title: Lookin for some way to copy XAML MenuItem properties to a button in a single step
body: <p>Assume that i have multiple menu-items like this one:</p>
  
  <pre><code>&lt;MenuItem Name="MenuItemDownload" Command="{Binding DownloadCommand}"
            Header="Download"
            ToolTip="Some long description of whats happening..."&gt;
      &lt;MenuItem.Icon&gt;
          &lt;Image Source="/Resources/download.png"
                 Width="{Binding Source.PixelWidth, RelativeSource={RelativeSource self}}" /&gt;
      &lt;/MenuItem.Icon&gt;
  &lt;/MenuItem&gt;
  </code></pre>
  
  <p>For some of this menu-items i have toolbar-buttons, currently defined like this:</p>
  
  <pre><code>&lt;Button Command="{Binding DownloadCommand}"
          ToolTip="{Binding ElementName=MenuItemDownload, Path=ToolTip}"&gt;
      &lt;Image Source="{Binding ElementName=MenuItemDownload, Path=Icon.Source}"
             Width="{Binding Source.PixelWidth, RelativeSource={RelativeSource self}}" /&gt;
  &lt;/Button&gt;
  </code></pre>
  
  <p>This works. And I can define everything once and transfer it to the button. But I am lookin for something like "this is menu-item is your reference element. copy/bind everything thats defined and relevant to you"...   Something like</p>
  
  <pre><code>&lt;Button IsMirroring="{Binding ElementName=MenuItemDownload}" /&gt;
  </code></pre>
  
  <p>I am sure its possible... But how? Please give me some keywords or hints :)</p>