我想從NHibernate的SqlClientBatchingBatcher類繼承的正是這樣(從TooManyRowsAffectedException with encrypted triggers採取代碼):如何在override中訪問超類的私有成員?
public class NonBatchingBatcherWithoutVerification : SqlClientBatchingBatcher
{
public NonBatchingBatcherWithoutVerification(ConnectionManager connectionManager, IInterceptor interceptor) : base(connectionManager, interceptor)
{}
protected override void DoExecuteBatch(IDbCommand ps)
{
log.DebugFormat("Executing batch");
CheckReaders();
Prepare(currentBatch.BatchCommand);
if (Factory.Settings.SqlStatementLogger.IsDebugEnabled)
{
Factory.Settings.SqlStatementLogger.LogBatchCommand(currentBatchCommandsLog.ToString());
currentBatchCommandsLog = new StringBuilder().AppendLine("Batch commands:");
}
int rowsAffected = currentBatch.ExecuteNonQuery();
// Removed the following line
//Expectations.VerifyOutcomeBatched(totalExpectedRowsAffected, rowsAffected);
currentBatch.Dispose();
totalExpectedRowsAffected = 0;
currentBatch = new SqlClientSqlCommandSet();
}
}
只是發現一些在法訪問這裏(如currentBatch中或totalExpectedRowsAffected)成員。
那麼,事實證明,這些成員實際上是私有的在當前的NHibernate 3.3源的超類。那麼如何在不復制整個事物的情況下有效地繼承這個類?這是該類未修改的NHibernate代碼:
public class SqlClientBatchingBatcher : AbstractBatcher
{
private int _batchSize;
private int _totalExpectedRowsAffected;
private SqlClientSqlCommandSet _currentBatch;
private StringBuilder _currentBatchCommandsLog;
private readonly int _defaultTimeout;
public SqlClientBatchingBatcher(ConnectionManager connectionManager, IInterceptor interceptor)
: base(connectionManager, interceptor)
{
_batchSize = Factory.Settings.AdoBatchSize;
_defaultTimeout = PropertiesHelper.GetInt32(Cfg.Environment.CommandTimeout, Cfg.Environment.Properties, -1);
_currentBatch = CreateConfiguredBatch();
//we always create this, because we need to deal with a scenario in which
//the user change the logging configuration at runtime. Trying to put this
//behind an if(log.IsDebugEnabled) will cause a null reference exception
//at that point.
_currentBatchCommandsLog = new StringBuilder().AppendLine("Batch commands:");
}
public override int BatchSize
{
get { return _batchSize; }
set { _batchSize = value; }
}
protected override int CountOfStatementsInCurrentBatch
{
get { return _currentBatch.CountOfCommands; }
}
public override void AddToBatch(IExpectation expectation)
{
_totalExpectedRowsAffected += expectation.ExpectedRowCount;
IDbCommand batchUpdate = CurrentCommand;
Driver.AdjustCommand(batchUpdate);
string lineWithParameters = null;
var sqlStatementLogger = Factory.Settings.SqlStatementLogger;
if (sqlStatementLogger.IsDebugEnabled || Log.IsDebugEnabled)
{
lineWithParameters = sqlStatementLogger.GetCommandLineWithParameters(batchUpdate);
var formatStyle = sqlStatementLogger.DetermineActualStyle(FormatStyle.Basic);
lineWithParameters = formatStyle.Formatter.Format(lineWithParameters);
_currentBatchCommandsLog.Append("command ")
.Append(_currentBatch.CountOfCommands)
.Append(":")
.AppendLine(lineWithParameters);
}
if (Log.IsDebugEnabled)
{
Log.Debug("Adding to batch:" + lineWithParameters);
}
_currentBatch.Append((System.Data.SqlClient.SqlCommand) batchUpdate);
if (_currentBatch.CountOfCommands >= _batchSize)
{
ExecuteBatchWithTiming(batchUpdate);
}
}
protected override void DoExecuteBatch(IDbCommand ps)
{
Log.DebugFormat("Executing batch");
CheckReaders();
Prepare(_currentBatch.BatchCommand);
if (Factory.Settings.SqlStatementLogger.IsDebugEnabled)
{
Factory.Settings.SqlStatementLogger.LogBatchCommand(_currentBatchCommandsLog.ToString());
_currentBatchCommandsLog = new StringBuilder().AppendLine("Batch commands:");
}
int rowsAffected;
try
{
rowsAffected = _currentBatch.ExecuteNonQuery();
}
catch (DbException e)
{
throw ADOExceptionHelper.Convert(Factory.SQLExceptionConverter, e, "could not execute batch command.");
}
Expectations.VerifyOutcomeBatched(_totalExpectedRowsAffected, rowsAffected);
_currentBatch.Dispose();
_totalExpectedRowsAffected = 0;
_currentBatch = CreateConfiguredBatch();
}
private SqlClientSqlCommandSet CreateConfiguredBatch()
{
var result = new SqlClientSqlCommandSet();
if (_defaultTimeout > 0)
{
try
{
result.CommandTimeout = _defaultTimeout;
}
catch (Exception e)
{
if (Log.IsWarnEnabled)
{
Log.Warn(e.ToString());
}
}
}
return result;
}
}
我忽略了什麼嗎?似乎是一個相當糟糕的方法來複制整個事情,只是爲了覆蓋所有私人成員的訪問權限。我只想重寫一種方法!
爲什麼你不要使用使用私人支持變量的屬性? – Blorgbeard 2013-03-20 20:51:26
我表達了自己的一點不清楚,現在會改變... – 2013-03-20 20:52:16