public string GetMaxId()
{
DB db = new DB();
SqlDataReader sdr = null;
string sqlstring = "select Max(AccdId) from AccDetail";
db.RunSQL(sqlstring, out sdr);//这是我写的数据操作类,你自己写
int bit = 0;
string accdid="";
if (sdr.Read())
{
if (String.IsNullOrEmpty(sdr[0].ToString()))
{
accdid = "000000001";
}
else
{
bit = Convert.ToInt32(sdr[0].ToString().Substring(3)) + 1;