How can I find WPF controls by name or type?
Asked Answered
I

22

300

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

Idun answered 11/3, 2009 at 21:8 Comment(0)
C
342

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.

Cohberg answered 18/11, 2009 at 23:42 Comment(10)
@CrimsonX: Maybe I'm doing this wrong... I had a similar need where I needed to get to a control (ListBox) inside a ContentControl (Expander). The above code didn't work for me as is.. I had to update the above code to see if a leaf node (GetChildrenCount => 0) is a ContentControl. If yes, check if the content matches the name+type criteria.Sorayasorb
@Sorayasorb - I think it should work for this purpose. Can you copy & paste your code to show how you're using the call? I would expect it should be FindChild<ListBox>(Expander myExpanderName, "myListBoxName").Cohberg
@CrimsonX: FindChild<ListBox>( topLevelUserControl, "myListBoxName") & topLevelUserControl > DockPanel > StackPanel > Expander > ListBox The recursion would stop at the Expander ; since GetChildrenCount() would return 0.Sorayasorb
@Sorayasorb - It sounds like you're using the code as it was intended but have found a case where it doesn't completely work properly. I'm not completely familiar with why this wouldn't work properly. Feel free to post complete code in answering the question below or something like thatCohberg
@Cohberg - Done. Seems that logical children need to be factored into the equation. For details.. See my post in this question..Sorayasorb
Hi CrimsonX, By apply your solution, i can find my first TextBox which is generate automatically by ListBox. But how can i find specific item in my ListBox ex:the 2nd, 3rd ... item?Heng
@Cohberg I think I found another corner case. I was trying to find the PART_SubmenuPlaceholder in the RibbonApplicationMenuItem, but the code above was not working. To resolve it, I needed to add the following: if (name == ElementName) else { foundChild = FindChild(child, name) if (foundChild != null) break; }Flowerdeluce
Please be carefull, there is a bug or more in the answer. It will stop as soon as it will reach a child of the searched type. I think you should consider/prioritize other answers.Rheo
Snoop is your best shot it is pretty much similar to firebug for asp.net/htmlPlump
This code is great, but it won't work if you are not looking for a specific type of element, for example if you pass FrameworkElement as T, it's gonna return null as soon as first loop ends. so you gonna need do some modifications.Erotica
F
164

You can also find an element by name using FrameworkElement.FindName(string).

Given:

<UserControl ...>
    <TextBlock x:Name="myTextBlock" />
</UserControl>

In the code-behind file, you could write:

var myTextBlock = (TextBlock)this.FindName("myTextBlock");

Of course, because it's defined using x:Name, you could just reference the generated field, but perhaps you want to look it up dynamically rather than statically.

This approach is also available for templates, in which the named item appears multiple times (once per usage of the template).

Flying answered 25/9, 2009 at 12:48 Comment(3)
For this to work you don't necessarily have to add the "x:" to the name attribute.Janeyjangle
This doesnt seem to always work. I have UserControls which are combined together programmatically in nested grids as the contents of a properties window. CrimsonX's answer works fine however.Cichlid
This won't work for elements within ItemControls, ListBoxes, etc.Balakirev
E
73

You can use the VisualTreeHelper to find controls. Below is a method that uses the VisualTreeHelper to find a parent control of a specified type. You can use the VisualTreeHelper to find controls in other ways as well.

public static class UIHelper
{
   /// <summary>
   /// Finds a parent of a given item on the visual tree.
   /// </summary>
   /// <typeparam name="T">The type of the queried item.</typeparam>
   /// <param name="child">A direct or indirect child of the queried item.</param>
   /// <returns>The first parent item that matches the submitted type parameter. 
   /// If not matching item can be found, a null reference is being returned.</returns>
   public static T FindVisualParent<T>(DependencyObject child)
     where T : DependencyObject
   {
      // get parent item
      DependencyObject parentObject = VisualTreeHelper.GetParent(child);

      // we’ve reached the end of the tree
      if (parentObject == null) return null;

      // check if the parent matches the type we’re looking for
      T parent = parentObject as T;
      if (parent != null)
      {
         return parent;
      }
      else
      {
         // use recursion to proceed with next level
         return FindVisualParent<T>(parentObject);
      }
   }
}

Call it like this:

