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?
View 3 RepliesI'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,
I'm having trouble exposing a method to a silverlight client from a WCF service although I can expose properties.
My WCF service has a LoadDeal method which returns a Deal object
public Deal LoadDeal(int dealerId)
{
Deal d = new Deal();
d.LoadDeal(dealerId);
return d;
[Code]....
This works fine and the Refernce property can be accessed from the silverlight client.
But when I try to expose a method such as the CancelEdit method below, I can't find a way to expose this method to the silverlight client:
public void CancelEdit()
{
//Add logic to cancel changes here.
}
I've tried adding the DataMember annotation but the compiler complains. I've re-compiled without an annotation and then updated the service reference but nothing seems to be working.
I have a private static field in my Controller class in an MVC web application.
I have a static method in that controller that assigns some value to that static field, I want to apply lock on that static field until some other instance method in the controller uses the value stored in the static field and then releases it.
DETAILS:
I have a controller named BaseController having a static ClientId field as follows and two methods as follows:-
public static string ClientId = "";
static void OnClientConnected(string clientId, ref Dictionary<string, object> list)
{
list.Add("a", "b");
// I want the ClientId to be locked here, so that it can not be accessed by other requests coming to the server and wait for ClientId to be released:-
BaseController.clientId = clientId;
}
public ActionResult Handler()
{
if (something)
{
// use the static ClientId here
}
// Release the ClientId here, so it can now be used by other web requests coming to the server.
return View();
}
I'm totally new to the Microsoft dev scene so please go easy :)Currently, I have a solution that contains two projects (ASP.net websites, FWIW). If I create a class in Project1, how do I expose it to Project2? Is it automatically available to Project2 because they are in the same solution? Or do I need to do something special to make the connection?
View 5 RepliesI did some research after posting. All I found was simple examples for no-layer architectures, like connecting to a database from your aspx page, so, in a corporate environment, it is unnaceptable.
I need to call a server-side method (using ASP.NET Ajax) in a 3-layer architecture.
For example, my Default.aspx contains a method LoadProducts().
[Code]....
[Code]....
This cannot change. There is no way to convert Business and Data layers to static.
How can I call the LoadProducts() method using ASP.NET Ajax?
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?
Whenever I create a new folder in my website (VS008) and add an item (Class) it can't be seen by the other pages, even though new class is public. Only if I add the class to the app_code folder or create a bin folder for it then it could be shared from these folders however I want to create my own custom named folders for organization and keep my classes there.
View 2 RepliesVWD 2010 Express.
We have shared CSharp classes put into a shared folders for re-use. Now I want to add those classes into my project by creating a new folder:
1) Right click the solution,
Add -> New Folder
Give it a new, eg. SharedClasses
2) Right click the new folder "SharedClasses"
Add- > Existing Item...
Browse to the "Shared Folder", include those shared classes. But those files are added physically into the folder "SharedClasses" rather than a reference. How do I just add a link to those shared files? Since these files might be modified from time to time, I don't want to delete and add those file frequently.
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.
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?
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?
View 2 Repliesmy 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]
I am using DataClassesDataContext to map all the tables from the db into my asp.net application.For doing CRUD operations i have made static classes with methods, and inside every method a instantiate DataClassesDataContext.For instance:
public static class UserQ
{
public static User getUserById(int userId)
[code]...
Currently I have my data cached in Datasets in a static class. I was talking to my cousin's husband, who works as a C# developer for our local Telecom company.
Basically, I'm pretty new to ASP.NET and although to me having cached data in a static class makes sense to me, when I talked to him about it, he said there might be a problem when the site goes live, as on a web server more than one instance of the class may be created.
He did say this was a theory, and it was an area he didn't know an awful lot about, so I thought I'd ask some of you ASP.NET gurus to see if what I've done is totally wrong or not.
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?
View 5 RepliesI've read several other questions on this topic (here, here, and here), but have yet to see a great answer. I've developed my fair share of data access layers before and personally prefer to use instance classes instead of static classes. However, it is more of a personal preference (I like to test my business objects, and this approach makes mocking out the DAL easier). I have used static classes to access the database before, but I've always felt a little insecure in the appropriateness of such a design (especially in an ASP.NET environment).
Can anyone provide some good pros/cons with regards to these two approaches to developing data access classes with ADO.NET providers (no ORM), in an ASP.NET application in particular. Feel free to chime in if you have some more general static vs. instance class tips as well.
In particular, the issues I'm concerned about are:
Threading & concurrency
Scalability
Performance
Any other unknowns
I have a public shared function and I'm trying to access the values of a text box and a session variable.
I'm getting the 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."
Is there any way I can get to the values in the textboxes or session variables from within the method?
[code]....
The symbols won't load for a partial class (i.e. MyPage.aspx.cs code behind) and I need to debug that part of it. How do you get the symbols to load for a partial class and thus debug it while attached to process?Some other details: I publish my website (its an ASP.NET 2.0 site) which is with "Use Fixed naming and single page assemblies" checkbox which just creates a .dll for each aspx.cs code behind but no .pdb version of it. There are other ways to deploy like a single .dll file.
View 1 RepliesI have a serializable POCO called DataUnification.ClientData.ClientInfo in a .NET class library project A.It's used in a parameter for a web service defined in project B:
public XmlDocument CreateNewClient(ClientInfo ci, string system)
I now wish to call this web method from project C and use the original DataUnification.ClientData.ClientInfo type in the parameter. However due to the generated proxy class it has now become a different type: WebServices.ClientDataUnification.DataUnificationWebService.ClientInfo.As far as .NET is concerned these are not the same types.
I have an extension method as follows:
public static class PageExtensions
{
public static int GetUserId(this Page targetPage)
{
var user = Membership.GetUser(targetPage.User.Identity.Name);
return (int)user.ProviderUserKey;
}
}
Now in a page I need to use this method in a static WebMethod, so I have added another 'extension method' to PageExtensions:
public static int GetUserId()
{
return (int)Membership.GetUser(HttpContext.Current.User.Identity.Name).ProviderUserKey;
}
and I call it as follows in my WebMethod: PageExtensions.GetUserId()
let me know what does these access modifiers means.private shared vs public shared vs protected shared
View 5 RepliesI'm trying to implement a view tracking web service on my website. I'm using JavaScript because I want to exclude any search bots from my tracked views. The problem is I'm getting a "Unknown web method" error when I try to use jQuery to post to the web service I've created.
$(document).ready(function() {
$.ajax({
type: "POST", [code]...
The error is an ASP .NET error: Unknown web method TrackItemView. Parameter name: methodName.I've done this hundreds of times (seemingly), but I just can't see what I'm missing. I'm sure it's something small...
I have the following static function in c#
public static string Greet(string name)
{
string greeting = "welcome ";
// is it possible to pass this value to a label outside this static method?
string concat = string.Concat(greeting, name);
//error
Label1.text = concat;
//I want to return only the name
return name;
}
As you can see in the comments, I want to retain only the name as the return value, however I want to be able to take out the value of the concat variable to asign it to a label, but when i try the compiler refuses, can it be done? Is there a work around?
Can we declare a static method inside the Interface?If not means Why?
View 4 Replies