The number of online people and the number of historical visitors to the site

L'm from Http://hi.baidu.com/mydelicious/blog/item/22b10d38cb14ef25b8998fbb.html.

Prepare for Work 1, create a new Tongji database, add a Tongji table with a number field in the table, an int type, Numger initial value of 1000; 2, create a new Web site, 3, create a new database connection string (< connectionstrings> <add name= "tongjiconnectionstring" connectionstring= "Data source=.;i Nitial catalog=tongji;integrated security=true "providername= System.Data.SqlClient"/> </connectionstrings >

Key code 4, add New Item/Global Application class: Global.asax, the full code of its file is as follows:

<%@ application Language= "C #"%>

<%@ Import namespace= "System.Data.SqlClient"%>

<script runat= "Server" > void Application_Start (object sender, EventArgs e)

{

Code that runs when the application starts

SqlConnection con = new SqlConnection ();

Con. ConnectionString = configurationmanager.connectionstrings["tongjiconnectionstring"]. ConnectionString;

Con. Open ();

SqlCommand cmd = new SqlCommand ("SELECT * from Tongji", con);

int count = Convert.ToInt32 (cmd. ExecuteScalar ());

Con. Close ();

application["Total" = count;

application["Online"] = 0; }

void Application_End (object sender, EventArgs e)

{//code to run when the application shuts down

SqlConnection con = new SqlConnection (); Con. connectionstring=configurationmanager.connectionstrings["Tongjiconnectionstring"]. ConnectionString;

Con. Open ();

SqlCommand cmd = new SqlCommand ("Update Tongji set number=" + application["Total"). ToString (), con);

Cmd. ExecuteNonQuery ();

Con.     Close (); }

void Application_Error (object sender, EventArgs e)

{//code to run when an unhandled error occurs}

void Session_Start (object sender, EventArgs e)

{//Code Application.Lock () to run when a new session starts;

application["Total"] = (int) application["Total"] + 1;

application["Online"] = (int) application["online" + 1;

Application.UnLock (); }

void Session_End (object sender, EventArgs e)

{//code that runs at the end of the session.

Application.Lock ();

application["Online"] = (int) application["Online"]-1;

Application.UnLock (); }

</script>

Run Test 5,

Drag two lable to Default.aspx;

6, its Default.ASPx.cs code as follows: public partial class _default:system.web.ui.page

{protected void Page_Load (object sender, EventArgs e)

{

This. Label1.Text = "Total number of visitors" + application["sum"]. ToString ();

This. Label2.Text = "Current online number" + application["on-line"]. ToString ();

}

}

7, OK. Start Debugging.

Note 8, I in the VS2005 debugging, show: Total number of visitors to 1001; current online number of 1 when;       I reopened another IE, and the address copy past, then show: Total number of visitors to 1002; current online number 2; This shows that everything is fine.       However, the database is still 1000,。。。。。。       I was here to delay a lot of time (a day), but in my despair, I tried more than once, however, this time Providence gave me unexpected gifts.       At this point, I am in VS2005, "File" menu, choose "Save Global", at this time, 1000 of the database is not updated to 1002. If debugging is the same in I I S, the data is written to the database only if you shut down or stop the WWW service normally.