private void Form1_Load(object sender, EventArgs e)
        {
            string comstring = "select Towaste from Con";
            SqlDataAdapter com = new SqlDataAdapter(comstring,DBHelp.connection);
            DataSet ds=new DataSet();
            com.Fill(ds, "Con");
            this.dataGridView1.DataSource = ds.Tables["Con"];

        }
这一句怎么用循环读出 Towaste 的值！

foreach(DataRow dr in ds.Tables["Con"].Rows)//循环行
{
   Response.Write(dr["Towaste"].ToString());
}

支持楼上！
也可以直接循环你的dataGridView1
按你绑定的Towaste所在列进行循环查看