Window owner = UIHelper.FindVisualParent<Window>(myControl);
Enciso answered 11/3, 2009 at 21:28 Comment(1)
How do you get or what is myControl?Raguelragweed
P
25

I may be just repeating everyone else but I do have a pretty piece of code that extends the DependencyObject class with a method FindChild() that will get you the child by type and name. Just include and use.

public static class UIChildFinder
{
    public static DependencyObject FindChild(this DependencyObject reference, string childName, Type childType)
    {
        DependencyObject foundChild = null;
        if (reference != null)
        {
            int childrenCount = VisualTreeHelper.GetChildrenCount(reference);
            for (int i = 0; i < childrenCount; i++)
            {
                var child = VisualTreeHelper.GetChild(reference, i);
                // If the child is not of the request child type child
                if (child.GetType() != childType)
                {
                    // recursively drill down the tree
                    foundChild = FindChild(child, childName, childType);
                    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 = child;
                        break;
                    }
                }
                else
                {
                    // child element found.
                    foundChild = child;
                    break;
                }
            }
        }
        return foundChild;
    }
}

Hope you find it useful.

Paperhanger answered 1/10, 2009 at 0:52 Comment(1)
Per my post above, there is a small implementation error in your code: https://mcmap.net/q/99737/-how-can-i-find-wpf-controls-by-name-or-type/…Cohberg
C
21

If you want to find ALL controls of a specific type, you might be interested in this snippet too

    public static IEnumerable<T> FindVisualChildren<T>(DependencyObject parent) 
        where T : DependencyObject
    {
        int childrenCount = VisualTreeHelper.GetChildrenCount(parent);
        for (int i = 0; i < childrenCount; i++)
        {
            var child = VisualTreeHelper.GetChild(parent, i);

            var childType = child as T;
            if (childType != null)
            {
                yield return (T)child;
            }

            foreach (var other in FindVisualChildren<T>(child))
            {
                yield return other;
            }
        }
    }
Cost answered 10/2, 2012 at 14:23 Comment(3)
Good one but ensure control is loaded otherwise GetChildrenCount will return 0.Heman
@UrbanEsc, why do you cast child a second time? If you have childType of type T, you can write inside the if: yield return childType... no?Radiograph
@MassimilianoKraus Hey, sorry for the late response, but you are right. I attribute it to me rewriting this snippet several times, and thus this might be a fragment of a different checkCost
S
19

My extensions to the code.

  • Added overloads to find one child by type, by type and criteria (predicate), find all children of type which meet the criteria
  • the FindChildren method is an iterator in addition to being an extension method for DependencyObject
  • FindChildren walks logical sub-trees also. See Josh Smith's post linked in the blog post.

Source: https://code.google.com/p/gishu-util/source/browse/#git%2FWPF%2FUtilities

Explanatory blog post : http://madcoderspeak.blogspot.com/2010/04/wpf-find-child-control-of-specific-type.html

Sorayasorb answered 20/4, 2010 at 8:10 Comment(3)
-1 Exactly what I was about to implement (predicate, iterator, and extension method), but there's a 404 on the source link. Will change to +1 if code is included here, or source link is fixed!Shibboleth
@Shibboleth - Git migration killed the link it seems :) Here you go.. code.google.com/p/gishu-util/source/browse/…Sorayasorb
I guess this is the code, because the original link is empty. github.com/dmjensen/gishu-utilToothache
P
17

This will dismiss some elements - you should extend it like this in order to support a wider array of controls. For a brief discussion, have a look here

 /// <summary>
 /// Helper methods for UI-related tasks.
 /// </summary>
 public static class UIHelper
 {
   /// <summary>
   /// Finds a parent of a given item on the visual tree.
   /// </summary>
   /// <typeparam name="T">The type of the queried item.</typeparam>
   /// <param name="child">A direct or indirect child of the
   /// queried item.</param>
   /// <returns>The first parent item that matches the submitted
   /// type parameter. If not matching item can be found, a null
   /// reference is being returned.</returns>
   public static T TryFindParent<T>(DependencyObject child)
     where T : DependencyObject
   {
     //get parent item
     DependencyObject parentObject = GetParentObject(child);

     //we've reached the end of the tree
     if (parentObject == null) return null;

