QQ互发消息

  private NewsData data;
        private void button3_Click(object sender, EventArgs e) //发送
        {
            string x = textBox1.Text; //将输入框的内容存到x里面
            new NewsDA().Insert(x);//然后将x存到数据库里面去
            textBox1.Text = "";//清空一下原来的输入框
            data = new NewsDA().Select1();//调用一个查询方法 ，查一下刚刚存到数据库里的数据
            if(data!=null)
            {
                textBox2.Text = textBox2.Text  + "\r\n" + data.Neirong;//将查到的刚存到数据库的数据放到右边的文本框里
            }

        }
        private List<NewsData> sss;
        private string y;
        private void timer1_Tick(object sender, EventArgs e) //定时执行事件
        {
            sss = new NewsDA().Select2(); //查一下对方发过来的信息（也是先存到数据库，但是是另外一个表里），然后定时查询
            //if(sss!=null)              //定时查询后每次都存到左边的文本框里
            //{
            //    textBox3.Text = sss[i].Neirong;
            //}
            if (sss != null)
            {
                for (int i = ; i < sss.Count; i++)
                {
                    y = sss[i].Neirong; //查出来的内容
                }
            }
            textBox3.Text = y;

        }

---------------------------------另一个对话框的代码一样，只是查询的各自的表相反

private NewsData data;
        private void button1_Click(object sender, EventArgs e) //发送
        {
            string x = textBox1.Text; //将输入框的文本存到x里面
            new NewsDA().Insertagain(x);//将x存到数据库里面
            textBox1.Text = "";
            data = new NewsDA().Select4();
            if (data != null)
            {
                textBox2.Text = textBox2.Text  + "\r\n" + data.Neirong;
            }
        }
  private void timer1_Tick(object sender, EventArgs e) //定时执行事件
        {
            string zqqq = "";
           List<NewsData> s =new NewsDA().Select5();//查一下自己发过去的消息
            if(s!=null)
            {
           for (int i = ; i < s.Count; i++)
           {
                zqqq = s[i].Neirong;//查到之后显示在左边的文本框里
           }
           textBox3.Text = zqqq;
            }
        }
    }

-------------下面是NewsDA 大部分都一样，写的很乱。其实就几个，有一些是没用的

 public class NewsDA
    {
        private SqlConnection Conn;
        private SqlCommand Cmd;

        public NewsDA()
        {
            Conn = new SqlConnection("server=.;database=Tencent;user=sa;pwd=123");
           Cmd = Conn.CreateCommand();
        }
        public void Insert(string x)
        {

            Conn.Open();
            Cmd.CommandText = "insert into news values(@z)";
            Cmd.Parameters.Clear();
            Cmd.Parameters.Add("@z",x);
            Cmd.ExecuteNonQuery();
            Cmd.Dispose();
            Conn.Close();

        }
        public void Insertagain(string x)
        {

            Conn.Open();
            Cmd.CommandText = "insert into newsagain values(@z)";
            Cmd.Parameters.Clear();
            Cmd.Parameters.Add("@z", x);
            Cmd.ExecuteNonQuery();
            Cmd.Dispose();
            Conn.Close();

        }
        public List<NewsData> Select()
        {
            List<NewsData> list = null;
            Conn.Open();
            Cmd.CommandText = "select * from news";
            SqlDataReader dr = Cmd.ExecuteReader();
            if (dr.HasRows)
            {
                list = new List<NewsData>();
                while (dr.Read())
                {
                    NewsData s = new NewsData();
                    s.Neirong = dr["neirong"].ToString();
                    list.Add(s);
                }
            }
            return list;
        }
        public NewsData Select1()
        {
            NewsData list = null;
            Conn.Open();
            Cmd.CommandText = "select * from news";
            SqlDataReader dr = Cmd.ExecuteReader();
            if (dr.HasRows)
            {
                list = new NewsData();
                while (dr.Read())
                {

                    list.Neirong = dr["neirong"].ToString();

                }
            }
            return list;
        }
        public List<NewsData> Select2()
        {
            List<NewsData> list = null;
            Conn.Open();
            Cmd.CommandText = "select* from newsagain";
            SqlDataReader dr = Cmd.ExecuteReader();
            if (dr.HasRows)
            {
                list = new List<NewsData>();
                while (dr.Read())
                {
                    NewsData a = new NewsData();
                    a.Neirong = dr["neirong"].ToString();
                    list.Add(a);

                }
            }
            return list;
        }
        public NewsData Select3()
        {
            NewsData list = null;
            Conn.Open();
            Cmd.CommandText = "select top 1* from newsagain order by ids desc";
            SqlDataReader dr = Cmd.ExecuteReader();
            if (dr.HasRows)
            {
                list = new NewsData();
                while (dr.Read())
                {

                    list.Neirong = dr["neirong"].ToString();

                }
            }
            return list;
        }
        public NewsData Select4()
        {
            NewsData list = null;
            Conn.Open();
            Cmd.CommandText = "select * from newsagain ";
            SqlDataReader dr = Cmd.ExecuteReader();
            if (dr.HasRows)
            {
                list = new NewsData();
                while (dr.Read())
                {

                    list.Neirong = dr["neirong"].ToString();

                }
            }
            return list;
        }
        public List<NewsData> Select5()
        {
            List<NewsData> list = null;
            Conn.Open();
            Cmd.CommandText = "select* from news";
            SqlDataReader dr = Cmd.ExecuteReader();
            if (dr.HasRows)
            {
                list = new List<NewsData>();
                while (dr.Read())
                {
                    NewsData a = new NewsData();
                    a.Neirong = dr["neirong"].ToString();
                    list.Add(a);

                }
            }
            return list;
        }
        public void Delete1(string ids)
        {

            Conn.Open();
            Cmd.CommandText = "delete from news where ids='"+ids+"'";
            Cmd.ExecuteReader();
            Cmd.Dispose();
            Conn.Close();

        }
        public void Deleteagain()
        {

            Conn.Open();
            Cmd.CommandText = "delete from newsagain ";
            Cmd.ExecuteReader();
            Cmd.Dispose();
            Conn.Close();

        }
        public void Delete2(string ids)
        {

            Conn.Open();
            Cmd.CommandText = "delete from newsagain where ids='" + ids + "'";
            Cmd.ExecuteReader();
            Cmd.Dispose();
            Conn.Close();

        }
        public void Delete()
        {

            Conn.Open();
            Cmd.CommandText = "delete from news";
           Cmd.ExecuteReader();
           Cmd.Dispose();
           Conn.Close();

        }

        //第二个
        public NewsData Selectagain()
        {
            NewsData list = null;
            Conn.Open();
            Cmd.CommandText = "select * from newsagain";
            SqlDataReader dr = Cmd.ExecuteReader();
            if (dr.HasRows)
            {
                list = new NewsData();
                while (dr.Read())
                {

                    list.Neirong = dr["neirong"].ToString();

                }
            }
            return list;
        }