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 = 0; 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 = 0; 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;
}