/// <summary>
/// This will search for a child of the specified type. The search is performed
/// hierarchically, breadth first (as opposed to depth first).
/// </summary>
/// <typeparam name="T">The type of the element to find</typeparam>
/// <param name="parent">The root of the tree to search for. This element itself is not checked.</param>
/// <param name="additionalCheck">Provide a callback to check additional properties
/// of the found elements. Can be left Null if no additional criteria are needed.</param>
/// <returns>Returns the found element. Null if nothing is found.</returns>
/// <example>Button button = TreeHelper.FindChild<Button>( this, foundChild => foundChild.Focusable );</example>
public static T FindChild <T>(DependencyObject parent, Func <T, bool> additionalCheck) where T : DependencyObject
{
int childrenCount = VisualTreeHelper.GetChildrenCount(parent);
T child;
for (int index = 0; index < childrenCount; index++)
{
child = VisualTreeHelper.GetChild(parent, index) as T;
if (child != null)
{
if (additionalCheck == null)
{
return(child);
}
else
{
if (additionalCheck(child))
{
return(child);
}
}
}
}
for (int index = 0; index < childrenCount; index++)
{
child = TreeHelper.FindChild <T>(VisualTreeHelper.GetChild(parent, index), additionalCheck);
if (child != null)
{
return(child);
}
}
return(null);
}
/// <summary>
/// This will search for a child of the specified type. The search is performed
/// hierarchically, breadth first (as opposed to depth first).
/// </summary>
/// <typeparam name="T">The type of the element to find</typeparam>
/// <param name="parent">The root of the tree to search for. This element itself is not checked.</param>
/// <returns>Returns the found element. Null if nothing is found.</returns>
public static T FindChild <T>(DependencyObject parent) where T : DependencyObject
{
return(TreeHelper.FindChild <T>(parent, null));
}