title: ColSpan for Silverlight Datagrid
body: <p>I have a need to customize a Datagrid, for a TimeManagement system, using rowspawns.
  My desired look is something like:</p>
  
  <pre><code>Customers| Projects  | Tasks  | Moanday | Tuesday | Wednesday | Thursday | Friday |
           |           | Task 1 |   0     |   0     |    0      |    0     |   0    |
  Customer1| Project 1 | Task 2 |   0     |   0     |    0      |    0     |   0    |
           |           | Task 3 |   0     |   0     |    0      |    0     |   0    |
  </code></pre>
  
  <p>Preferebly, i would like to be able to just give the DataGrid.ItemSource a List of Customers and it should work based on that.
  My current Model is</p>
  
  <pre><code>    public class Customer
      {
         public string Name{get; set;}
         public List&lt;Project&gt; Projects{ get; set;}
      }
      public class Project
      {
         public string Name {get; set;}
         public List&lt;Task&gt; Tasks{ get; set; }
      }
      public class Task
      {
         public string Name { get; set;}
         public Week Week { get; set; }
      }
      public class Week 
      {
         public double Monday { get; set; }
         ...
      } 
  </code></pre>
  
  <ul>
  <li>I would like the Customer Cell to have a rowspan over all of its project rows.</li>
  <li>I would like the Project cell to have a rowspan over all of its task rows. </li>
  <li>And, most importantly, i need the user to be able to navigate around using the      arrowkeys on the keyboard.</li>
  </ul>
  
  <p>My first attempt was to create new datagrids inside cells of another datagrid.
  It seems a user is not able to navigate from one datagrid to another using the arrowkeys.</p>
  
  <p>Any help is much appreciated.</p>