Action in C# 3.0

I am coding a C# .NET 3.0 asynchronous call to a WCF service. And I get the following error.

Error 1 开发者_如何学运维Using the generic type 'System.Action' requires '1' type arguments.

But when doing this in .NET 3.5 no error occurs. Doesn't .NET 3.0 support this or I am doing wrong. I have to use .NET 3.0 because iam writing a application for XPe.

This is how my code looks like.

AsyncCallback aSyncCallBack =
delegate(IAsyncResult result)
{
    try
    {
        service.EndSubscribe(result);

        this.Dispatcher.BeginInvoke((Action)delegate
        { DGStudent.ItemsSource = test; });
    }
    catch (Exception ex)
    {
        this.Dispatcher.BeginInvoke((Action)delegate
        { MessageBox.Show(ex.Message); });
    }
};

The non-generic System.Action was introduced in .NET 3.5 and cannot be used from .NET 3.0. The compiler thinks you mean the generic System.Action<T> which does require a type parameter.

All the Action delegates apart from Action<T> were only added in .NET 3.5; they're not available in 3.0. If you have a look at the documentation, the Action documentation only has versions for 3.5 and 4.0, whereas the Action<T> documentation goes back to 2.0.

You'll have to create your own version of a no-args delegate, or use something similar like MethodInvoker in winforms.