Accessing XAML object in codebehind(WPF)

I'm creating object in XAML like this

<Window.Resources>
        <local:DataReceiver x:Key="request">
        </l开发者_如何学Cocal:DataReceiver>
    </Window.Resources>

how can I call this objects method from codebehind?

---

var dataReceiver = (DataReceiver)FindResource("request");
...

---

DataReceiver request = this.TryFindResource("request") as DataReceiver;
if (request != null)
{
   // your code here
}