.NET：SqlDataReader.Close或.Dispose结果超时到期异常 [英] .NET: SqlDataReader.Close or .Dispose results in Timeout Expired exception

问题描述

当试图调用关闭或处置一个SqlDataReader我得到一个超时到期的异常。如果你有一个DbConnection到SQL Server，你可以自己再现它：

When trying to call Close or Dispose on an SqlDataReader i get a timeout expired exception. If you have a DbConnection to SQL Server, you can reproduce it yourself with:

String CRLF = "\r\n";
String sql = 
    "SELECT * " + CRLF +
    "FROM (" + CRLF +
    "   SELECT (a.Number * 256) + b.Number AS Number" + CRLF +
    "   FROM    master..spt_values a," + CRLF +
    "       master..spt_values b" + CRLF +
    "   WHERE   a.Type = 'p'" + CRLF +
    "       AND b.Type = 'p') Numbers1" + CRLF +
    "   FULL OUTER JOIN (" + CRLF +
    "       SELECT (print("code sample");a.Number * 256) + b.Number AS Number" + CRLF +
    "       FROM    master..spt_values a," + CRLF +
    "           master..spt_values b" + CRLF +
    "       WHERE   a.Type = 'p'" + CRLF +
    "           AND b.Type = 'p') Numbers2" + CRLF +
    "   ON 1=1";

DbCommand cmd = connection.CreateCommand();
cmd.CommandText = sql;
DbDataReader rdr = cmd.ExecuteReader();
rdr.Close();

如果调用reader.Close（）或reader.Dispose（），它将抛出一个System.Data .SqlClient.SqlException：

If you call reader.Close() or reader.Dispose() it will throw a System.Data.SqlClient.SqlException:

• ErrorCode：-2146232060（0x80131904）


• 讯息：

推荐答案

这是因为你刚刚打开了数据读取器，还没有完全迭代。您将需要.Cancel（）您的DbCommand对象，然后再尝试关闭尚未完成的数据读取器（以及DbConnection）。当然，通过.Cancel（） - 你的DbCommand，我不知道这个，但你可能会遇到一些其他异常。但你应该赶上它，如果发生。

it's because you have just opened the data reader and have not completely iterated through it yet. you will need to .Cancel() your DbCommand object before you attempt to close a data reader that hasn't completed yet (and the DbConnection as well). of course, by .Cancel()-ing your DbCommand, I'm not sure of this but you might encounter some other exception. but you should just catch it if it happens.

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