diff --git a/src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Input/Command/CommandBinding.cs b/src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Input/Command/CommandBinding.cs
index 0890cda14..02acc51b5 100644
--- a/src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Input/Command/CommandBinding.cs
+++ b/src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Input/Command/CommandBinding.cs
@@ -7,6 +7,7 @@
 
 using System;
 using System.ComponentModel;
+using System.Diagnostics;
 using System.Windows;
 using System.Windows.Markup;
 using MS.Internal; 
@@ -60,18 +61,13 @@ public CommandBinding(ICommand command, ExecutedRoutedEventHandler executed)
         /// <param name="canExecute">Handler associated with determining if the command can execute.</param>
         public CommandBinding(ICommand command, ExecutedRoutedEventHandler executed, CanExecuteRoutedEventHandler canExecute)
         {
-            if (command == null)
-            {
-                throw new ArgumentNullException("command");
-            }
+            _command = command ?? throw new ArgumentNullException(nameof(command));
 
-            _command = command;
-
-            if (executed != null)
+            if (executed is not null)
             {
                 Executed += executed;
             }
-            if (canExecute != null)
+            if (canExecute is not null)
             {
                 CanExecute += canExecute;
             }
@@ -87,20 +83,8 @@ public CommandBinding(ICommand command, ExecutedRoutedEventHandler executed, Can
         [Localizability(LocalizationCategory.NeverLocalize)] // cannot be localized        
         public ICommand Command
         {
-            get     
-            { 
-                return _command;
-            }
-
-            set     
-            {
-                if (value == null)
-                {
-                    throw new ArgumentNullException("value");
-                }
-
-                _command = value; 
-            }
+            get => _command;
+            set => _command = value ?? throw new ArgumentNullException(nameof(value));
         }
 
         #endregion
@@ -138,49 +122,46 @@ public ICommand Command
         /// <param name="e">Event arguments.</param>
         internal void OnCanExecute(object sender, CanExecuteRoutedEventArgs e)
         {
-            if (!e.Handled)
+            if (e.Handled) return;
+            if (e.RoutedEvent == CommandManager.CanExecuteEvent)
             {
-                if (e.RoutedEvent == CommandManager.CanExecuteEvent)
+                if (CanExecute is null)
                 {
-                    if (CanExecute != null)
-                    {
-                        CanExecute(sender, e);
-                        if (e.CanExecute)
-                        {
-                            e.Handled = true;
-                        }
-                    }
-                    else if (!e.CanExecute)
-                    {
-                        // If there is an Executed handler, then the command can be executed.
-                        if (Executed != null)
-                        {
-                            e.CanExecute = true;
-                            e.Handled = true;
-                        }
-                    }
+                    if (e.CanExecute) return;
+                    // If there is an Executed handler, then the command can be executed.
+                    if (Executed is null) return;
+                    e.CanExecute = true;
+                    e.Handled = true;
                 }
-                else // e.RoutedEvent == CommandManager.PreviewCanExecuteEvent
+                else
                 {
-                    if (PreviewCanExecute != null)
+                    CanExecute(sender, e);
+                    if (e.CanExecute)
                     {
-                        PreviewCanExecute(sender, e);
-                        if (e.CanExecute)
-                        {
-                            e.Handled = true;
-                        }
+                        e.Handled = true;
                     }
                 }
             }
+            else // e.RoutedEvent == CommandManager.PreviewCanExecuteEvent
+            {
+                if (PreviewCanExecute is null) return;
+                PreviewCanExecute(sender, e);
+                if (e.CanExecute)
+                {
+                    e.Handled = true;
+                }
+            }
         }
 
         private bool CheckCanExecute(object sender, ExecutedRoutedEventArgs e)
         {
-            CanExecuteRoutedEventArgs canExecuteArgs = new CanExecuteRoutedEventArgs(e.Command, e.Parameter);
-            canExecuteArgs.RoutedEvent = CommandManager.CanExecuteEvent;
+            CanExecuteRoutedEventArgs canExecuteArgs = new(e.Command, e.Parameter)
+            {
+                RoutedEvent = CommandManager.CanExecuteEvent,
+                // Since we don't actually raise this event, we have to explicitly set the source.
+                Source = e.OriginalSource
+            };
 
-            // Since we don't actually raise this event, we have to explicitly set the source.
-            canExecuteArgs.Source = e.OriginalSource;
             canExecuteArgs.OverrideSource(e.Source);
             
