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我有一個C＃windows窗體應用程序，它通過COM端口與USB加密狗進行通信。我使用.Net 2.0中的SerialPort類進行通信，並且串行端口對象在應用程序的整個生命週期中都處於打開狀態。應用程序向設備發送命令，也可以從設備接收未經請求的數據。在.Net 2.0中關閉SerialPort時發生ObjectDisposedException異常
當窗體關閉時發生我的問題 - 當嘗試關閉COM端口時，我得到（隨機，不幸）ObjectDisposedException。下面是Windows的堆棧跟蹤：
System.ObjectDisposedException was unhandled
Message=Safe handle has been closed
Source=System
ObjectName=""
StackTrace:
at Microsoft.Win32.UnsafeNativeMethods.SetCommMask(SafeFileHandle hFile, Int32 dwEvtMask)
at System.IO.Ports.SerialStream.Dispose(Boolean disposing)
at System.IO.Ports.SerialStream.Finalize()
InnerException:
我從人有類似問題發現帖子，並試圖解決方法[這裏] [1]
[1]：http://zachsaw.blogspot.com/2010/07/net-serialport-woes.html儘管這是一個IOException和並沒有阻止這個問題。
我的Close（）方法的代碼如下：
public void Close()
{
try
{
Console.WriteLine("******ComPort.Close - baseStream.Close*******");
baseStream.Close();
}
catch (Exception ex)
{
Console.WriteLine("******ComPort.Close baseStream.Close raised exception: " + ex + "*******");
}
try
{
_onDataReceived = null;
Console.WriteLine("******ComPort.Close - _serialPort.Close*******");
_serialPort.Close();
}
catch (Exception ex)
{
Console.WriteLine("******ComPort.Close - _serialPort.Close raised exception: " + ex + "*******");
}
}
我的記錄顯示，執行從來沒有超越試圖關閉一個串口的BaseStream（這是第一try塊），所以我刪除此試驗但異常仍然是週期性拋出 - 第二個try塊中的日誌出現，然後發生異常。 catch塊沒有捕捉到異常。
任何想法？
更新 - 加滿級：
namespace My.Utilities
{
public interface ISerialPortObserver
{
void SerialPortWriteException();
}
internal class ComPort : ISerialPort
{
private readonly ISerialPortObserver _observer;
readonly SerialPort _serialPort;
private DataReceivedDelegate _onDataReceived;
public event DataReceivedDelegate OnDataReceived
{
add { lock (_dataReceivedLocker) { _onDataReceived += value; } }
remove { lock (_dataReceivedLocker) { _onDataReceived -= value; } }
}
private readonly object _dataReceivedLocker = new object();
private readonly object _locker = new object();
internal ComPort()
{
_serialPort = new SerialPort { ReadTimeout = 10, WriteTimeout = 100, DtrEnable = true };
_serialPort.DataReceived += DataReceived;
}
internal ComPort(ISerialPortObserver observer) : this()
{
_observer = observer;
}
private void DataReceived(object sender, SerialDataReceivedEventArgs e)
{
DataReceivedDelegate temp = null;
lock (_locker)
{
lock (_dataReceivedLocker)
{
temp = _onDataReceived;
}
string dataReceived = string.Empty;
var sp = (SerialPort) sender;
try
{
dataReceived = sp.ReadExisting();
}
catch (Exception ex)
{
Logger.Log(TraceLevel.Error, "ComPort.DataReceived raised exception: " + ex);
}
if (null != temp && string.Empty != dataReceived)
{
try
{
temp(dataReceived, TickProvider.GetTickCount());
}
catch (Exception ex)
{
Logger.Log(TraceLevel.Error, "ComPort.DataReceived raised exception calling handler: " + ex);
}
}
}
}
public string Port
{
set
{
try
{
_serialPort.PortName = value;
}
catch (Exception ex)
{
Logger.Log(TraceLevel.Error, "ComPort.Port raised exception: " + ex);
}
}
}
private System.IO.Stream comPortStream = null;
public bool Open()
{
SetupSerialPortWithWorkaround();
try
{
_serialPort.Open();
comPortStream = _serialPort.BaseStream;
return true;
}
catch (Exception ex)
{
Logger.Log(TraceLevel.Warning, "ComPort.Open raised exception: " + ex);
return false;
}
}
public bool IsOpen
{
get
{
SetupSerialPortWithWorkaround();
try
{
return _serialPort.IsOpen;
}
catch(Exception ex)
{
Logger.Log(TraceLevel.Error, "ComPort.IsOpen raised exception: " + ex);
}
return false;
}
}
internal virtual void SetupSerialPortWithWorkaround()
{
try
{
//http://zachsaw.blogspot.com/2010/07/net-serialport-woes.html
// This class is meant to fix the problem in .Net that is causing the ObjectDisposedException.
SerialPortFixer.Execute(_serialPort.PortName);
}
catch (Exception e)
{
Logger.Log(TraceLevel.Info, "Work around for .Net SerialPort object disposed exception failed with : " + e + " Will still attempt open port as normal");
}
}
public void Close()
{
try
{
comPortStream.Close();
}
catch (Exception ex)
{
Logger.Log(TraceLevel.Error, "ComPortStream.Close raised exception: " + ex);
}
try
{
_onDataReceived = null;
_serialPort.Close();
}
catch (Exception ex)
{
Logger.Log(TraceLevel.Error, "ComPort.Close raised exception: " + ex);
}
}
public void WriteData(string aData, DataReceivedDelegate handler)
{
try
{
OnDataReceived += handler;
_serialPort.Write(aData + "\r\n");
}
catch (Exception ex)
{
Logger.Log(TraceLevel.Error, "ComPort.WriteData raised exception: " + ex);
if (null != _observer)
{
_observer.SerialPortWriteException();
}
}
}
}
}
你似乎是「泄漏」（不關閉或處置）的'SerialStream'類的實例（因爲'SerialStream.Finalize'被稱爲在你的堆棧跟蹤），我建議，這是*一個*問題，但是要確定這與您目前的問題有什麼關係需要更多信息。 –
感謝您的回覆。哪些信息將有助於查明問題？ – barry
包含上面的'Close'方法的整個類將有所幫助。 –