dt.AcceptChanges();//SetModified()需要
for (int i = 0; i < dt.Rows.Count; i++)
{
dt.Rows[i].SetModified();//无此标记默认新插入行到数据库
dt.Rows[i]["xx"] = "xx"
}
//表需要有主键
SqlDataAdapter datp = new SqlDataAdapter(string.Format("select * from {0} ", TableName), SqlConn);//SqlConn连接字符串
SqlCommandBuilder cmd = new System.Data.SqlClient.SqlCommandBuilder(datp);
datp.Update(dt);