             OnCanExecute(sender, canExecuteArgs);
@@ -195,30 +176,22 @@ private bool CheckCanExecute(object sender, ExecutedRoutedEventArgs e)
         /// <param name="e">Event arguments.</param>
         internal void OnExecuted(object sender, ExecutedRoutedEventArgs e)
         {
-            if (!e.Handled)
+            if (e.Handled) return;
+            if (e.RoutedEvent == CommandManager.ExecutedEvent)
             {
-                if (e.RoutedEvent == CommandManager.ExecutedEvent)
-                {
-                    if (Executed != null)
-                    {
-                        if (CheckCanExecute(sender, e))
-                        {
-                            Executed(sender, e);
-                            e.Handled = true;
-                        }
-                    }
-                }
-                else // e.RoutedEvent == CommandManager.PreviewExecutedEvent
-                {
-                    if (PreviewExecuted != null)
-                    {
-                        if (CheckCanExecute(sender, e))
-                        {
-                            PreviewExecuted(sender, e);
-                            e.Handled = true;
-                        }
-                    }
-                }
+                if (Executed is null) return;
+                if (!CheckCanExecute(sender, e)) return;
+                Debug.Assert(Executed != null, nameof(Executed) + " != null");
+                Executed(sender, e);
+                e.Handled = true;
+            }
+            else // e.RoutedEvent == CommandManager.PreviewExecutedEvent
+            {
+                if (PreviewExecuted is null) return;
+                if (!CheckCanExecute(sender, e)) return;
+                Debug.Assert(PreviewExecuted != null, nameof(PreviewExecuted) + " != null");
+                PreviewExecuted(sender, e);
+                e.Handled = true;
             }
         }
 
diff --git a/src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Input/Command/CommandBindingCollection.cs b/src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Input/Command/CommandBindingCollection.cs
index 98725d642..8adf9e4d2 100644
--- a/src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Input/Command/CommandBindingCollection.cs
+++ b/src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Input/Command/CommandBindingCollection.cs
@@ -52,9 +52,9 @@ public CommandBindingCollection()
         /// <param name="commandBindings">CommandBinding array</param>
         public CommandBindingCollection(IList commandBindings)
         {
-            if (commandBindings != null && commandBindings.Count > 0)
+            if (commandBindings is { Count: > 0 })
             {
-                AddRange(commandBindings as ICollection);
+                AddRange(commandBindings);
             }
         }
 
@@ -76,12 +76,9 @@ public CommandBindingCollection(IList commandBindings)
         /// </summary>
         /// <param name="array">commandbinding array to copy into</param>
         /// <param name="index">start index in current list to copy</param>
-        void ICollection.CopyTo(System.Array array, int index) 
+        void ICollection.CopyTo(System.Array array, int index)
         {
-            if (_innerCBList != null)
-            {
-                ((ICollection)_innerCBList).CopyTo(array, index);
-            }
+            ((ICollection)_innerCBList)?.CopyTo(array, index);
         }
   
 #endregion Implementation of ICollection
@@ -92,7 +89,7 @@ void ICollection.CopyTo(System.Array array, int index)
         /// <returns>true - if found, false - otherwise</returns>
         bool IList.Contains(object key) 
         {
-             return this.Contains(key as CommandBinding) ;
+             return Contains(key as CommandBinding) ;
         }
 
         /// <summary>
@@ -102,8 +99,7 @@ bool IList.Contains(object key)
         /// <returns></returns>
         int IList.IndexOf(object value)
         {
-            CommandBinding commandBinding = value as CommandBinding;
-            return ((commandBinding != null) ? this.IndexOf(commandBinding) : -1);
+            return ((value is CommandBinding commandBinding) ? IndexOf(commandBinding) : -1);
         }
 
         /// <summary>
@@ -113,7 +109,7 @@ int IList.IndexOf(object value)
         /// <param name="value">item to insert</param>
         void IList.Insert(int index, object value)
         {
-            this.Insert(index, value as CommandBinding);
+            Insert(index, value as CommandBinding);
         }
 
         /// <summary>
@@ -122,7 +118,7 @@ void IList.Insert(int index, object value)
         /// <param name="commandBinding">CommandBinding object to add</param>
         int IList.Add(object commandBinding) 
         {
-            return this.Add(commandBinding as CommandBinding);
+            return Add(commandBinding as CommandBinding);
         }
         
         /// <summary>
@@ -131,7 +127,7 @@ int IList.Add(object commandBinding)
         /// <param name="commandBinding">CommandBinding object to remove</param>
         void IList.Remove(object commandBinding)
         {
-            this.Remove(commandBinding as CommandBinding);
+            Remove(commandBinding as CommandBinding);
         }
 
