Web Forms :: Static Variables Throughout Application
Oct 6, 2010
i am developing a website in asp.net i have created a class "Utility" in App_Code Folder this class contains a static object of another class(LoginInfo) as described below:
[Code]....
This LoginInfo Class is my business object which only contains 2 properties UserID and UserName
Now what i am doing on my login page, after user authentication i am setting these properties with current logged in UserId and UserName
[Code]....
I am using this CurrentUser object on my webpage to get userid and username. It works fine, but after few minutes my CurrentUser.UserID and CurrentUser.UserName is set to blank string. I am not able to figure out what is the problem. may be due to asp.net recycles.
whats the exact use of static variables in overall programming in .net and for asp.net...
Recently i went for the interview where interviewer asked me 2 question which i was not sure for the same..
whats the use of session object, i said sessions are the server side object, they are used when you want to store user specific data at server side, then he asked what if i want to use static variables for the same, i was mum, can anyone tell me how asp.net will behave if i store the user specific information in static variables.If i use cookies which are the best option to store the data at client side (not sensitive one), but what if user has disabled cookies on his machine, will my application would crash.
I know what they are and how they are used but i am not sure about their feasibility. Their use is always advised to be avoided. can some one explain me when they should be used and when not?
Aif i have a choice between static veriable and session for just storing an integer which one of these should i prefer??
I have some WCF services. These services run in ASP.NET. I want these services to be able to access a static variable. My problem is, I'm not sure where the appropriate server level storage mechanism is. I don't want to use the database because of speed. But, I want the static variables to stay in memory as long as possible. In fact, I'd like it to stay until I restart my server if it all possible.
If I declare a static field in a type instantiated within an ASP.NET application, hosted within IIS, is the same variable (i.e. same memory location) used by all of the worker threads used by IIS, opening up concurrency issues?
Possible Duplicate: Where are static variables stored in asp.net aspx page Hi can someone please tell me where the static variables are stored in asp.net aspx page.Is it in the view state? If so I guess you wouldn't want to stored big complex objects?
public static void TryOut(int intOne, int intTwo, string strone, string strtwo){....}
And after I created dll, I will use it like that;
TryOut(1,3,"bla bla bla", "bla bla bla"); But I want the last variable to be optional. I mean this method could be used like that; TryOut(1,3,"bla bla bla", "bla bla bla"); And Also like that TryOut(1,3,"bla bla bla");
I know it is possibel but how I could do that I have no idea !
For reasons I would rather not discuss, I need to create a custom authentication system for my app. I was just reviewing the system and am having some doubts if my solution is thread safe. My goal was to create a solution that would allow my app to authenticate a user one time and that users authentication info would be shared by all master pages, pages, classes, user controls, etc that are used. (But not share the same info between users) Here is my setup: PageHttpModule.cs - this is added to the web.config as a httpModule.
public class PageHttpModule : IHttpModule { public void Init(HttpApplication app) { app.AuthenticateRequest += new EventHandler(OnAuthenticateRequest); } public void OnAuthenticateRequest(Object s, EventArgs e) { CurrentUser.Initialize(); } public void Dispose() { } } CurrentUser.cs public static class CurrentUser { public static bool IsAuthenticated { get; private set; } public static string Email {get; set;} public static string RealName {get; set; public static string UserId {get; set;} public static void Initialize() { CurrentUser.AuthenticateUser(); } Note: this is a scaled down version of my authentication code. public static void AuthenticateUser() { UserAuthentication user = new UserAuthentication(); user.AuthenticateUser(); if (user.IsAuthenticated) { CurrentUser.IsAuthenticated = true; CurrentUser.UserId = user.UserId; CurrentUser.Email = user.Email; CurrentUser.RealName = user.RealName; } } } UserAuthentication.cs public class UserAuthentication { public string Email { get; set; } public string RealName { get; set; } public string UserId { get; set; } public bool IsAuthenticated { get; private set; } public UserAuthentication() { IsAuthenticated = false; Email = String.Empty; RealName = String.Empty; UserId = String.Empty; } public void AuthenticateUser() { //do some logic here.. if the user is ok then IsAuthenticated = true Email = address from db UserId = userid from db; Realname = name from db; } }
I have tested between 3 different browsers and it seems to work fine, but I am still learning and don't want to make a huge mistake. If my logic is totally wrong, then how should I do it so I dont have to put user lookups on every page directly?
is there any way to stop share the static variable at multiple users....I need to create a new insatnce of static variables or not accessing the same static variables across multiple who are using the same site.....while googling i found like hisSystem.Threading.Interlocked.Increment(ref MyClass.InstanceCounter); by using can I do....or is there any other way to stop accessing the static variables accross multiple instances of my site......and in my scenario i cannot use rely on session variable also
im developing a silverlight project using silverlight 3, vs2008 and linq2sql. when projects starts, im storing all the data from database into some static list variables. so when ever i need data, im reading it from those static list variables. all i want to know is, is it good to store data in static list variables and use it when ever necessary or is it good to get data directly from DataClassesDataContext object like db.mytable. which is the rite and fastest way or retrieving data. i mean which will use less connections to database?
