添加项目文件。

Commands/ScrollViewerCommand.cs

@@ -0,0 +1,37 @@
+using System.Windows.Input;
+
+namespace YwxApp.AiChat.Commands
+{
+  
+    /// <summary>
+    /// Scroll command : The argument object passed by this constructor of this class is ScrollViewer
+    /// </summary>
+    class ScrollViewerCommand : ICommand
+    {
+        private readonly Action<object> _execute;
+        private readonly Predicate<object> _canExecute;
+
+        public ScrollViewerCommand(Action<object> execute, Predicate<object> canExecute = null)
+        {
+            _execute = execute ?? throw new ArgumentNullException(nameof(execute));
+            _canExecute = canExecute;
+        }
+
+        public bool CanExecute(object parameter)
+        {
+            return _canExecute == null || _canExecute(parameter);
+        }
+
+        public void Execute(object parameter)
+        {
+            _execute(parameter);
+        }
+
+        public event EventHandler CanExecuteChanged
+        {
+            add { CommandManager.RequerySuggested += value; }
+            remove { CommandManager.RequerySuggested -= value; }
+        }
+    }
+}
+