Get Response.output size?
<p>My code is now like this:</p>

<pre><code>var xmlSerializer = new XmlSerializer(typeof(DataSet));
xmlSerializer.Serialize(Response.Output, ds);
</code></pre>

<p>After that I want to show the size, but this gives me an error:</p>

<pre><code>Response.AddHeader("Content-Length", Response.OutputStream.Length.ToString());
</code></pre>

<p>The error is</p>

<pre><code>NotSupportedException was unhandled by user code
</code></pre>
