1,、用文件記錄,，每次訪問文件：死鎖問題嚴(yán)重，資源耗費(fèi)太大,。
2,、用數(shù)據(jù)庫記錄：訪問損耗大。
3,、用Global.asax和Timer實(shí)現(xiàn)統(tǒng)計(jì)：比較可取,。
下面舉個(gè)例子：
總的來說，要做個(gè)在線人數(shù)統(tǒng)計(jì)簡單,，但是要做在線名單并且保存用戶的訪問日志,，就需要耗費(fèi)比較多的系統(tǒng)資源，是否劃算就難說了（我只看需求文檔,，其他不管...）,；
前面用過的IHttpModule方法也不錯(cuò)
using System;
using System.ComponentModel;
using System.Web;
using System.Web.SessionState;
using System.Data;
using System.Data.OleDb;
namespace Butterfly{
/// <summary>
/// Global 的摘要說明。
/// </summary>
public class Global : System.Web.HttpApplication
{
private static System.Threading.Timer timer;
private const int interval = 1000 * 60 * 10;//檢查在線用戶的間隔時(shí)間
/// <summary>
/// 必需的設(shè)計(jì)器變量,。
/// </summary>
private System.ComponentModel.IContainer components = null;
public Global()
{
InitializeComponent();
}
protected void Application_Start(Object sender, EventArgs e)
{
if (timer == null)
timer = new System.Threading.Timer(new System.Threading.TimerCallback(ScheduledWorkCallback),
sender, 0, interval);
DataTable userTable = new DataTable();
userTable.Columns.Add("UserID");//用戶ID
userTable.Columns.Add("UserName");//用戶姓名
userTable.Columns.Add("FirstRequestTime");//第一次請求的時(shí)間
userTable.Columns.Add("LastRequestTime");//最后一次請求的時(shí)間
userTable.Columns.Add("ClientIP");//
userTable.Columns.Add("ClientName");//
userTable.Columns.Add("ClientAgent");//
//userTable.Columns.Add("LastRequestPath");//最后訪問的頁面
userTable.PrimaryKey = new DataColumn[]{userTable.Columns[0]};
userTable.AcceptChanges();
Application.Lock();
Application["UserOnLine"] = userTable;
Application.UnLock();
}
protected void Session_Start(Object sender, EventArgs e)
{
}
protected void Application_BeginRequest(Object sender, EventArgs e)
{
}
protected void Application_EndRequest(Object sender, EventArgs e)
{
}
protected void Application_AcquireRequestState(Object sender, EventArgs e)
{
HttpApplication mApp = (HttpApplication)sender;
if(mApp.Context.Session == null) return;
if(mApp.Context.Session["UserID"]==null ) return;
string userID = mApp.Context.Session["UserID"].ToString();
DataTable userTable = (DataTable)Application["UserOnLine"];
DataRow curRow = userTable.Rows.Find(new object[]{userID});
if(curRow != null)
{
this.GetDataRowFromHttpApp(mApp,ref curRow);
}
else
{
DataRow newRow = userTable.NewRow();
this.GetDataRowFromHttpApp(mApp,ref newRow);
userTable.Rows.Add(newRow);
}
userTable.AcceptChanges();
Application.Lock();
Application["UserOnLine"] = userTable;
Application.UnLock();
}
protected void Application_AuthenticateRequest(Object sender, EventArgs e)
{
}
protected void Application_Error(Object sender, EventArgs e)
{
}
protected void Session_End(Object sender, EventArgs e)
{
}
protected void Application_End(Object sender, EventArgs e)
{
}
#region Web 窗體設(shè)計(jì)器生成的代碼
/// <summary>
/// 設(shè)計(jì)器支持所需的方法 - 不要使用代碼編輯器修改
/// 此方法的內(nèi)容,。
/// </summary>
private void InitializeComponent()
{
this.components = new System.ComponentModel.Container();
}
#endregion
private void GetDataRowFromHttpApp(HttpApplication mApp,ref DataRow mRow)
{
if(mApp.Context.Session == null) return;
if(mApp.Context.Session["UserID"]==null || mApp.Context.Session["UserName"]==null) return;
string userID = mApp.Context.Session["UserID"].ToString();
string userName = mApp.Context.Session["UserName"].ToString();
//string requestPath = mApp.Request.Path;
if(mRow["UserID"].ToString().Length<1)
{
mRow["UserID"] = userID;
mRow["UserName"] = userName;
mRow["FirstRequestTime"] = System.DateTime.Now;
mRow["ClientIP"] = mApp.Context.Request.UserHostAddress;
mRow["ClientName"] = mApp.Context.Request.UserHostName;
mRow["ClientAgent"] = mApp.Context.Request.UserAgent;
}
mRow["LastRequestTime"] = System.DateTime.Now;
//mRow["LastRequestPath"] = requestPath;
}
private void ScheduledWorkCallback (object sender)
{
string filter = "Convert(LastRequestTime,‘System.DateTime‘) < Convert(‘" + System.DateTime.Now.AddSeconds(-interval/1000).ToString() + "‘,‘System.DateTime‘)";
DataTable userTable = (DataTable)Application["UserOnLine"];
DataRow[] lineOutUsers = userTable.Select(filter);
for(int i=0;i<lineOutUsers.Length;i++)
{
DataRow curRow = lineOutUsers[i];
//保存到數(shù)據(jù)庫
curRow.Delete();
}
userTable.AcceptChanges();
Application.Lock();
Application["UserOnLine"] = userTable;
Application.UnLock();
}
}
}
補(bǔ)充：
在線人數(shù)比較好做，在線名單就不好做了,，
另外,，<sessionState> 設(shè)為InProc方式時(shí)才可以觸發(fā)SessionEnd事件，其它
Off 指示會(huì)話狀態(tài)未啟用,。
StateServer 指示在遠(yuǎn)程計(jì)算機(jī)上存儲會(huì)話狀態(tài),。
SQLServer 指示在 SQL Server 上存儲會(huì)話狀態(tài)。
幾種方式就不能觸發(fā)SessionEnd事件；
無論以何種解決方案,，都很難做到準(zhǔn)確,，就像QQ，對方掉線了,，你也只能過一會(huì)才知道
