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Continuing with the theme of standing on the shoulders of those who came before us…

Today, I need to find a control “somewhere” in the visual tree.  I found two different solutions to the issue.  One finds child controls.  The other finds ancestors.  Since I copped the code from other sites (link in the comments section for each method) I won’t promise that everything works to perfection.  I’ve used the FindVisualChildByName<T>() method in my code so my confidence is higher with that one.

Here’s the class I ended up with: 

public static class VisualTreeHelpers
  {

    /// <summary>
    /// Find a named control in the visual tree where you have the parent control and need to find the child control.
    /// Found at: http://pwnedcode.wordpress.com/2009/04/01/find-a-control-in-a-wpfsilverlight-visual-tree-by-name/
    /// </summary>
    /// <typeparam name="T">Control type you're looking for.</typeparam>
    /// <param name="parent">Known parent control.</param>
    /// <param name="name">Name of control you're looking for.</param>
    /// <returns>The target control or null.</returns>
    /// <example>var xamDockManager = VisualTreeHelpers.FindVisualChildByName<XamDockManager>(Application.Current.MainWindow, "XamDockManager1");</example>
    public static T FindVisualChildByName<T>(DependencyObject parent, string name) where T : DependencyObject
    {

      for (var i = 0; i < VisualTreeHelper.GetChildrenCount(parent); i++)
      {
        var child = VisualTreeHelper.GetChild(parent, i);
        var controlName = child.GetValue(Control.NameProperty) as string;
        if (controlName == name)
          return child as T;

        var result = FindVisualChildByName<T>(child, name);
        if (result != null)
          return result;
      }
      return null;
    }

    /// <summary>
    /// Find a named control in the visual tree where you have the child control and need to find the ancestor control.
    /// Found at: http://www.wpftutorial.net/LogicalAndVisualTree.html
    /// </summary>
    /// <typeparam name="T">Control type you're looking for.</typeparam>
    /// <param name="dependencyObject">The child control.</param>
    /// <returns>The target control or null.</returns>
    public static T FindAncestor<T>(DependencyObject dependencyObject) where T : class
    {
      var target = dependencyObject;
      do
      {
        target = VisualTreeHelper.GetParent(target);
      }
      while (target != null && !(target is T));
      return target as T;
    }

  }

Notes:

My class name is a plural as to not conflict with the VisualTreeHelper from Microsoft.

I’m not happy with the magic-string for find the control name that gets passed in during the call, but that problem is outside the scope of this topic. 

There’s always more to learn…