         /// <summary>
@@ -145,8 +141,7 @@ object IList.this[int index]
             }
             set 
             {
-                CommandBinding commandBinding = value as CommandBinding;
-                if (commandBinding == null)
+                if (value is not CommandBinding commandBinding)
                     throw new NotSupportedException(SR.Get(SRID.CollectionOnlyAcceptsCommandBindings));
 
                 this[index] = commandBinding;
@@ -160,7 +155,7 @@ public CommandBinding  this[int index]
         {
             get
             {
-                return (_innerCBList != null ? _innerCBList[index] : null);
+                return (_innerCBList?[index]);
             }
             set
             {
@@ -179,8 +174,7 @@ public int Add(CommandBinding commandBinding)
         {
             if (commandBinding != null)
             {
-                if (_innerCBList == null)
-                    _innerCBList = new System.Collections.Generic.List<CommandBinding>(1);
+                _innerCBList ??= new Collections.Generic.List<CommandBinding>(1);
 
                 _innerCBList.Add(commandBinding);
                 return 0; // ICollection.Add no longer returns the indice
@@ -200,27 +194,23 @@ public int Add(CommandBinding commandBinding)
         public void AddRange(ICollection collection) 
         {
             if (collection==null)
-                throw new ArgumentNullException("collection");
-            
-            if (collection.Count > 0) 
-            {
-                 if (_innerCBList == null)
-                    _innerCBList = new System.Collections.Generic.List<CommandBinding>(collection.Count);
+                throw new ArgumentNullException(nameof(collection));
+
+            if (collection.Count <= 0) return;
+            _innerCBList ??= new System.Collections.Generic.List<CommandBinding>(collection.Count);
 
-                IEnumerator collectionEnum = collection.GetEnumerator();
-                while(collectionEnum.MoveNext()) 
+            IEnumerator collectionEnum = collection.GetEnumerator();
+            while(collectionEnum.MoveNext()) 
+            {
+                if (collectionEnum.Current is CommandBinding cmdBinding)
                 {
-                    CommandBinding cmdBinding = collectionEnum.Current as CommandBinding;
-                    if (cmdBinding != null)
-                    {
-                        _innerCBList.Add(cmdBinding);
-                    }
-    	            else
-            	    {
-                    	throw new NotSupportedException(SR.Get(SRID.CollectionOnlyAcceptsCommandBindings));
-                    }
-                 }
-             }
+                    _innerCBList.Add(cmdBinding);
+                }
+                else
+                {
+                    throw new NotSupportedException(SR.Get(SRID.CollectionOnlyAcceptsCommandBindings));
+                }
+            }
         }
 
         /// <summary>
@@ -232,8 +222,7 @@ public void Insert(int index, CommandBinding commandBinding)
         {
             if (commandBinding != null)
             {
-                if (_innerCBList != null)
-                    _innerCBList.Insert(index, commandBinding);
+                _innerCBList?.Insert(index, commandBinding);
             }
             else
             {
@@ -257,8 +246,7 @@ public void Remove(CommandBinding commandBinding)
         /// <param name="index">index at which the item needs to be removed</param>
         public void RemoveAt(int index)
         {
-            if (_innerCBList != null)
-                _innerCBList.RemoveAt(index);
+            _innerCBList?.RemoveAt(index);
         }
 
         /// <summary>
@@ -276,11 +264,7 @@ public bool IsSynchronized
         {
             get
             {
-                if (_innerCBList != null)
-                {
-                    return ((IList)_innerCBList).IsSynchronized;
-                }
-                return false;
+                return _innerCBList is not null && ((IList)_innerCBList).IsSynchronized;
             }
         }
 
@@ -310,7 +294,7 @@ public int Count
         {
             get 
             {
-                return (_innerCBList != null ? _innerCBList.Count : 0);
+                return _innerCBList?.Count ?? 0;
             }
         }
 
@@ -319,11 +303,9 @@ public int Count
         /// </summary>
         public void Clear()
         {
-            if (_innerCBList != null)
-            {
-                _innerCBList.Clear();
-                _innerCBList = null;
-            }
+            if (_innerCBList is null) return;
+            _innerCBList.Clear();
+            _innerCBList = null;
         }
 
         /// <summary>
@@ -333,7 +315,7 @@ public void Clear()
         /// <returns></returns>
         public int IndexOf(CommandBinding value)
         {
-            return ((_innerCBList != null) ? _innerCBList.IndexOf(value) : -1);
+            return _innerCBList?.IndexOf(value) ?? -1;
         }
 
