private void DelRole()
        {
            TreeNode _node = this.tvRole.SelectedNode;

            if (_node == null)
            {
                return;
            }

            if ((_node.Tag as Role).ID == "roleadmin")
            {
                MessageBox.Show("该角色为系统默认角色,不能删除!", "提示");
                return;
            }

            if (MessageBox.Show("是否要删除该角色?", "提示", MessageBoxButtons.YesNo, MessageBoxIcon.Question, MessageBoxDefaultButton.Button2) == DialogResult.No)
            {
                return;
            }

            if (_node.Nodes.Count > 0)
            {
                MessageBox.Show("该角色有子角色,不能删除");
                return;
            }

            try
            {
                PrivilegeService _proxy = Common.Util.CreateProxy();
                using (_proxy as IDisposable)
                {
                    try
                    {
                        FrameWork.Management.PublicTrans.BeginTransaction();
                        _proxy.RemoveRole(_node.Tag as Role);
                        FrameWork.Management.PublicTrans.Commit();
                    }
                    catch (Exception e)
                    {
                        FrameWork.Management.PublicTrans.RollBack();
                        throw e;
                    }
                }
            }
            catch (Exception e)
            {
                MessageBox.Show(e.Message, "提示");
                return;
            }

            _node.Parent.Nodes.Remove(_node);
        }