Asp.net利用Application与Session统计网站在线人数和访问总人数

Asp.net利用Application与Session统计网站在线人数和访问总人数

protected void Application_Start(Object sender, EventArgs e)
  {
   SqlConnection con=new SqlConnection("server=localhost;database=countPeople;uid=sa;pwd=sa;");
   con.Open();
   SqlCommand cmd=new SqlCommand("select * from countPeople",con);
   int count=Convert.ToInt32(cmd.ExecuteScalar());
   con.Close();
   Application["totol"]=count;
   Application["online"]=0;
  }
 
  protected void Session_Start(Object sender, EventArgs e)
  {
   Session.Timeout=1;
   Application.Lock();
   Application["totol"]=(int)Application["totol"]+1;
   Application["online"]=(int)Application["online"]+1;
   Application.UnLock();

  }

protected void Session_End(Object sender, EventArgs e)
  {
   Application.Lock();
   Application["online"]=(int)Application["online"]-1;
   Application.UnLock();
  }

  protected void Application_End(Object sender, EventArgs e)
  {
   SqlConnection con=new SqlConnection("server=localhost;database=countPeople;uid=sa;pwd=sa;");
   con.Open();
   SqlCommand cmd=new SqlCommand("update countPeople set num=" + Application["totol"].ToString(),con);
   cmd.ExecuteNonQuery();
   con.Close();
  }

Application.Lock();

锁定Application对象,   别的进程必须等UNLOCK后才能更新Application内容.防止两个进程同时修改APPLICATION内容.