         /// <summary>
@@ -355,10 +337,9 @@ public bool Contains(CommandBinding commandBinding)
         /// </summary>
         /// <param name="commandBindings"> type-safe (CommandBinding) array</param>
         /// <param name="index">start index in current list to copy</param>
-        public void CopyTo(CommandBinding[] commandBindings, int index) 
+        public void CopyTo(CommandBinding[] commandBindings, int index)
         {
-            if (_innerCBList != null)
-                _innerCBList.CopyTo(commandBindings, index);
+            _innerCBList?.CopyTo(commandBindings, index);
         }
 
 #region Implementation of Enumerable
@@ -385,17 +366,11 @@ internal ICommand FindMatch(object targetElement, InputEventArgs inputEventArgs)
             for (int i = 0; i < Count; i++)
             {
                 CommandBinding commandBinding = this[i];
-                RoutedCommand routedCommand = commandBinding.Command as RoutedCommand;
-                if (routedCommand != null)
+                if (commandBinding.Command is not RoutedCommand routedCommand) continue;
+                InputGestureCollection inputGestures = routedCommand.InputGesturesInternal;
+                if (inputGestures?.FindMatch(targetElement, inputEventArgs) != null)
                 {
-                    InputGestureCollection inputGestures = routedCommand.InputGesturesInternal;
-                    if (inputGestures != null)
-                    {
-                        if (inputGestures.FindMatch(targetElement, inputEventArgs) != null)
-                        {
-                            return routedCommand;
-                        }
-                    }
+                    return routedCommand;
                 }
             }
 
@@ -423,7 +398,7 @@ internal CommandBinding FindMatch(ICommand command, ref int index)
         //
         //------------------------------------------------------
 #region Private Fields
-        private System.Collections.Generic.List<CommandBinding>  _innerCBList;
+        private Collections.Generic.List<CommandBinding>  _innerCBList;
 #endregion Private Fields
     }
 }
diff --git a/src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Input/Command/CommandManager.cs b/src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Input/Command/CommandManager.cs
index 1434794fb..3a0454e32 100644
--- a/src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Input/Command/CommandManager.cs
+++ b/src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Input/Command/CommandManager.cs
@@ -601,64 +601,56 @@ internal static void OnCommandDevice(object sender, CommandDeviceEventArgs e)
         private static void FindCommandBinding(object sender, RoutedEventArgs e, ICommand command, bool execute)
         {
             // Check local command bindings
-            CommandBindingCollection commandBindings = null;
-            DependencyObject senderAsDO = sender as DependencyObject;
-            if (InputElement.IsUIElement(senderAsDO))
+            CommandBindingCollection commandBindings = sender switch
             {
-                commandBindings = ((UIElement)senderAsDO).CommandBindingsInternal;
-            }
-            else if (InputElement.IsContentElement(senderAsDO))
-            {
-                commandBindings = ((ContentElement)senderAsDO).CommandBindingsInternal;
-            }
-            else if (InputElement.IsUIElement3D(senderAsDO))
-            {
-                commandBindings = ((UIElement3D)senderAsDO).CommandBindingsInternal;
-            }
-            if (commandBindings != null)
+                UIElement uiElement => uiElement.CommandBindingsInternal,
+                ContentElement contentElement => contentElement.CommandBindingsInternal,
+                UIElement3D uiElement3d => uiElement3d.CommandBindingsInternal,
+                _ => default
+            };
+            if (commandBindings is not null)
             {
                 FindCommandBinding(commandBindings, sender, e, command, execute);
             }
 
+            Type senderType = sender.GetType();
+
             // If no command binding is found, check class command bindings
             // First find the relevant command bindings, under the lock.
             // Most of the time there are no such bindings;  most of the rest of
             // the time there is only one.   Lazy-allocate with this in mind.
-            Tuple<Type, CommandBinding> tuple = null;       // zero or one binding
-            List<Tuple<Type, CommandBinding>> list = null;  // more than one
-
+            ValueTuple<Type, CommandBinding>? tuple = default;       // zero or one binding
+            List<ValueTuple<Type, CommandBinding>> list = default;   // more than one
+            
             lock (_classCommandBindings.SyncRoot)
             {
                 // Check from the current type to all the base types
-                Type classType = sender.GetType();
-                while (classType != null)
+                Type classType = senderType;
+                while (classType is not null)
                 {
-                    CommandBindingCollection classCommandBindings = _classCommandBindings[classType] as CommandBindingCollection;
-                    if (classCommandBindings != null)
+                    if (_classCommandBindings[classType] is CommandBindingCollection classCommandBindings)
                     {
                         int index = 0;
                         while (true)
                         {
                             CommandBinding commandBinding = classCommandBindings.FindMatch(command, ref index);
-                            if (commandBinding != null)
+                            if (commandBinding is null)
                             {
-                                if (tuple == null)
-                                {
-                                    tuple = new Tuple<Type, CommandBinding>(classType, commandBinding);
-                                }
-                                else
-                                {
-                                    if (list == null)
-                                    {
-                                        list = new List<Tuple<Type, CommandBinding>>();
-                                        list.Add(tuple);
-                                    }
-                                    list.Add(new Tuple<Type, CommandBinding>(classType, commandBinding));
-                                }
+                                break;
+                            }
+
+                            if (tuple is null)
+                            {
+                                tuple = ValueTuple.Create(classType, commandBinding);
                             }
                             else
                             {
-                                break;
+                                list ??= new List<ValueTuple<Type, CommandBinding>>(8)
+                                {
+                                    // We know that tuple cannot be null here
+                                    tuple.Value
+                                };
+                                list.Add(new ValueTuple<Type, CommandBinding>(classType, commandBinding));
                             }
                         }
                     }
@@ -668,37 +660,35 @@ private static void FindCommandBinding(object sender, RoutedEventArgs e, IComman
 
