treelist学习总结 --拖拽事件

来源：互联网发布：硬盘安装mac os x 编辑：程序博客网时间：2024/05/21 06:44

1.2关于拖拽

树节点的拖拽事件，一般用三个，dragDrop,dragEnter,dragOver分别是有拖拽趋向时发生，拖拽了以后发生，拖拽动作结束发生。以下是我写的拖拽事件。

仅供参考，

//关于拖拽事件还有一个属性，optionsbehavior.dragnodes如果等于 false就是不允许拖拽了

#region drag 事件

        private void treeDepartment_DragDrop(object sender, DragEventArgs e)
        {
            TreeListNode targetNode =GetNodeByLocation(this, new Point(e.X, e.Y));
            bool succeed = DoDragDrop(e, targetNode);

            if (succeed && !GetDraggedNode(e).TreeList.Equals(this))
            {
                this.Refresh();
            }
        }

        private void treeDepartment_DragEnter(object sender, DragEventArgs e)
        {
            UiCommon.SetDragEffect(e, GetNodeByLocation(this, new Point(e.X, e.Y)));

}

        private void treeDepartment_DragOver(object sender, DragEventArgs e)
        {
            UiCommon.SetDragEffect(e, GetNodeByLocation(this, new Point(e.X, e.Y)));
        }

#endregion

        /// <summary>
        /// 根据鼠标位置获取节点
        /// </summary>
        /// <param name="treeList">节点所在的treelist</param>
        /// <param name="location">节点位置</param>
        /// <returns></returns>
        private TreeListNode GetNodeByLocation(TreeList treeList, Point location)
        {
            TreeListHitInfo hitInfo = treeList.CalcHitInfo(treeList.PointToClient(location));
            return hitInfo.Node;
        }

/// <summary>
        /// 拖拽事件
        /// </summary>
        /// <param name="e"></param>
        /// <param name="targetNode"></param>
        /// <returns></returns>
        private bool DoDragDrop(DragEventArgs e, TreeListNode targetNode)
        {
            if (e.Effect != DragDropEffects.Move)
                return false;
            TreeListNode draggedNode = GetDraggedNode(e);

            DataRow draggedRow = draggedNode.Tag as DataRow;
            if (draggedRow == null)
                return false;
            DataRow targetRow = targetNode.Tag as DataRow;
            if (targetRow == null)
                return false;
            string tableName = draggedRow.Table.TableName;
            return DragDepartment(draggedRow, targetRow);
        }

// <summary>
        /// 移动部门位置
        /// </summary>
        /// <param name="draggedRow"></param>
        /// <param name="targetRow"></param>
        /// <returns></returns>
        private static bool DragDepartment(DataRow draggedRow, DataRow targetRow)
        {
            string departmentName = "";
            try
            {
                string targetTableName = targetRow.Table.TableName;
                departmentName = draggedRow["DeptName"].ToString();
                if (!targetTableName.Equals("DepartmentTable", StringComparison.CurrentCultureIgnoreCase))
                    return false;

DepartmentInfoAccessor.MoveDepartment(draggedRow["DeptID"].ToString(),
targetRow["DeptID"].ToString());

                return true;
            }
            catch (Exception ex)
            {

               return false;
            }
        }

/// <summary>
        /// 设置拖拽时的鼠标效果
        /// </summary>
        /// <param name="e"></param>
        /// <param name="targetNode"></param>
        internal static void SetDragEffect(DragEventArgs e, TreeListNode targetNode)
        {
            TreeListNode draggedNode = GetDraggedNode(e);
            DataRow draggedRow = (DataRow)draggedNode.Tag;

            //当被拖动的节点无法处理时显示禁止图标
            if (draggedRow == null ||
                (!draggedRow.Table.TableName.Equals("UserTable", StringComparison.CurrentCultureIgnoreCase) &&
                !draggedRow.Table.TableName.Equals("DepartmentTable", StringComparison.CurrentCultureIgnoreCase)))
            {
                e.Effect = DragDropEffects.None;
                return;
            }

            //当不存在目标节点或目标节点的层级大于等于被拖动节点时（后者仅针对树内拖拽），显示禁止图标
            if (targetNode == null || draggedNode == targetNode || targetNode.HasAsParent(draggedNode))
            {
                e.Effect = DragDropEffects.None;
                return;
            }

e.Effect = DragDropEffects.Move;
}