C# conditional using block statement

Question

I have the follow code but it is awkward. How could I better structure it? Do I have to make my consuming class implement IDisposable and conditionally construct the network acc

Answer 1

One option, which is somewhat nasty but would work, based on the fact that the C# compiler calls Dispose only if the resource is non-null:

protected void ValidateExportDirectoryExists()
{
    using (useNetworkAccess 
               ? new Core.NetworkAccess(username, password, domain)
               : null)
    {
        CheckExportDirectoryExists();
    }
}

Another alternative would be to write a static method which returned either null or a NetworkAccess:

private Core.NetworkAccess CreateNetworkAccessIfNecessary()
{
    return useNetworkAccess
        ? new Core.NetworkAccess(username, password, domain)) : null;
}

Then:

protected void ValidateExportDirectoryExists()
{
    using (CreateNetworkAccessIfNecessary())
    {
        CheckExportDirectoryExists();
    }
}

Again, I'm still not sure I don't prefer the original... it really depends on how often you need this pattern.

Answer 2

using scope will only dispose a object if the class implements IDisposible interface so yes you need to implement dispose method.

Answer 3

protected void ValidateExportDirectoryExists()
{
      var access = useNetworkAccess
          ? new Core.NetworkAccess(username, password, domain)
            : null;

      using (access)
      {
          CheckExportDirectoryExists();
      }
}

Answer 4

Whatever is enclosed within the using statement will have it's IDispoable.Dispose called as dictated by the IDisposable interface. As seen on MSDN for using...

Provides a convenient syntax that ensures the correct use of IDisposable objects.

Therefore if you put a custom type within the using statement it should clean up its resources appropriately via the IDisposable interface.