我正在尝试从数据库中提取一些二进制数据并将它们写入 pdf 文件。在大多数情况下，这进展顺利，但偶尔的数据行似乎会抛出一个特定的错误 -
超时已过。在操作完成之前超时时间已过或服务器没有响应。
请记住，这只发生在少数几行上，而且绝不是随机的。相同的行总是抛出异常。我不确定为什么会抛出异常，但我可以跳过确实导致问题的行并继续前进。然而，我的问题是，当我捕捉到异常然后尝试移动到下一行时，我遇到了另一个异常 -
InvalidOperationException - 阅读器关闭时调用 Read 的尝试无效。
这是否意味着阅读器一旦遇到异常就会自动关闭？如果没有任何戏剧，我将如何进入下一行？
while (sdrReader.Read()) // Second exception happens here
{
try
{
byte[] byteData = new Byte[(sdrReader.GetBytes(0, 0, null, 0, int.MaxValue))]; // first exception happens here
sdrReader.GetBytes(0, 0, byteData, 0, byteData.Length);
string strOutputFileName = sdrReader.GetInt32(1).ToString() + ".pdf";
msMemoryStreams = new MemoryStream();
msMemoryStreams.Write(byteData, 0, byteData.Length);
byte[] byteArray = msMemoryStreams.ToArray();
msMemoryStreams.Flush();
msMemoryStreams.Close();
writeByteArrayToFile(byteData, txtFilesPath.Text + "\\" + strOutputFileName);
}
catch (Exception e)
{
Logger.Write("Document failed to convert: " + e.Message);
}
}
堆栈跟踪，根据要求 -
at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection)
at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj)
at System.Data.SqlClient.TdsParserStateObject.ReadSniError(TdsParserStateObject stateObj, UInt32 error)
at System.Data.SqlClient.TdsParserStateObject.ReadSni(DbAsyncResult asyncResult, TdsParserStateObject stateObj)
at System.Data.SqlClient.TdsParserStateObject.ReadNetworkPacket()
at System.Data.SqlClient.TdsParserStateObject.ReadBuffer()
at System.Data.SqlClient.TdsParserStateObject.ReadByteArray(Byte[] buff, Int32 offset, Int32 len)
at System.Data.SqlClient.TdsParser.ReadSqlValue(SqlBuffer value, SqlMetaDataPriv md, Int32 length, TdsParserStateObject stateObj)
at System.Data.SqlClient.SqlDataReader.ReadColumnData()
at System.Data.SqlClient.SqlDataReader.ReadColumn(Int32 i, Boolean setTimeout)
at System.Data.SqlClient.SqlDataReader.GetSqlBinary(Int32 i)
at System.Data.SqlClient.SqlDataReader.GetBytesInternal(Int32 i, Int64 dataIndex, Byte[] buffer, Int32 bufferIndex, Int32 length)
at System.Data.SqlClient.SqlDataReader.GetBytes(Int32 i, Int64 dataIndex, Byte[] buffer, Int32 bufferIndex, Int32 length)
at Pdf2Rtf.Form1.Read() in F:\Code\Pdf2Rtf\Pdf2Rtf\Pdf2Rtf\Form1.cs:line 77
at Pdf2Rtf.Form1.btnRead_Click(Object sender, EventArgs e) in F:\Code\Pdf2Rtf\Pdf2Rtf\Pdf2Rtf\Form1.cs:line 24
at System.Windows.Forms.Control.OnClick(EventArgs e)
at System.Windows.Forms.Button.OnClick(EventArgs e)
at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.ButtonBase.WndProc(Message& m)
at System.Windows.Forms.Button.WndProc(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData)
at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
at System.Windows.Forms.Application.Run(Form mainForm)
at Pdf2Rtf.Program.Main() in F:\Code\Pdf2Rtf\Pdf2Rtf\Pdf2Rtf\Program.cs:line 18
at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args)
at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ThreadHelper.ThreadStart()