How can I find WPF controls by name or type?

Question

I need to search a WPF control hierarchy for controls that match a given name or type. How can I do this?

Answer 1

I combined the template format used by John Myczek and Tri Q's algorithm above to create a findChild Algorithm that can be used on any parent. Keep in mind that recursively searching a tree downwards could be a lengthy process. I've only spot-checked this on a WPF application, please comment on any errors you might find and I'll correct my code.

WPF Snoop is a useful tool in looking at the visual tree - I'd strongly recommend using it while testing or using this algorithm to check your work.

There is a small error in Tri Q's Algorithm. After the child is found, if childrenCount is > 1 and we iterate again we can overwrite the properly found child. Therefore I added a if (foundChild != null) break; into my code to deal with this condition.

/// <summary> /// Finds a Child of a given item in the visual tree.  /// </summary> /// <param name="parent">A direct parent of the queried item.</param> /// <typeparam name="T">The type of the queried item.</typeparam> /// <param name="childName">x:Name or Name of child. </param> /// <returns>The first parent item that matches the submitted type parameter.  /// If not matching item can be found,  /// a null parent is being returned.</returns> public static T FindChild<T>(DependencyObject parent, string childName)    where T : DependencyObject {       // Confirm parent and childName are valid.    if (parent == null) return null;    T foundChild = null;    int childrenCount = VisualTreeHelper.GetChildrenCount(parent);   for (int i = 0; i < childrenCount; i++)   {     var child = VisualTreeHelper.GetChild(parent, i);     // If the child is not of the request child type child     T childType = child as T;     if (childType == null)     {       // recursively drill down the tree       foundChild = FindChild<T>(child, childName);        // If the child is found, break so we do not overwrite the found child.        if (foundChild != null) break;     }     else if (!string.IsNullOrEmpty(childName))     {       var frameworkElement = child as FrameworkElement;       // If the child's name is set for search       if (frameworkElement != null && frameworkElement.Name == childName)       {         // if the child's name is of the request name         foundChild = (T)child;         break;       }     }     else     {       // child element found.       foundChild = (T)child;       break;     }   }    return foundChild; } 

Call it like this:

TextBox foundTextBox =     UIHelper.FindChild<TextBox>(Application.Current.MainWindow, "myTextBoxName"); 

Note Application.Current.MainWindow can be any parent window.