Find all controls in WPF Window by type

Question

I m looking for a way to find all controls on Window by their type   for example  find all TextBoxes  find all controls implementing specific interface etc

User · Answer

For some reason  none of the answers posted here helped me to get all controls of given type contained in a given control in my MainWindow       I needed to find all menu items in one menu to iterate them  They were not all direct descendants of the menu  so i managed to collect only the first lilne of them using any of the code above      This extension method is my solution for the problem for anyone who will continue to read all the way down here   public static void FindVisualChildren lt T gt  this ICollection lt T gt  children  DependencyObject depObj  where T   DependencyObject               if  depObj    null                        var brethren   LogicalTreeHelper GetChildren depObj               var brethrenOfType   LogicalTreeHelper GetChildren depObj  OfType lt T gt                 foreach  var childOfType in brethrenOfType                                children Add childOfType                              foreach  var rawChild in brethren                                if  rawChild is DependencyObject                                        var child   rawChild as DependencyObject                      FindVisualChildren lt T gt  children  child                                                     Hope it helps

User · Answer

This is the easiest way   IEnumerable lt myType gt  collection   control Children OfType lt myType gt        where control is the root element of the window

User · Answer

Small change to the recursion to so you can for example find the child tab control of a tab control       public static DependencyObject FindInVisualTreeDown DependencyObject obj  Type type                if  obj    null                        for  int i   0  i  lt  VisualTreeHelper GetChildrenCount obj   i                                  DependencyObject child   VisualTreeHelper GetChild obj  i                    if  child GetType      type                                        return child                                     DependencyObject childReturn   FindInVisualTreeDown child  type                   if  childReturn    null                                        return childReturn                                                     return null

User · Answer

I found it easier without Visual Tree Helpers   foreach  UIElement element in MainWindow Children        if  element is TextBox             if   element as TextBox  Text                                Do something

User · Answer

For this and more use cases you can add flowing extension method to your library   public static List lt DependencyObject gt  FindAllChildren this DependencyObject dpo  Predicate lt DependencyObject gt  predicate                var results   new List lt DependencyObject gt             if  predicate    null              return results            for  int i   0  i  lt  VisualTreeHelper GetChildrenCount dpo   i                          var child   VisualTreeHelper GetChild dpo  i               if  predicate child                   results Add child                var subChildren   child FindAllChildren predicate               results AddRange subChildren                     return results         Example for your case   var children   dpObject FindAllChildren child   gt  child is TextBox

User · Answer

I found that the line  VisualTreeHelper GetChildrenCount depObj    used in several examples above does not return a non-zero count for GroupBoxes  in particular  where the GroupBox contains a Grid  and the Grid contains children elements  I believe this may be because the GroupBox is not allowed to contain more than one child  and this is stored in its Content property  There is no GroupBox Children type of property  I am sure I did not do this very efficiently  but I modified the first  FindVisualChildren  example in this chain as follows     public IEnumerable lt T gt  FindVisualChildren lt T gt  DependencyObject depObj  where T   DependencyObject         if  depObj    null                 int depObjCount   VisualTreeHelper GetChildrenCount depObj            for  int i   0  i  lt depObjCount  i                            DependencyObject child   VisualTreeHelper GetChild depObj  i                if  child    null  amp  amp  child is T                                  yield return  T child                              if  child is GroupBox                                GroupBox gb   child as GroupBox                  Object gpchild   gb Content                  if  gpchild is T                                        yield return  T child                       child   gpchild as T                                               foreach  T childOfChild in FindVisualChildren lt T gt  child                                   yield return childOfChild

User · Answer

I adapted  Bryce Kahle s answer to follow  Mathias Lykkegaard Lorenzen s suggestion and use LogicalTreeHelper    Seems to work okay      public static IEnumerable lt T gt  FindLogicalChildren lt T gt    DependencyObject depObj   where T   DependencyObject       if  depObj    null                 foreach  object rawChild in LogicalTreeHelper GetChildren  depObj                           if  rawChild is DependencyObject                                 DependencyObject child    DependencyObject rawChild                  if  child is T                                         yield return  T child                                     foreach  T childOfChild in FindLogicalChildren lt T gt   child                                            yield return childOfChild                                                       It still won t check tab controls or Grids inside GroupBoxes as mentioned by  Benjamin Berry  amp   David R respectively    Also followed  noonand s suggestion  amp  removed the redundant child    null

User · Answer

Use the helper classes VisualTreeHelper or LogicalTreeHelper depending on which tree you re interested in  They both provide methods for getting the children of an element  although the syntax differs a little   I often use these classes for finding the first occurrence of a specific type  but you could easily modify it to find all objects of that type   public static DependencyObject FindInVisualTreeDown DependencyObject obj  Type type        if  obj    null                if  obj GetType      type                        return obj                     for  int i   0  i  lt  VisualTreeHelper GetChildrenCount obj   i                          DependencyObject childReturn   FindInVisualTreeDown VisualTreeHelper GetChild obj  i   type               if  childReturn    null                                return childReturn                                     return null

User · Answer

I wanted to add a comment but I have less than 50 pts so I can only  Answer   Be aware that if you use the  VisualTreeHelper  method to retrieve XAML  TextBlock  objects then it will also grab XAML  Button  objects   If you re-initialize the  TextBlock  object by writing to the Textblock Text parameter then you will no longer be able to change the Button text using the Button Content parameter   The Button will permanently show the text written to it from the Textblock Text write action  from when it was retrieved --  foreach  TextBlock tb in FindVisualChildren lt TextBlock gt  window        do something with tb here    tb Text         this will overwrite Button Content and render the                     Button Content set  permanently disabled      To work around this  you can try using a XAML  TextBox  and add methods  or Events  to mimic a XAMAL Button  XAML  TextBox  is not gathered by a search for  TextBlock

