我有一个奇怪的问题。我有一个程序，如果应用程序捕获异常，它会向我发送一封电子邮件。通过这些异常处理，我的应用程序将向用户显示一个消息框，表明存在错误。但我的问题是，我的用户从未从应用程序中收到错误消息，但我总是收到一封电子邮件，该程序捕获了异常。为了向您展示，这是我的MySqlClass，用于处理程序的sql事务：
/// <summary>
/// Disposable class to handle database transactions
/// Error logging use can be found in TechSol_Skeet => Error.cs
/// </summary>
public class DbHelper : IDisposable
{
#region Properties
//public properties need to be set before opening the connection
public bool UseStored = false;
public bool UseTransaction = false;
public string ConnectionString { get; set; }
public string Query { get; set; }
private MySqlConnection _connection { get; set; }
private MySqlCommand _command { get; set; }
private MySqlTransaction _transaction;
#endregion
public DbHelper()
{
}
#region IDisposable Members
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
protected void Dispose(bool isDisposing)
{
if (isDisposing)
{
if (_command != null) _command.Dispose();
if (_connection != null) _connection.Dispose();
if (_transaction != null) _transaction.Dispose();
}
Query = null;
ConnectionString = null;
}
~DbHelper()
{
Dispose(false);
}
#endregion IDisposable Members
/// <summary>
/// Opens the connection, make sure to set the public properties before calling this out
/// If uses transaction, BeginTransaction
/// </summary>
public void Open()
{
try
{
_connection = new MySqlConnection(ConnectionString);
_connection.Open();
if (UseTransaction)
{
_transaction = _connection.BeginTransaction();
}
_command = new MySqlCommand
{
Connection = _connection,
CommandType = UseStored ? CommandType.StoredProcedure : CommandType.Text,
CommandText = Query
};
}
catch(MySqlException ex)
{
Error.SendToDeveloper("DbHelper.Open()", ex.ToString());
throw;
}
}
/// <summary>
/// use in select statements
/// </summary>
public DataTable GetData(MySqlParameter[] parameters)
{
var result = new DataTable();
try
{
if (parameters != null)
{
foreach (var param in parameters)
{
_command.Parameters.Add(param);
}
}
using (var dataAdapter = new MySqlDataAdapter(_command))
{
dataAdapter.Fill(result);
}
}
catch(MySqlException ex)
{
Error.SendToDeveloper("DbHelper.GetData()", ex.ToString());
throw;
}
return result;
}
/// <summary>
/// use in create, update and insert statements
/// </summary>
public int ExecuteNonQuery(MySqlParameter[] parameters)
{
int result = 0;
try
{
if (parameters != null)
{
foreach (var param in parameters)
{
_command.Parameters.Add(param);
}
}
result = _command.ExecuteNonQuery();
}
catch(MySqlException ex)
{
Error.SendToDeveloper("DbHelper.ExecuteNonQuery", ex.ToString());
throw;
}
return result;
}
/// <summary>
/// use in commiting transactions
/// </summary>
public void Commit()
{
try
{
_transaction.Commit();
}
catch (MySqlException ex)
{
Error.SendToDeveloper("DbHelper.Commit", ex.ToString());
throw;
}
}
/// <summary>
/// use in rolling back transactions
/// </summary>
public void RollBack()
{
try
{
_transaction.Rollback();
}
catch (MySqlException ex)
{
Error.SendToDeveloper("DbHelper.RollBack", ex.ToString());
throw;
}
}
}
以下是我通过电子邮件收到的例外情况：
MySql.Data.MySqlClient.MySqlException (0x80004005): Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding. ---> System.TimeoutException: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond ---> System.IO.IOException: Unable to read data from the transport connection: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond. ---> System.Net.Sockets.SocketException: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond
at System.Net.Sockets.Socket.Receive(Byte[] buffer, Int32 offset, Int32 size, SocketFlags socketFlags)
at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)
--- End of inner exception stack trace ---
at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)
at MySql.Data.Common.MyNetworkStream.Read(Byte[] buffer, Int32 offset, Int32 count)
--- End of inner exception stack trace ---
at MySql.Data.Common.MyNetworkStream.HandleOrRethrowException(Exception e)
at MySql.Data.Common.MyNetworkStream.Read(Byte[] buffer, Int32 offset, Int32 count)
at MySql.Data.MySqlClient.TimedStream.Read(Byte[] buffer, Int32 offset, Int32 count)
at System.IO.BufferedStream.Read(Byte[] array, Int32 offset, Int32 count)
at MySql.Data.MySqlClient.MySqlStream.ReadFully(Stream stream, Byte[] buffer, Int32 offset, Int32 count)
at MySql.Data.MySqlClient.MySqlStream.LoadPacket()
at MySql.Data.MySqlClient.MySqlStream.ReadPacket()
at MySql.Data.MySqlClient.NativeDriver.GetResult(Int32& affectedRow, Int64& insertedId)
at MySql.Data.MySqlClient.Driver.GetResult(Int32 statementId, Int32& affectedRows, Int64& insertedId)
at MySql.Data.MySqlClient.Driver.NextResult(Int32 statementId, Boolean force)
at MySql.Data.MySqlClient.MySqlDataReader.NextResult()
at MySql.Data.MySqlClient.MySqlCommand.ExecuteReader(CommandBehavior behavior)
at MySql.Data.MySqlClient.ExceptionInterceptor.Throw(Exception exception)
at MySql.Data.MySqlClient.MySqlConnection.Throw(Exception ex)
at MySql.Data.MySqlClient.MySqlConnection.HandleTimeoutOrThreadAbort(Exception ex)
at MySql.Data.MySqlClient.MySqlCommand.ExecuteReader(CommandBehavior behavior)
at MySql.Data.MySqlClient.MySqlCommand.ExecuteReader()
at MySql.Data.MySqlClient.Driver.LoadServerProperties(MySqlConnection connection)
at MySql.Data.MySqlClient.Driver.Configure(MySqlConnection connection)
at MySql.Data.MySqlClient.MySqlConnection.Open()
at TechSol.DbHelper.Open()
以下是该类的示例用法，如果出现问题，将显示错误消息：
try
{
using (var db = new DbHelper())
{
db.ConnectionString = _connString;
db.Query = "InsertTransaction";
db.UseStored = true;
db.Open();
db.ExecuteNonQuery();
}
}
catch(MySqlException mySex)
{
string message = string.Format("{0} \r\n\r\n Please try again! \r\n\r\n Please contact developer", mySex.Message);
MessageBox.Show(message, "Error");
}
我希望我能为此明确提出问题。非常感谢！
- 编辑 -
这是静态错误类：
public static class Error
{
public static void SendToDeveloper(string location, string body)
{
using (var message = new MailMessage())
{
message.To.Add(ConfigurationManager.AppSettings["dev_mail"]);
message.From = new MailAddress(ConfigurationManager.AppSettings["email_sender"]);
message.Subject = string.Format("Error in {0}, {1}, {2}",
ConfigurationManager.AppSettings["application_name"], location,
DateTime.Now);
message.Body = body;
try
{
var smtp = new SmtpClient(ConfigurationManager.AppSettings["smtp_server"]);
smtp.Send(message);
}
catch (SmtpException sex)
{
SendToDeveloper("Error.SMTPCLIENT", sex.ToString());
throw;
}
}
}
}
这是连接字符串：
<add name="conn_string" connectionString="Server=server;uid=user;Database=database;Pwd=pass;Convert Zero Datetime=True;"
xdt:Transform="Replace" xdt:Locator="Match(name)"/>