Advantages/Disadvantages Of Public Shared Functions
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).
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.
I would like to know if the forieng key should be nullable or not. We shuld struggle for not making it nullable as much as possible or it doenst matter.
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?
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.
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?
I have the following code in a class in which I call from different pages, I wanted to know where this info is being stored at as I can see it from different pages.
[Code]....
Also, is this saved on the browser session? IIS? will whatever being set from 1 user be affected by every other user on the site?
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?
I am using the following code for slide show of AjaxToolkit. It works. But I wanna get the label1.text as picture name But I cannot do it in public shared function ! How can I do that !
I have a gridview that is dynamically created and have finished all but one problem - I need for my code that is within a Public Shared Function to access a textbox string - In the below I need myinput to return the string so that my query's can use the variable - the below shows: 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.
If I remove the "Shared" the error goes away however it crashes other parts. (if I hard code the text then all works as expected)
I have a question about C Sharp ASP.NET:Is there a difference (in code speed, resources) between:public static variable declared in public static class MyGlobals in a 'Code File' template;and the variable declared in a normal 'Class File' template;I use this variable in 2 different Class Files and also in _Default Page codebehind cs file.In fact in my case I need about 20 global variables of type List<string>.
what is the disadvantages of using SqlDataSource Control? apart from flexibility and more control on the retrieved data ;why most of the web developer prefer using code behind (db connection) instead of SqlDataSource Control?
I have opened a large web project on elance for a social network. I got over 30 bids on my project and many of the providers recommended php even though they had .net knowledge. many have said that php with drupal has many advanteges over the .NET framework but did not say what they were. Its hard to believe that a scripting language has advantages over a compiled language.