User · Answer

Do note that using the VisualTreeHelper does only work on controls that derive from Visual or Visual3D  If you also need to inspect other elements  e g  TextBlock  FlowDocument etc    using VisualTreeHelper will throw an exception   Here s an alternative that falls back to the logical tree if necessary   http   www hardcodet net 2009 06 finding-elements-in-wpf-tree-both-ways

User · Answer

This should do the trick  public static IEnumerable lt T gt  FindVisualChildren lt T gt  DependencyObject depObj  where T   DependencyObject       if  depObj    null                for  int i   0  i  lt  VisualTreeHelper GetChildrenCount depObj   i                          DependencyObject child   VisualTreeHelper GetChild depObj  i               if  child    null  amp  amp  child is T                                yield return  T child                             foreach  T childOfChild in FindVisualChildren lt T gt  child                                 yield return childOfChild                                    then you enumerate over the controls like so  foreach  TextBlock tb in FindVisualChildren lt TextBlock gt  window            do something with tb here

User · Answer

And this is how it works upwards      private T FindParent lt T gt  DependencyObject item  Type StopAt  where T   class               if  item is T                        return item as T                    else                       DependencyObject  parent   VisualTreeHelper GetParent item               if   parent    null                                return default T                             else                               Type  type    parent GetType                    if  StopAt    null                                        if    type IsSubclassOf StopAt     true       type    StopAt                                                 return null                                                           if    type IsSubclassOf typeof T      true       type    typeof T                                          return  parent as T                                    else                                       return FindParent lt T gt   parent  StopAt

User · Answer

To get a list of all childs of a specific type you can use   private static IEnumerable lt DependencyObject gt  FindInVisualTreeDown DependencyObject obj  Type type        if  obj    null                if  obj GetType      type                        yield return obj                     for  var i   0  i  lt  VisualTreeHelper GetChildrenCount obj   i                          foreach  var child in FindInVisualTreeDown VisualTreeHelper GetChild obj  i   type                                 if  child    null                                        yield return child                                                       yield break

User · Answer

The accepted answer returns the discovered elements more or less unordered  by following the first child branch as deep as possible  while yielding the discovered elements along the way  before backtracking and repeating the steps for not yet parsed tree branches   If you need the descendent elements in descending order  where the direct children will be yielded first  then their children and so on  the following algorithm will work   public static IEnumerable lt T gt  GetVisualDescendants lt T gt  DependencyObject parent  bool applyTemplates   false      where T   DependencyObject       if  parent    null      child is Visual    child is Visual3D           yield break       var descendants   new Queue lt DependencyObject gt         descendants Enqueue parent        while  descendants Count  gt  0                var currentDescendant   descendants Dequeue             if  applyTemplates               currentDescendant as FrameworkElement   ApplyTemplate             for  var i   0  i  lt  VisualTreeHelper GetChildrenCount currentDescendant   i                          var child   VisualTreeHelper GetChild currentDescendant  i                if  child is Visual    child is Visual3D                  descendants Enqueue child                if  child is T foundObject                  yield return foundObject                      The resulting elements will be ordered from nearest to farthest  This will be useful e g  if you are looking for the nearest child element of some type and condition   var foundElement   GetDescendants lt StackPanel gt  someElement                          FirstOrDefault o   gt  o SomeProperty    SomeState

User · Answer

My version for C   CLI  template  lt  class T  class U  gt  bool Isinst U u         return dynamic cast lt  T  gt  u     nullptr     template  lt typename T gt      T FindVisualChildByType Windows  UI  Xaml  DependencyObject  element  Platform  String  name                if  Isinst lt T gt  element   amp  amp  dynamic cast lt Windows  UI  Xaml  FrameworkElement  gt  element - gt Name    name                        return dynamic cast lt T gt  element                     int childcount   Windows  UI  Xaml  Media  VisualTreeHelper  GetChildrenCount element           for  int i   0  i  lt  childcount    i                        auto childElement   FindVisualChildByType lt T gt  Windows  UI  Xaml  Media  VisualTreeHelper  GetChild element  i   name               if  childElement    nullptr                                return childElement                                  return nullptr

User · Answer

Here is yet another  compact version  with the generics syntax       public static IEnumerable lt T gt  FindLogicalChildren lt T gt  DependencyObject obj  where T   DependencyObject               if  obj    null                if  obj is T                  yield return obj as T               foreach  DependencyObject child in LogicalTreeHelper GetChildren obj  OfType lt DependencyObject gt                      foreach  T c in FindLogicalChildren lt T gt  child                        yield return c

User · Answer

Bryce  really nice answer   VB NET version   Public Shared Iterator Function FindVisualChildren Of T As DependencyObject  depObj As DependencyObject  As IEnumerable Of T      If depObj IsNot Nothing Then         For i As Integer   0 To VisualTreeHelper GetChildrenCount depObj  - 1             Dim child As DependencyObject   VisualTreeHelper GetChild depObj  i              If child IsNot Nothing AndAlso TypeOf child Is T Then                 Yield DirectCast child  T              End If             For Each childOfChild As T In FindVisualChildren Of T  child                  Yield childOfChild             Next         Next     End If End Function   Usage  this disables all TextBoxes in a window            For Each tb As TextBox In FindVisualChildren Of TextBox  Me            tb IsEnabled   False         Next

[c#] Find all controls in WPF Window by type

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