title: WPF re-size border at runtime
body: <p>Does setting a Framework elements (Border in this case) width in XAML prevent me from changing this value at run time? </p>
  
  <p>I have a grid containing a border which in turn contains some other controls. I have an animation which expands the grid and border width and height increasing the values from 0.</p>
  
  <p>I have then placed a button above the border to act as a re-sizing aid (it is a border-less window). here is a snippet of the code that should be re-sizing the border:</p>
  
  <pre><code>private void GridResize_Click(object sender, RoutedEventArgs e)
  {
  
          startPoint = this.PointToScreen(Mouse.GetPosition(this));
          Mouse.Capture(GridResize);
          Resizing = true;
  
  }
  
  private void Window_MouseMove(object sender, MouseEventArgs e)
  {
          if (Resizing)
          {
              FrameworkElement border = (FrameworkElement)LibraryBorder;
              //an arbitrary value for testing 
              border.Width += 20;
              LibraryBorder.InvalidateVisual();
          }
  }
  </code></pre>
  
  <p>The initial animation sets the borders width to 1500. When debugging both events are being registered and Window_MouseMove is trying to amend the borders width. It does not however alter the value - it remains at 1500. I cast the element to a FrameworkElement in the hope that this would allow me to amend the width property. I assume that my xaml values are somehow overriding my code. Any ideas on how to get around this. I thought I would ask before I go the route of moving all my animations in to code to discover there is a better way ( or that the code approach wont make a difference!!).</p>
  
  <p>Thanks in advance for any answers</p>