When to dispose and why?

Question

I asked a question about this method:

// Save an object out to the disk
public static void SerializeObject(this T toSerialize, String filename)
{
           


        

Answer 1

Well actually you already are disposing it since the textWriter.Close Method does it.

public virtual void Close()
{
    this.Dispose(true);
    GC.SuppressFinalize(this);
}

So you could change your code to. This

public static void SerializeObject(this T toSerialize, String filename)
{
    TextWriter textWriter;
    try
    {
         XmlSerializer xmlSerializer = new XmlSerializer(toSerialize.GetType());
         textWriter = new StreamWriter(filename);

          xmlSerializer.Serialize(textWriter, toSerialize);
    }
    finally
   {
       textWriter.Close();
   }

Which is pretty similar to what the using() does in the other answers.

The impact of not doing this is that if an error occurs with Serialize it would be a while before the Framework gave up its file lock (when it Processes the fReachable queue).

I know FxCop tells you when to implment IDisposable but I don't think there's any easy way to find out when you need to call Dispose other than looking at the Docs and seeing if an object implments IDisposable (or intellisense).