             // execute the bindings.  This can call into user code, so it must
             // be done outside the lock to avoid deadlock.
-            if (list != null)
+            if (list is not null)
             {
                 // more than one binding
-                ExecutedRoutedEventArgs exArgs = execute ? (ExecutedRoutedEventArgs)e : null;
-                CanExecuteRoutedEventArgs canExArgs = execute ? null : (CanExecuteRoutedEventArgs)e;
-                for (int i=0; i<list.Count; ++i)
+                ExecutedRoutedEventArgs exArgs = execute ? (ExecutedRoutedEventArgs)e : default;
+                CanExecuteRoutedEventArgs canExArgs = execute ? default : (CanExecuteRoutedEventArgs)e;
+                for (int i = 0; i < list.Count; ++i)
                 {
                     // invoke the binding
-                    if ((execute && ExecuteCommandBinding(sender, exArgs, list[i].Item2)) ||
-                        (!execute && CanExecuteCommandBinding(sender, canExArgs, list[i].Item2)))
+                    if ((!execute || !ExecuteCommandBinding(sender, exArgs, list[i].Item2)) &&
+                        (execute || !CanExecuteCommandBinding(sender, canExArgs, list[i].Item2))) continue;
+                    // if it succeeds, advance past the remaining bindings for this type
+                    Type classType = list[i].Item1;
+                    while (++i < list.Count && list[i].Item1 == classType)
                     {
-                        // if it succeeds, advance past the remaining bindings for this type
-                        Type classType = list[i].Item1;
-                        while (++i<list.Count && list[i].Item1 == classType)
-                        {
-                            // no body needed
-                        }
-                        --i;    // back up, so that the outer for-loop advances to the right place
+                        // no body needed
                     }
+                    --i;    // back up, so that the outer for-loop advances to the right place
                 }
             }
-            else if (tuple != null)
+            else if (tuple is var (_, commandBinding))
             {
                 // only one binding
                 if (execute)
                 {
-                    ExecuteCommandBinding(sender, (ExecutedRoutedEventArgs)e, tuple.Item2);
+                    ExecuteCommandBinding(sender, (ExecutedRoutedEventArgs)e, commandBinding);
                 }
                 else
                 {
-                    CanExecuteCommandBinding(sender, (CanExecuteRoutedEventArgs)e, tuple.Item2);
+                    CanExecuteCommandBinding(sender, (CanExecuteRoutedEventArgs)e, commandBinding);
                 }
             }
         }
@@ -709,15 +699,20 @@ private static void FindCommandBinding(CommandBindingCollection commandBindings,
             while (true)
             {
                 CommandBinding commandBinding = commandBindings.FindMatch(command, ref index);
-                if ((commandBinding == null) ||
-                    (execute && ExecuteCommandBinding(sender, (ExecutedRoutedEventArgs)e, commandBinding)) ||
-                    (!execute && CanExecuteCommandBinding(sender, (CanExecuteRoutedEventArgs)e, commandBinding)))
+                if (HandleCommandBinding(sender, e, commandBinding, execute))
                 {
                     break;
                 }
             }
         }
 
+        private static bool HandleCommandBinding(object sender, RoutedEventArgs e, CommandBinding commandBinding, bool execute)
+        {
+            return commandBinding is null ||
+                   execute && ExecuteCommandBinding(sender, (ExecutedRoutedEventArgs)e, commandBinding) ||
+                   !execute && CanExecuteCommandBinding(sender, (CanExecuteRoutedEventArgs)e, commandBinding);
+        }
+
         private static void TransferEvent(IInputElement newSource, CanExecuteRoutedEventArgs e)
         {
             RoutedCommand command = e.Command as RoutedCommand;