wpf listbox 或grid 界面模拟滑动效果行为

using System.Windows;
using System.Windows.Controls;
using System.Windows.Interactivity;
using System.Windows.Media;
using System.Windows.Controls.Primitives;

namespace TC_Client.Games.BBWP
{
    public class ListScrollBehavior : Behavior<UIElement>
    {
        /// <summary>
        /// 当元素绑定行为以后
        /// </summary>
        protected override void OnAttached()
        {
            base.OnAttached();

            if (this.AssociatedObject is ListBox)
            {
                this.AssociatedObject.AddHandler(ListBox.MouseLeftButtonDownEvent, new System.Windows.Input.MouseButtonEventHandler(AssociatedObject_MouseLeftButtonDown), true);
            }
            else if (this.AssociatedObject is DataGrid)
            {
                this.AssociatedObject.AddHandler(DataGrid.MouseLeftButtonDownEvent, new System.Windows.Input.MouseButtonEventHandler(AssociatedObject_MouseLeftButtonDown), true);
            }
            else if (this.AssociatedObject is Border)
            {
                this.AssociatedObject.AddHandler(Border.MouseLeftButtonDownEvent, new System.Windows.Input.MouseButtonEventHandler(AssociatedObject_MouseLeftButtonDown), true);
            }
            else
            {
                this.AssociatedObject.MouseLeftButtonDown += new System.Windows.Input.MouseButtonEventHandler(AssociatedObject_MouseLeftButtonDown);
            }
            this.AssociatedObject.MouseMove += new System.Windows.Input.MouseEventHandler(AssociatedObject_MouseMove);
            this.AssociatedObject.MouseLeftButtonUp += new System.Windows.Input.MouseButtonEventHandler(AssociatedObject_MouseLeftButtonUp);
        }

        #region 滚动逻辑

        /// <summary>
        /// 是否按下
        /// </summary>
        private bool isDragging = false;

        /// <summary>
        /// 按下时的位置
        /// </summary>
        private Point mouseOffset;

        /// <summary>
        /// 滚动条
        /// </summary>
        private ScrollViewer scroll;

        private void AssociatedObject_MouseLeftButtonDown(object sender, System.Windows.Input.MouseButtonEventArgs e)
        {
            //if (e.MouseDevice.Captured is ButtonBase)
            //{
            //    return;
            //}
            isDragging = true;
            mouseOffset = e.GetPosition(this.AssociatedObject);
            if (this.scroll == null)
            {
                this.scroll = FindVisualChild<ScrollViewer>(this.AssociatedObject);
            }
        }

        private void AssociatedObject_MouseMove(object sender, System.Windows.Input.MouseEventArgs e)
        {
            if (this.isDragging && e.LeftButton == System.Windows.Input.MouseButtonState.Pressed)
            {
                Point newPoint = e.GetPosition(this.AssociatedObject);
                if (newPoint.Y - mouseOffset.Y > 30)
                {
                    scroll.LineUp();
                    mouseOffset = newPoint;
                }
                else if (newPoint.Y - mouseOffset.Y < -30)
                {
                    scroll.LineDown();
                    mouseOffset = newPoint;
                }
            }
        }

        private void AssociatedObject_MouseLeftButtonUp(object sender, System.Windows.Input.MouseButtonEventArgs e)
        {
            if (this.isDragging)
            {
                this.isDragging = false;
            }
        }

        public static T FindVisualChild<T>(DependencyObject obj) where T : DependencyObject
        {
            if (obj != null)
            {
                for (int i = 0; i < VisualTreeHelper.GetChildrenCount(obj); i++)
                {
                    DependencyObject child = VisualTreeHelper.GetChild(obj, i);
                    if (child != null && child is T)
                    {
                        return (T)child;
                    }
                    T childItem = FindVisualChild<T>(child);
                    if (childItem != null) return childItem;
                }
            }
            return null;
        }

        #endregion 滚动逻辑

        protected override void OnDetaching()
        {
            base.OnDetaching();

            this.AssociatedObject.MouseLeftButtonDown -= AssociatedObject_MouseLeftButtonDown;
            this.AssociatedObject.MouseMove -= AssociatedObject_MouseMove;
            this.AssociatedObject.MouseLeftButtonUp -= AssociatedObject_MouseLeftButtonUp;
        }
    }
}