string strID ="NODE_aSDFghsdfgyuhjidfgh_45678" //得到_ 中间的数
int index = strID.IndexOf("_");
int namelength = strID.Length;
string id = strID.Substring(index, strID.Length - index);
//id = id.Substring(1, id.Length - 4);
string strStar = id.Substring(1);
int li_Index = strStar.LastIndexOf("_");
string ls_New = strStar.Substring(0, li_Index);//获得目标字符串