private void GridView1_ItemClick(object sender, GridViewCellItemEventArgs e)
        {
            if (isGroup == true)
            {
                getGroupuserCount();
            }
            else
            {
                string userid = e.Cell.Items["lblUSER_ID"].Text;
                if (string.IsNullOrEmpty(userid) == false)
                {
                    //添加用户
                    string token = im.CreateUser(userid, userid, ".\\Image\\" + e.Cell.Items["imgPortraitUri"].DefaultValue + ".PNG");
                    if (im != null)
                    {
                        //添加联系人到数据库

                        MessageBox.Show("联系人已添加", (Object s, MessageBoxHandlerArgs args) => Bind());
                    }
                    else
                    {
                        Toast("联系人添加失败");
                    }
                }
            }
        }