream(e.FullPath, FileMode.Open, FileAccess.Read, FileShare.Read))
{
EventLog.WriteEntry("1");
//Convert the file name in form of byte
byte[] fileNameByte = Encoding.ASCII.GetBytes(e.Name);
EventLog.WriteEntry(e.Name);
//4- to store the filename length(as int - 4bytes)
//8- to store the file content length(as long take 8 bytes)
int totalLength = 4 + fileNameByte.Length + 8;
//Clientdata[] reprents the data to sent to the server
//which represent the file details
byte[] clientData = new byte[totalLength];
byte[] fileNameLength = BitConverter.GetBytes(fileNameByte.Length);
byte[] fileContentLength = BitConverter.GetBytes(fs.Length);
//Copy all the data ClientData array
fileNameLength.CopyTo(clientData, 0);
fileNameByte.CopyTo(clientData, 4);
fileContentLength.CopyTo(clientData, 4 + fileNameByte.Length);
//Send the data to server
socketClient.Send(clientData);
int byteRead = 0;
int bytesToRead = (int)fs.Length;
while (bytesToRead > 0)
{
byte[] data = new Byte[1500];
byteRead = bytesToRead > 1500 ? 1500 : bytesToRead;
int n = fs.Read(data, 0, byteRead);
//Send the data to server
socketClient.Send(data);
bytesToRead -= n;
}
fs.Flush();
//fs.Close();
//fs.Dispose();
}
//Code block to get the success/failure message from server
byte[] message = new byte[5];
int msg = socketClient.Receive(message);
else if (Encoding.ASCII.GetString(message).Contains("Error"))
{
throw new Exception("Error occured while processing the file " + e.Name);
}
}
catch (SocketException ex)
{
ExceptionLogger.LogException(ex);
}
catch (IOException ex)
{
ExceptionLogger.LogException(ex);
}
catch (Exception ex)
{
ExceptionLogger.LogException(ex);
}
finally
{
if (socketClient != null && socketClient.Connected)
{
socketClient.Close();
}
}
}
}
}
服务器代码：
namespace PCMParserService
{
public partial class ParserServer : ServiceBase
{
Socket serverSocket = null;
public Timer timer1;
IPEndPoint ipEndPoint;
public HL7ParserService()
{
InitializeComponent();
timer1 = new Timer(1000);
timer1.Elapsed += new ElapsedEventHandler(timer1_Elapsed);
}
void timer1_Elapsed(object sender, ElapsedEventArgs e)
{
Socket handler = null;
try
{
// The program is suspended while waiting for an incoming connection.
// This is a synchronous TCP application
handler = serverSocket.Accept();
byte[] fileDetails = new byte[1500];
//Recieve the file details
handler.Receive(fileDetails);
int fileNameLength = BitConverter.ToInt32(fileDetails, 0);
string fileName = Encoding.ASCII.GetString(fileDetails, 4, fileNameLength);
EventLog.WriteEntry(fileNameLength.ToString(), System.Diagnostics.EventLogEntryType.Information);
int fileLength = BitConverter.ToInt32(fileDetails, 4 + fileNameLength);
filePath = ConfigurationManager.AppSettings["ProcessedDirectory"];
FileStream fs = new FileStream(filePath + fileName, FileMode.Create, FileAccess.Write);
int byteRead = 0;
while (byteRead < fileLength)
{
byte[] data = new Byte[1500];
//Recieve the data and write to the file
int r = handler.Receive(data);
fs.Write(data, 0, r);
byteRead += r;
}
fs.Flush();
fs.Close();
fs.Dispose();
//-Code to Parse text file and save to db
FileStream fileStream = new FileStream(filePath + fileName, FileMode.Open, FileAccess.Read);
StreamReader sr = new StreamReader(fileStream);
///Code
fileStream.Close();
fileStream.Dispose();
sr.Close();
sbMessage.Append("</Message>");
saveFileDetails(sbMessage.ToString());
//-- End of File Parsing code
handler.Send(Encoding.ASCII.GetBytes("Done"));
}
catch (SocketException ex)
{
ExceptionLogger.LogException(ex, "Error occured while processing the file + " + filePath);
handler.Send(Encoding.ASCII.GetBytes("Error"));
}
catch (IOException ex)
{
ExceptionLogger.LogException(ex, "Error occured while processing the file + " + filePath);
handler.Send(Encoding.ASCII.GetBytes("Error"));
}
catch (SqlException ex)
{
ExceptionLogger.LogException(ex, "Error occured while processing the file + " + filePath);
handler.Send(Encoding.ASCII.GetBytes("Error"));
}
catch (Exception ex)
{
ExceptionLogger.LogException(ex, "Error occured while processing the file + " + filePath);
handler.Send(Encoding.ASCII.GetBytes("Error"));
}
}
protected override void OnStart(string[] args)
{
try
{
//The port on which the server listens
ipEndPoint = new IPEndPoint(IPAddress.Any, 8030);
//Defines the kind of socket we want :TCP
serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
//Bind the socket to the local end point(associate the socket to local end point)
serverSocket.Bind(ipEndPoint);
//listen for incoming connection attempt
// Start listening, only allow 100 connection to queue at the same time
serverSocket.Listen(100);
timer1.Start();
}
catch (SocketException ex)
{
ExceptionLogger.LogException(ex, string.Empty);
}
catch (Exception ex)
{
ExceptionLogger.LogException(ex, string.Empty);
}
}
protected override void OnStop()
{
timer1.Stop();
}
protected override void OnPause()
{
timer1.Stop();
}
protected override void OnContinue()
{
timer1.Start();
}
protected override void OnShutdown()
{
timer1.Stop();
}
}
}
答案 0 :(得分：2)
这通常是由于当FileSystemWatcher通知您监视目录中有新文件时，写入文件的过程尚未完成写入文件，从而释放文件。
缓解此问题的选项包括：
在调试/测试期间，您通常不会看到此问题，因为您要么手动将文件复制到监视目录中，要么慢慢地逐步执行代码，以便在尝试打开文件之前完成文件的编写
答案 1 :(得分：0)
另外，要注意的另一件事是你可以打开一个文件，指明多个对象对它的访问类型（在你的情况下可能会有所不同）。
所以，而不是写作：
FileStream fileStream = new FileStream(filePath + fileName,
FileMode.Open,
FileAccess.Read);
您可以尝试添加FileShare选项：
FileStream fileStream = new FileStream(filePath + filename,
FileMode.Open,
FileAccess.Read,
FileShare.Read))
通过指定适当的FileShare标志，您可以访问该文件而无需等待它关闭。例如，在上面的行中，FileShare.Read：
允许随后打开文件进行阅读。如果未指定此标志，则在文件关闭之前，任何打开文件以供读取（通过此进程或其他进程）的请求都将失败。