Vb.net - Architecture Specific To Shared/Static Functions?
Apr 30, 2010
If for example you have a function Public shared function GetStockByID(StockID as Guid) as Stock Is that function common to all current users of your application? Or is the shared function only specific to the current user and shared in the context of ONLY that current user? So more specifically my question is this, besides database concurrency issues such as table locking do I need to concern myself with threading issues in shared functions in an ASP.Net application?In my head; let's say my application namespace is MyTestApplicationNamespace. Everytime a new user connects to my site a new instance of the MyTestApplicationNamespace is created and therefore all shared functions are common to that instance and user but NOT common across multiple users. Is this correct?
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Aug 20, 2010
I get this error: Cannot refer to an instance member of a class from within a shared method or shared member initializer without an explicit instance of the class.
Partial Class _Default
Inherits System.Web.UI.Page
<WebMethod()> _
Public Shared Function ParseData() As String
Dim value as string = GetValue()
End Function
Private Function GetValue() as String
Return "halp"
End Function
End Class
I know it has something to do with the fact that the first function is shared and the second function should probably be Public as well but I don't fully understand the reason behind it. Probably not relevant but I'm calling the web method from some javascript.
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Oct 4, 2010
I have some code in my new asp.net app that I need to share. So i created a shared class called
"utilities.vb" and put it in the APP_CODE folder. There is a function I have in there that pulls a person's image based off of their MemberId.
[Code]....
And I can call this function from my page using utilities.FcnGetMemberImage(). Ok, so all good so far until it complains about...
"Cannot refer to an instance member of a class from within a shared method or shared member initializer without an explicit instance of the class"
when referring to the Server.MapPath()
But the problem is that if I don't make it a Shared Function, I can't access it from my other pages. But if I do make it a Shared Function, it throws this error. The fix is supposed to be that I either don't share the function, or
"add the shared keyword to the member declaration", according to Microsoft at
http://msdn.microsoft.com/en-us/library/xfsswe45.aspx
But I'm not exactly sure how to "add the shared keyword to the member declaration" or what this means exactly and how this might affect other parts of my code?
Or is there a better way to work around this dilemma?
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Jan 8, 2010
We have an application that has quite an extensive APP_Code directory (about 150 functions). The functions are split across multiple files and then classes and namespaces.
On numerous pages we have to create numerous instances of the classes to be able to access the functionality, which can get very repetitive and means we're repeating code on every page declaring the instance etc.
As far as I can tell, a way to navigate this issue, is to make the functions Public Shared (as opposed to just Public functions).
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Jan 21, 2011
I have a member function that does not depend on any member variables of the class. (in my case the class is an ASP.Net Page)
The function is protected, I dont need it outside of this class. Its only purpose is to build an URL from an given object.
Should I make all my functions static if they dont depend on the class, even if they are not used outside of this class?
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Mar 5, 2011
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.
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May 7, 2010
I'm building an online system to be used by school groups. Only one school can log into the system at any one time, and from that school you'll get about 13 users. They then proceed into a educational application in which they have to co-operate to complete tasks, and from a code point of view, sharing variables all over the place.
I was thinking, if I set up a static class with static properties that hold the variables that are required to be shared, this could save me having to store/access the variables in/from a database, as long as the static variables are all properly initialized when the application starts and cleaned up at the end. Of course I would also have to put locks on the get and set methods to make the variables thread safe.
Something in the back of my mind is telling me this might be a terrible way of going about things, but I'm not sure exactly why, so if people could give me their thoughts for or against using a static class in this situation,
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Mar 4, 2010
I have a base class with several derived classes. I want all of my derived classes to have the same Public Shared (static) method with their own implementation. How do I do this?
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Nov 11, 2010
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?
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Sep 16, 2010
my understanding static/shared objects will be saved in a memory that is shared by all instances of the asp.net application,so if we set a value to shared object from inst1 & i should be able to access it via instance2(may be in same computer or anywhere)Actually:In my vb.net application,previously they defined shared dataset to hold some information specific to the user,still now i cant reproduce the error that same value shared across all application instances.Please help me to solve or clarify this.
[URL]
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Dec 4, 2010
I am using silverlight, vs 2010, and need to write some basic functions.
Some of the functions are getting a string and find if it's odd or even, and some of them getting status from database.What is the best way doing so : Javascript, ASP.NET, AJAX?
Need an example of code, that also include some dlls/assemblies,
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Mar 13, 2011
I've created a function to generate a sitemap of all of my content, and what I'd like to do is update the sitemap every day at midnight, or once a week for example.
How should I go about getting this done?
My website will be hosted in a shared environment if that's significant.
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Apr 28, 2010
I dont know if im writing in a right place. this is about class in App_Data (asp.net) folder that i want to user throughout system. but specifically for one user.
lets say userA login to the system. then system will use classUser
FillProperty and set variable like Name, Username, UserId (a property of his own, the modifier is
shared). the purpose is so that it can be used in any page. it behaves like
user.identity.name (when we want to call name of user that already authenticated)
I can do it fine. but once i test login with UserB in other browser, it change that shared variable with property of userB.what i want is, when A login, he will set the classUser with his data and data that called by him is his data. and when B login, he will do the same, but he will use his data without replacing userA data.here is the code :
-------------- CLASS -------------[Code]....