     //check if the parent matches the type we're looking for
     T parent = parentObject as T;
     if (parent != null)
     {
       return parent;
     }
     else
     {
       //use recursion to proceed with next level
       return TryFindParent<T>(parentObject);
     }
   }

   /// <summary>
   /// This method is an alternative to WPF's
   /// <see cref="VisualTreeHelper.GetParent"/> method, which also
   /// supports content elements. Do note, that for content element,
   /// this method falls back to the logical tree of the element!
   /// </summary>
   /// <param name="child">The item to be processed.</param>
   /// <returns>The submitted item's parent, if available. Otherwise
   /// null.</returns>
   public static DependencyObject GetParentObject(DependencyObject child)
   {
     if (child == null) return null;
     ContentElement contentElement = child as ContentElement;

     if (contentElement != null)
     {
       DependencyObject parent = ContentOperations.GetParent(contentElement);
       if (parent != null) return parent;

       FrameworkContentElement fce = contentElement as FrameworkContentElement;
       return fce != null ? fce.Parent : null;
     }

     //if it's not a ContentElement, rely on VisualTreeHelper
     return VisualTreeHelper.GetParent(child);
   }
}
Pituri answered 25/6, 2009 at 9:40 Comment(3)
By convention, I would expect any Try* method to return bool and have an out parameter that returns the type in question, as with: bool IDictionary.TryGetValue(TKey key, out TValue value)Flying
@DrewNoakes what do you suggest Philipp to call it, then? Also, even with such an expectation I find his code both clear and clear to use.Caprine
@ANeves, in this case I would just call it FindParent. This name to me implies that it could return null. The Try* prefix is used throughout the BCL in the way I describe above. Also note that most of the other answers here use the Find* naming convention. It's only a minor point though :)Flying
B
17

I edited CrimsonX's code as it was not working with superclass types:

public static T FindChild<T>(DependencyObject depObj, string childName)
   where T : DependencyObject
{
    // Confirm obj is valid. 
    if (depObj == null) return null;

    // success case
    if (depObj is T && ((FrameworkElement)depObj).Name == childName)
        return depObj as T;

    for (int i = 0; i < VisualTreeHelper.GetChildrenCount(depObj); i++)
    {
        DependencyObject child = VisualTreeHelper.GetChild(depObj, i);

        //DFS
        T obj = FindChild<T>(child, childName);

        if (obj != null)
            return obj;
    }

    return null;
}
Bashibazouk answered 10/6, 2010 at 13:57 Comment(3)
If you pass this method a DependencyObject that is not a FrameworkElement it can throw an Exception. Also using GetChildrenCount on every iteration of the for loop sounds like a bad idea.Incursion
well, this is from 5 years ago, so I don't even know if it works anymore :)Bashibazouk
I just mentioned it, because I stumbled upon it and other could as well ;)Incursion
F
16

Whilst I love recursion in general, it's not as efficient as iteration when programming in C#, so perhaps the following solution is neater than the one suggested by John Myczek? This searches up a hierarchy from a given control to find an ancestor control of a particular type.

public static T FindVisualAncestorOfType<T>(this DependencyObject Elt)
    where T : DependencyObject
{
    for (DependencyObject parent = VisualTreeHelper.GetParent(Elt);
        parent != null; parent = VisualTreeHelper.GetParent(parent))
    {
        T result = parent as T;
        if (result != null)
            return result;
    }
    return null;
}

Call it like this to find the Window containing a control called ExampleTextBox:

Window window = ExampleTextBox.FindVisualAncestorOfType<Window>();
Fadeout answered 6/9, 2011 at 12:31 Comment(0)
Y
10

exciton80... I was having a problem with your code not recursing through usercontrols. It was hitting the Grid root and throwing an error. I believe this fixes it for me:

public static object[] FindControls(this FrameworkElement f, Type childType, int maxDepth)
{
    return RecursiveFindControls(f, childType, 1, maxDepth);
}

