DockPanel

The DockPanel control lays out multiple controls horizontally or vertically, with each control snapping to the top, bottom, left or right side of the DockPanel according to its DockPanel.Dock attached property. The final child control occupies the remaining area after the other controls have been laid out. (This can be suppressed by setting DockPanel.LastChildFill to false.)

CopyDocking controls with a DockPanel
<ms:DockPanel>
  <local:Dashboard ms:DockPanel.Dock="Top" />
  <local:ToolBox ms:DockPanel.Dock="Left" />
  <local:MainView />  <!-- fills remaining area -->
</ms:DockPanel>