using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlClient;
using DB;
using System.Threading;namespace SourceReadDemo
{
    class Class1
    {
        private bool flag;//用于关闭线程
        private bool flag1;
        private Thread thread1;
        private Thread thread;//定义一个线程
        
        SqlConnection con = new SqlConnection("server=.;database=pubs;uid=sa;pwd=");
        DataSet dss = new DataSet();//声明全局的dataset
        public void start()
        {
            //启动线程
            flag = true;
            flag1 = true;
            thread = new Thread(new ThreadStart(threadProc(sql)));//当前上下文中不存在名称“sql” ????
            thread1 = new Thread(new ThreadStart(threa1(ds)));当前上下文中不存在名称“ds”
            thread.Start();
            thread1.Start();
            thread.Priority = ThreadPriority.Highest;//将读数据线程优先        }
        ////线程回调函数
        private void threadProc()
        {
            while (flag)
            {                DataBind(sql);)));//当前上下文中不存在名称“sql” ????
                Thread.Sleep(100);
            }
        }
        private void threa1()
        {
            while (flag1)
            {
                qu(ds);)));//当前上下文中不存在名称“ds” ????
                Thread.Sleep(1000);
            }        }
        public DataSet DataBind(string sql)
        {            try
            {                SqlDataAdapter sdat = new SqlDataAdapter(sql, con);
                sdat.Fill(dss,"student");
            }
            catch (Exception e)
            {
                MessageBox.Show(e.Message);
            }
            finally
            {
                con.Close();            }
            return null;
        }
        public DataSet qu(DataSet ds)
        {
           // DataSet ds = new DataSet();
            try
            {
                if (ds.Tables["student"].Rows.Count != 0)
                {
                    MessageBox.Show("发送数据");
                    return ds;
    
                }
                else
                {
                    MessageBox.Show("数据已经没有了");
                    flag = false;
                    flag1 = false;
                    return null;
                }
              
                
            }
            catch (Exception x)
            {
                MessageBox.Show(("等待数秒后请按‘确定’"));
            }
            return ds;
        }
    }
}
该怎么把他改好啊?
  谢谢帮忙