private static object[] RecursiveFindControls(object o, Type childType, int depth, int maxDepth = 0)
{
    List<object> list = new List<object>();
    var attrs = o.GetType().GetCustomAttributes(typeof(ContentPropertyAttribute), true);
    if (attrs != null && attrs.Length > 0)
    {
        string childrenProperty = (attrs[0] as ContentPropertyAttribute).Name;
        if (String.Equals(childrenProperty, "Content") || String.Equals(childrenProperty, "Children"))
        {
            var collection = o.GetType().GetProperty(childrenProperty).GetValue(o, null);
            if (collection is System.Windows.Controls.UIElementCollection) // snelson 6/6/11
            {
                foreach (var c in (IEnumerable)collection)
                {
                    if (c.GetType().FullName == childType.FullName)
                        list.Add(c);
                    if (maxDepth == 0 || depth < maxDepth)
                        list.AddRange(RecursiveFindControls(
                            c, childType, depth + 1, maxDepth));
                }
            }
            else if (collection != null && collection.GetType().BaseType.Name == "Panel") // snelson 6/6/11; added because was skipping control (e.g., System.Windows.Controls.Grid)
            {
                if (maxDepth == 0 || depth < maxDepth)
                    list.AddRange(RecursiveFindControls(
                        collection, childType, depth + 1, maxDepth));
            }
        }
    }
    return list.ToArray();
}
Yesima answered 6/6, 2011 at 23:26 Comment(0)
C
9

Here's my code to find controls by Type while controlling how deep we go into the hierarchy (maxDepth == 0 means infinitely deep).

public static class FrameworkElementExtension
{
    public static object[] FindControls(
        this FrameworkElement f, Type childType, int maxDepth)
    {
        return RecursiveFindControls(f, childType, 1, maxDepth);
    }

    private static object[] RecursiveFindControls(
        object o, Type childType, int depth, int maxDepth = 0)
    {
        List<object> list = new List<object>();
        var attrs = o.GetType()
            .GetCustomAttributes(typeof(ContentPropertyAttribute), true);
        if (attrs != null && attrs.Length > 0)
        {
            string childrenProperty = (attrs[0] as ContentPropertyAttribute).Name;
            foreach (var c in (IEnumerable)o.GetType()
                .GetProperty(childrenProperty).GetValue(o, null))
            {
                if (c.GetType().FullName == childType.FullName)
                    list.Add(c);
                if (maxDepth == 0 || depth < maxDepth)
                    list.AddRange(RecursiveFindControls(
                        c, childType, depth + 1, maxDepth));
            }
        }
        return list.ToArray();
    }
}
Carlo answered 20/10, 2010 at 10:17 Comment(0)
K
8

I have a sequence function like this (which is completely general):

    public static IEnumerable<T> SelectAllRecursively<T>(this IEnumerable<T> items, Func<T, IEnumerable<T>> func)
    {
        return (items ?? Enumerable.Empty<T>()).SelectMany(o => new[] { o }.Concat(SelectAllRecursively(func(o), func)));
    }

Getting immediate children:

    public static IEnumerable<DependencyObject> FindChildren(this DependencyObject obj)
    {
        return Enumerable.Range(0, VisualTreeHelper.GetChildrenCount(obj))
            .Select(i => VisualTreeHelper.GetChild(obj, i));
    }

Finding all children down the hiararchical tree:

    public static IEnumerable<DependencyObject> FindAllChildren(this DependencyObject obj)
    {
        return obj.FindChildren().SelectAllRecursively(o => o.FindChildren());
    }

You can call this on the Window to get all controls.

After you have the collection, you can use LINQ (i.e. OfType, Where).

Krutz answered 20/8, 2014 at 15:45 Comment(0)
C
6

Since the question is general enough that it might attract people looking for answers to very trivial cases: if you just want a child rather than a descendant, you can use Linq:

private void ItemsControlItem_Loaded(object sender, RoutedEventArgs e)
{
    if (SomeCondition())
    {
        var children = (sender as Panel).Children;
        var child = (from Control child in children
                 where child.Name == "NameTextBox"
                 select child).First();
        child.Focus();
    }
}

or of course the obvious for loop iterating over Children.

