title: viewmodel and view control order of execution
body: <p>I have a serious problem with the order of execution in MVVM:
  this code instaceiate the view (XAML):</p>
  
  <pre><code>&lt;local:ExecutionView x:Name="ExecutionView" DataContext="{Binding ExecutionViewNodel}"/&gt;
  </code></pre>
  
  <p><code>ExecutionView</code>  has inner field of viewmodel (<code>_viewModel = DataContext as ExecutionViewModel;</code>).
  In its CTOR it uses the viewmodel- <code>_viewModel.DoSomthing();</code></p>
  
  <p>problem is that it is null..</p>
  
  <p>I cant control the timing of the binding- i have read a bit and there ways of handling the issue with (Loaded event and datacontextchanged)- still i think it is a workaround and NOT the way it should be done.</p>
  
  <p>i need a way to control the steps where i can write a function that will be called once after the DataContext is certain to be valid.</p>
  
  <p>BR, Mosh.</p>