Dispose of object more than one time error. CA2202. Is there a better way?

How can I ensure the following code is disposing of all objects in a better fashion? Currently, Code Analysis is telling me

Error 45 CA2202 : Microsoft.Usage : Object 'ns' can be disposed more than once in method 'CPCommunicator.GetResults(string)'. To avoid generating a System.ObjectDisposedException you should not call Dispose more than one time on an object.: Lines: 64开发者_StackOverflow中文版, 65

NetworkStream ns = null;
StreamWriter requestStream = null;
TextReader responseStream = null;

var results = new StringBuilder();

try
{
    ns = new NetworkStream(CreateConnection(), true);
    requestStream = new StreamWriter(ns);
    requestStream.Flush();
    responseStream = new StreamReader(ns);

    requestStream.Write(reportData);
    requestStream.Flush();
    while (responseStream.Peek() != -1)
    {
        var currentLine = responseStream.ReadLine();
        results.Append(currentLine);
        results.Append("\n");
    }
}
finally
{
    if (requestStream != null) requestStream.Close();
    if (responseStream != null) responseStream.Close();
    if (cpNetworkStream != null) cpNetworkStream.Close();
}

Since both requestStream and responseStream use ns, they both dispose of ns so in order to satisfy the code analysis warning, I have to comment out the last two close methods in the finally block. But do I really want to do this?????

Yes, imho you really should only call it once.

Alternatively you could use the using syntax on ns, which makes the whole situation even clearer.

using (ns = new NetworkStream(CreateConnection(), true)) {
   ...
}

I would refactor your code to be like this:

using (NetworkStream ns = new NetworkStream(CreateConnection(), true))
using (StreamWriter requestStream = new StreamWriter(ns))
using (TextReader responseStream = new StreamReader(ns))
{

    var results = new StringBuilder();

    requestStream.Flush();

    requestStream.Write(reportData);
    requestStream.Flush();
    while (responseStream.Peek() != -1)
    {
        var currentLine = responseStream.ReadLine();
        results.Append(currentLine);
        results.Append("\n");
    }
}