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May 26, 2010
so I see these opinions/tutorials about serving static content to support views, from files that co-reside in directories with those views:http://forums.asp.net/p/1258895/2347379.aspx#2347379http://haacked.com/archive/2008/06/25/aspnetmvc-block-view-access.aspxIn the second article, Phil says view-adjacent static content was default-enabled at the time (over a year ago). Unfortunately, though, I reference:
[Code]....
and by default ASP.NET is trying to find it adjacent to my view, which (voila!) is disabled by default. Grr. :)What is the out-of-box IDE-assisted way to reference view-specific static content that doesn't require hardcoding directory tree structures into my path, and also doesn't require ALL of my assets to be in a single folder?Or, if I do it the "unpure" way like I'll probably do if I don't get other ideas (by modifying /Views/Web.Config HttpFileNotFoundHandler), should I block anything unsafe besides .ASCX, .ASPX, and .MASTER that is likely to show up in my views folder?
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May 28, 2010
In page behind classes I am using a private and shared object (list<client> or just client) to temporary hold data coming from database or class library. This object is used temporarily to catch data and than to return, pass to some function or binding acontrol. 1st: Can this approach harm any way ? I couldnt analyse it but a thought was using such shared variables may replace data in it ?2nd: Please comment also on using such variables in BLL (to hold data coming from database) where new object of BLL class will be made everytime.
[Code]....
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Jan 5, 2010
I have designed an application and am wondering if this is the best architecture to use and whether there is any danger.
In namespace Membership I have a public class, MembershipManager, which inherits from webservice
public class MembershipManager() : System.Web.Services.Webservice
The single public web method of this class often needs to read and write to a database.
[WebMethod()] public string DoMembershipWork(...various parameters...)
The database work is done by implementing, in the same namespace,an internal class
internal class MembershipDataAccess
which has a series of internal static methods for data access e.g.
internal static bool UpdateMembership(MembershipManager m)
The MembershipManager class accesses the data access class by calling the appropriate method with itself as a parameter e.g.
MembershipDataAccess.UpdateMembership(this);
Is this a good idea. This application will be processing many transactions simultaneously. Is there a danger of not being thread safe. Note also that sometimes the MembershipDataAccess class will return datasets to the MembershipManager class.
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Jun 28, 2010
I have searched deference between Static and Singleton Patten on google but did not get it clearly.
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Mar 30, 2010
See in below I have writtine a
1. Singleton class Emp1 with Display Method and
2. Static Class with Static Method Display.
What is the advantage of singleton class over Static Class with Static members?
[Code]....
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Aug 17, 2010
I have an app that I am testing with NUNit. The project im testing has several helper classes that are created as public static readonly. When I run the NUnit tests, they all fail with the same error
Systems.Code.Test.TransactionTest.CreateDataContext_ConnectionString_ReturnsDataContextObject:
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Nov 11, 2010
I have an ASP.NET HttpModule that is distributed as a DLL. I badly need a plugin architecture so I can isolate some heavyweight, rarely used features into external .dlls, and speed up/slim up the core functionality.I've experimented with (1) reflection and (2) static constructors.It seems GoDaddy and a few other web hosts prohibit use of Reflection, making #1 useless..NET 4.0 now calls static constructors lazily, eliminating #2.
How can I have a generic plugin registration system that doesn't require C# or VB code to register the plugins? Even a web.config plugin registration list would be fine, but I don't know how to do that without using reflection.
Update: I need this to work in .NET 2.0 as well as higher versions
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Mar 1, 2011
I have an asp.net application with c# language. I have a common class which maintain the constants and static variables and fields. I also have a login page. If the user logs in successful I set IsLoggedInSuccessfull as a static boolean variable in common class.
My question is: Will this only work for a specific user session or for overall application ?
Edited:
Based on some answers I got another question here.
let say i am using the Static method as Authenticate(User objUser). intention is to call this method when user clicked log in button. where on login button I am let say prepare the User object with certain parameters required for login, then passing to this method. what would be the impact there? let say I have single server for now (no server farm or garden). then there will be the single application level method to authenticate the user, right? and say 10000 user are going to logging in to this site/application then how authenticate() method comes in behaves ? will CLR automatically manage threading there ?
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Feb 4, 2011
I am developing a web application, which has Data Access Layer and this layer has only one class, in which all methods are static methods like static Insert, static Update, static Search. It has no properties. I am using these methods in my Bussiness Logic class for my users who are visiting my website.Now my question is : 1. Is it right to use static methods in this scenario ?2. What will happen if 10 users call Insert method at the same time ?
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Jan 5, 2010
let me know what does these access modifiers means.private shared vs public shared vs protected shared
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Jan 11, 2010
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?
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Aug 25, 2010
is there any impact of using static methods in Business Access layer in 3 tier applciation,
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