MemoryStream, XmlTextWriter and Warning 4 CA2202 : Microsoft.Usage
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Published on 2010-12-21T20:51:58Z
Indexed on
2010/12/21
20:54 UTC
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The Run Code Analysis command in Visual Studio 2010 Ultimate returns a warning when seeing a certain pattern with MemoryStream
and XmlTextWriter
.
This is the warning:
Warning 7 CA2202 : Microsoft.Usage : Object 'ms' can be disposed more than once in method 'KinteWritePages.GetXPathDocument(DbConnection)'. To avoid generating a System.ObjectDisposedException you should not call Dispose more than one time on an object.: Lines: 421 C:\Visual Studio 2010\Projects\Songhay.DataAccess.KinteWritePages\KinteWritePages.cs 421 Songhay.DataAccess.KinteWritePages
This is the form:
static XPathDocument GetXPathDocument(DbConnection connection)
{
XPathDocument xpDoc = null;
var ms = new MemoryStream();
try
{
using(XmlTextWriter writer = new XmlTextWriter(ms, Encoding.UTF8))
{
using(DbDataReader reader = CommonReader.GetReader(connection, Resources.KinteRssSql))
{
writer.WriteStartDocument();
writer.WriteStartElement("data");
do
{
while(reader.Read())
{
writer.WriteStartElement("item");
for(int i = 0; i < reader.FieldCount; i++)
{
writer.WriteRaw(String.Format("<{0}>{1}</{0}>", reader.GetName(i), reader[i].ToString()));
}
writer.WriteFullEndElement();
}
} while(reader.NextResult());
writer.WriteFullEndElement();
writer.WriteEndDocument();
writer.Flush();
ms.Position = 0;
xpDoc = new XPathDocument(ms);
}
}
}
finally
{
ms.Dispose();
}
return xpDoc;
}
The same kind of warning is produced for this form:
XPathDocument xpDoc = null;
using(var ms = new MemoryStream())
{
using(XmlTextWriter writer = new XmlTextWriter(ms, Encoding.UTF8))
{
using(DbDataReader reader = CommonReader.GetReader(connection, Resources.KinteRssSql))
{
//...
}
}
}
return xpDoc;
By the way, the following form produces another warning:
XPathDocument xpDoc = null;
var ms = new MemoryStream();
using(XmlTextWriter writer = new XmlTextWriter(ms, Encoding.UTF8))
{
using(DbDataReader reader = CommonReader.GetReader(connection, Resources.KinteRssSql))
{
//...
}
}
return xpDoc;
The above produces the warning:
Warning 7 CA2000 : Microsoft.Reliability : In method 'KinteWritePages.GetXPathDocument(DbConnection)', object 'ms' is not disposed along all exception paths. Call System.IDisposable.Dispose on object 'ms' before all references to it are out of scope. C:\Visual Studio 2010\Projects\Songhay.DataAccess.KinteWritePages\KinteWritePages.cs 383 Songhay.DataAccess.KinteWritePages
In addition to the following, what are my options?:
- Supress warning CA2202.
- Supress warning CA2000 and hope that
Microsoft is disposing of
MemoryStream
(because Reflector is not showing me the source code). - Rewrite my legacy code to recognize
the wonderful
XDocument
and LINQ to XML.
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