Cuticle answered 6/3, 2011 at 13:3 Comment(0)
A
4

These options already talk about traversing the Visual Tree in C#. Its possible to traverse the visual tree in xaml as well using RelativeSource markup extension. msdn

find by type

Binding="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type <TypeToFind>}}}" 
Ashlynashman answered 2/4, 2015 at 15:4 Comment(0)
I
2

Here is a solution that uses a flexible predicate:

public static DependencyObject FindChild(DependencyObject parent, Func<DependencyObject, bool> predicate)
{
    if (parent == null) return null;

    int childrenCount = VisualTreeHelper.GetChildrenCount(parent);
    for (int i = 0; i < childrenCount; i++)
    {
        var child = VisualTreeHelper.GetChild(parent, i);

        if (predicate(child))
        {
            return child;
        }
        else
        {
            var foundChild = FindChild(child, predicate);
            if (foundChild != null)
                return foundChild;
        }
    }

    return null;
}

You can for example call it like this:

var child = FindChild(parent, child =>
{
    var textBlock = child as TextBlock;
    if (textBlock != null && textBlock.Name == "MyTextBlock")
        return true;
    else
        return false;
}) as TextBlock;
Incursion answered 9/9, 2015 at 15:54 Comment(0)
F
1

To find an ancestor of a given type from code, you can use:

[CanBeNull]
public static T FindAncestor<T>(DependencyObject d) where T : DependencyObject
{
    while (true)
    {
        d = VisualTreeHelper.GetParent(d);

        if (d == null)
            return null;

        var t = d as T;

        if (t != null)
            return t;
    }
}

This implementation uses iteration instead of recursion which can be slightly faster.

If you're using C# 7, this can be made slightly shorter:

[CanBeNull]
public static T FindAncestor<T>(DependencyObject d) where T : DependencyObject
{
    while (true)
    {
        d = VisualTreeHelper.GetParent(d);

        if (d == null)
            return null;

        if (d is T t)
            return t;
    }
}
Flying answered 7/3, 2017 at 12:54 Comment(0)
G
1

I can't find my control with @CrimsonX or @Drew Noakes methods, because my ControlTemplate is located in a separated XAML file. I have found the control using the following method:

private Image backImage;
private void Diagram_Loaded(object sender, System.Windows.RoutedEventArgs e)
{
    // here is the example of the ControlTemplate declaration
    //<ControlTemplate x:Key="DiagramControlTemplate1" TargetType="{x:Type Diagram}">
    var ctrlTemplate = (ControlTemplate)FindResource("DiagramControlTemplate1");
    // diagram is the x:Name of TemplatedControl and, "backImage" is the name of control that I want to find.
    var imageControl = ctrlTemplate.FindName("backImage", diagram);
    if (imageControl != null)
    {
        this.backImage = (Image)imageControl;
    }
}

This is working for me.

Ganges answered 15/3, 2021 at 2:5 Comment(0)
E
0

This code just fixes @CrimsonX answer's bug:

 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;
          }

 // 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
        {
          // child element found.
          foundChild = (T)child;
          break;
        }
      }

      return foundChild;
    }  

You just need to continue calling the method recursively if types are matching but names don't (this happens when you pass FrameworkElement as T). otherwise it's gonna return null and that's wrong.

Erotica answered 21/11, 2017 at 21:17 Comment(1)
This snippet throws an error in VS as currently presented. Downvoting. In short, it lacks a default return state.Harpp
R
0

Here are some methods that I use frequently..

Usage:

// Starts the search from thisUiElement (might be a UserContol, Window, etc..)
var combobox = thisUiElement.ChildOfType<ComboBox>();
var employeesListBox = thisUiElement.ChildOfName("EmployeesListBox");
// Starts the search from MainWindow to find the first DataGrid
var dataGrid = WpfUtils.ChildOfType<DataGrid>();
// Starts the search from MainWindow to find the all ListViews
List<ComboBox> allListViews = WpfUtils.ChildOfType<ListView>();
// Starts the search from MainWindow to find the element of name EmployeesComboBox
var combobox = WpfUtils.ChildOfName("EmployeesComboBox");

Implementation:

/*
using System.Collections.Generic;
using System.Windows;
using System.Windows.Media;

namespace WpfUtilities;
*/

public static class WpfUtils{

    public static Window AppMainWindow =>
        Application.Current?.MainWindow;

    #region Find By Type
    
    // Start the search from MainWindow, example usage: var combobox = WpfUtils.ChildOfType<ComboBox>();
    public static T ChildOfType<T>() where T : DependencyObject =>
        ChildOfType<T>(AppMainWindow);
        