So I started working on my first asp.net application that involves logging in and databases, and soon after i started messing around with a static class. I "discovered" that if you make a variable static, all sessions share that variable (I for some reason was originally assuming that each session had its own copy of that "static" class). Anyway, after discovering this I thought to myself "how could this possibly be useful to me" and thought that itmight be a good idea to make a single static database connection for all of the sessions, rather than storing that as a session variable for each session. Does anybody know what would be the pros and cons of this approach?
I'm coding a business layer for an ASP.NET application. I've created database methods in my BLL as static. I've created public static Func variables to be compiled and used in several different methods, like this:
namespace BLL public class User { public static Func<Context, variable, result> selectUser; private static void CompileQuery() { if(selectUser == null) { selectUser = CompiledQuery.Compile...... } } public static UserClass Select(int id) { CompileQuery(); //uses selectUser } public static SomethingElse DoSomethingElse() { CompileQuery(); //also uses selectUser } }
It'll be used in ASP.NET layer like this: using BLL;
private void AddUser() { UserClass user = User.Select(id); }
My question is, since static variables are not thread-safe, is this a bad design decision? I'm thinking of either implementing a locking mechanism, which makes me think if it'd slow down the application, or using instantiated class approach which makes me wonder if query compiling would be beneficial.
I'm developing a server control and I'd like to set some cache and application level variables but I don't want them to be visible from outside the control. Is this possible?
While understanding the basic concept of inheritance in internet, i came across a piece of code.
I've seen many people using public static void main().Why dont they simply use public void main() ??What's the advantage of using static here ?
Public class BaseClass { Public BaseClass () { Console.WriteLine ("Base Class Constructor executed"); } Public void Write () { Console.WriteLine ("Write method in Base Class executed");
If I have a 2 control load events and one page load event subs and the control1_Load events fires first, can I lookup some database things and persist them? I would like to use the persisted data in the other two events when they fire. Normally I've been using session variables , is there a better way?
I cant figure out how to use the Application["myvar"] variable to store data for the application in asp.net 4.0 web app using c#. It say Application is not a known object and I can't for the life of me figure what to do a "using" on to expose it. I am in a static class at the time I cant use it. It seems to work in other units?
This question actually refers to a classic ASP page I'm working on, but I'm assuming that app variables work the same in both ASP and ASP.NET Let's say we have a bunch of websites, owned by different people. The sites are all different, but the common theme is they are car enthusiast websites. Each of these websites has their own unique index page (of course), but also "common" pages, which are pages shared by all the websites.
One of the common pages, checks for the value of an application variable, which may or may not exist. For example, lets call this page luxurycars.asp, which is a simple page that shows the top 10 luxury cars of this year. This common luxury car page will pull and use the app variable like so:
[CODE] Dim SiteOwner SiteOwner = Application("OwnerName") Response.Write("This site is managed by " & SiteOwner) [/CODE]
This app variable is set uniquely in each clients index.asp page like so:
Will this work? I just started learning classic ASP (for my job), and I'm reading that application variables are universal and only one copy of the variable will exist. So does this mean if John Doe sets Application("OwnerName") to "John Doe" in HIS index.asp page, will everyone that visits the common luxury car page see John Doe's name? Regardless of whether they got to that page via John Doe's page or someone elses? And if so would using a Session variable instead solve this problem? Sorry if this sounds confusing, let me know if I need to re-word it or give more detail...
I store a large structure holding my application's reference data in a variable I access through HttpContext.Application. Every once in a while this data needs to change. When I update it in place, is there a danger that incoming requests will see the data in an inconsistent state? Is there a need (and a way) to lock some or all of this structure? Finally, are there other approaches to this problem other than querying the database every time you need this (mostly static) data?
I understand the problem of the static variable inside a class in the web application, now I try to create a simple class to deal with SQL Server for example, so I created Static Method inside this class, this static method used in insert, update and delete from database, I wonder if this is safe, and there is no problems will appear ?
I haven't used the application variables in my asp.net web applications. Im using asp.net2.0. Is there any disadvantages of using applicationvariables.