    /// This will return the first child of type T
    public static T ChildOfType<T>(this DependencyObject parent)
        where T : DependencyObject
    {
        if (parent == null) return null;
        T child = default;
        var numVisuals = VisualTreeHelper.GetChildrenCount(parent);
        for (var i = 0; i < numVisuals; i++)
        {
            var v = VisualTreeHelper.GetChild(parent, i);
            child = v as T ?? v.ChildOfType<T>();
            if (child != null)
                break;
        }

        return child;
    }
    
    // Start the search from MainWindow, example usage: List<ComboBox> comboboxes = WpfUtils.ChildOfType<ComboBox>();
    public static IEnumerable<T> ChildrenOfType<T>() where T : DependencyObject =>
        ChildrenOfType<T>(AppMainWindow);
    
    /// This will not break the search when finding the first kid of type T, but it will keep searching to return all kids of type T
    public static IEnumerable<T> ChildrenOfType<T>(
        this DependencyObject parent) where T : DependencyObject
    {
        if (parent == null) yield break;
        var numVisuals = VisualTreeHelper.GetChildrenCount(parent);
        for (var i = 0; i < numVisuals; i++)
        {
            var child = VisualTreeHelper.GetChild(parent, i);
            if (child is T dependencyObject)
                yield return dependencyObject;

            foreach (var childOfChild in child.ChildrenOfType<T>())
                yield return childOfChild;
        }
    }
    
    #endregion  

    #region Find By Name
    
    /// If parent is null, the search will start from MainWindow, example usage: var combobox = WpfUtils.ChildOfName("EmployeesCombobox");
    public static FrameworkElement ChildOfName(string childName,
        DependencyObject parent = null)
    {
        parent ??= AppMainWindow;
        object child = null;
        var numVisuals = VisualTreeHelper.GetChildrenCount(parent);
        for (var i = 0; i < numVisuals; i++)
        {
            var v = VisualTreeHelper.GetChild(parent, i);
            child = v is FrameworkElement f && f.Name == childName
                ? f
                : ChildOfName(childName, v);

            if (child != null)
                break;
        }

        return child as FrameworkElement;
    }
    
    #endregion
    
    #region
    
    // Yet another useful method, if you are writing code in a .xaml.cs file and you want to get the parent of a type.. example usage: this.ParentOfType<Grid>(); this.ParentOfType<UserControl>(); this.ParentOfType<Window>(); 
    public static T ParentOfType<T>(this DependencyObject child) where T : DependencyObject
    {
        var parentDepObj = child;
        do
        {
            parentDepObj = VisualTreeHelper.GetParent(parentDepObj);
            if (parentDepObj is T parent) return parent;
        } while (parentDepObj != null);

        return null;
    }
    
    #endregion
}
Rhamnaceous answered 25/8, 2022 at 5:6 Comment(0)
L
0

To everyone who has trouble FindName of your dynamically generated element... it is because your element was not registered. You need to call RegisterName first.

See: https://learn.microsoft.com/en-us/dotnet/api/system.windows.frameworkelement.registername

Observe the following example, assume a custom control named Hello:

Hello myHello = new Hello();
//myHello.Name = "HelloWorld"; // system doesn't even care
myHello.Visibility = Visibility.Visible;
RegisterName("HelloWorld", myHello);

someGrid.Children.Add(myHello);

With RegisterName, you will be able to find the dynamically generated element.

Note: When using FindName and RegisterName the system doesn't even care about the property Name. IMHO, Name is purely just there for display purposes only in the visual tree.

Lachman answered 11/9, 2023 at 18:10 Comment(0)
S
-2

I was able to find objects by name using below code.

stkMultiChildControl = stkMulti.FindChild<StackPanel>("stkMultiControl_" + couter.ToString());

Spikenard answered 26/12, 2020 at 20:56 Comment(0)
B
-8

Try this

<TextBlock x:Name="txtblock" FontSize="24" >Hai Welcom to this page
</TextBlock>

Code Behind

var txtblock = sender as Textblock;
txtblock.Foreground = "Red"
Blueweed answered 23/3, 2015 at 5:57 Comment(1)
This does not answer I need to search a WPF control hierarchy for controls that match a given name or type. How can I do this?Retrorse

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