Asp.net - Calling Other Functions From A Shared (or Static) Function
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()> _
[Code]....
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.
View 1 Replies
ADVERTISEMENT
Dec 6, 2009
If I have two threads both calling a normal function at the same that appends strings, sometime the output string is a combination from both threads as the function had not finished executing the code before it was called again... Would a shared function wait to finish first?
View 9 Replies
Aug 9, 2011
I would like to understand the Pro & Cons in using the commonly used methods via Singleton class against Shared (Static) members of a class in VB.Net. It could be in terms Time, Space complexity or best practices. I have a BankAccount class with methods doing some business logic.
GetBalance()
GetLast5Credits()
GetMiniStatement()
[code].....
View 4 Replies
Aug 27, 2010
Is it possible to prohibit an instance of a class from calling a shared/static method?
For example:
I want to allow this:
ClassName.MethodOne()
But I want to disallow this:
Dim A As New ClassName
A.MethodOne()
The reason this is desirable is that in this case it is semantically confusing if an instance can call the method.
View 2 Replies
Dec 30, 2009
how I can dynamically load a control inside of a shared/static function?The function itself is inside of a mustinherit/abstract class.(It's an ASP.NET project in VB) I want to do something like this:[code]I'm getting "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.",but I don't understand this error.I understand what it means, I just don't understand why calling LoadControl isn't seen by the compiler as being an explicit instance of the class. What's not explicit about using LoadControl to create a new control from a file? I tried creating a new user control and initializing it, then setting it to a different control with LoadControl to no avail.I also don't want to do a DirectCast because I'm trying to put this in a shared, mustinheret (abstract) class, which therefore doesn't have an .aspx file to write in a <%@ Reference Control="~/SomeControlPath.ascx" %>, so the class name is unavailable.What I'm trying to do is write a static function that takes some value and returns a control based only on that control's source file location.The end result is a user-modifiable list of controls.They get a column of controls that they freely add, remove, or reorder based on a static list of available child controls that I specify.
View 4 Replies
Dec 6, 2010
What I am trying to do is have a class where the functions of the same name are both instance functions and shared functions.
Public Shared Function Get...(byval xx as xx)
and
Public Function Get...
The Public Function uses a Property xx created in the constructor, whereas the Shared Function has the parameters (byval xx as xx).
View 1 Replies
Mar 22, 2011
I have a midterm project where we must replicate what our teacher has made, it is a convenience store program. I am having trouble calling the functions, he wants us to use these:
PopulateItems => Populate Items listbox based on the category selected
GetItemPrice => Retrieve the price for a given item
GetItemPriceFromPurchases => Retrieve the item price from the purchases list box (optional. You may not need
[CODE]...
So far I have the first list box populated when the form loads. However outside of that I do not know where to call the function in order to populate the second list box upon selection of the first.
View 3 Replies
Aug 12, 2009
Given in the following language specification, for me at least, calling Db.Foobar() [In the following code] does not indeed call off to the Shared Constructors of the base classes. I am curious as to a) is this my own fault for doing something wrong or b) is this an error in the language specification[code]...
View 2 Replies
Jan 6, 2011
I have the following code:
Public Class TestClass
Public Sub Main()
If theGlobal IsNot Nothing Then Throw New Exception("What gives!")
End Sub
Private Shared theGlobal As Object = Nothing
[Code] .....
Why is theGlobal object NOT Nothing?
View 2 Replies
May 4, 2009
I've got a shared class (static in C#) which mostly carries some settings data that any class in the application can read and sometimes write. Also there are some static properties which holds some internal states.
Now I want to revert this class to initial stage of it. With all default variables etc. Assume that the user want to reset the current state and start over without restarting the application.
In a singleton model I'd simply renew it with something like this :
Public Sub Reset()
_Instance = New MyClass()
End Sub
However this is not possible in a Shared class. Or should I switch back to Singleton?
View 3 Replies
Oct 27, 2009
I Want to know which one is preferred while coding to use Static Methods or normal instances, I prefer to use static if they where few but if there was many of them I start to get some doubts
[code]...
if the EmployeeManager Has Many methods (selects deletes updates) is it ok to make them all static.and if it was Normal instance. wouldn't be a drawback if the object is initiated every time specially if GetAllEmployees() is heavily used.What is the better approach to use?
View 3 Replies
Jun 22, 2009
exact diff b/t Static v/s Shared variables in VB.NET?
View 3 Replies
Sep 27, 2009
I'm creating a Shared (static) method in ASP.NET MVC so it can be used by any controller in my project. This static method needs to generate a URL. I think I need to use System.Web.Mvc.UrlHelper, but I can't figure out how to call it from within a static method.The constructor seems to want a RequestContext.
View 1 Replies
May 25, 2010
[using VB.NET, but I can easily read C# code in responses]I have a class called QuestionClipboard with ALL shared methods/properties. I previously had a QuesitonClipboard.doesClipboardHaveContent function that returned true/false if there was a Object on my 'clipboard'.I'd prefer to implement a Dependency Property so I can allow this true/false value to participate in data binding.The "GetValue(dp as DependencyProperty)" method requires an object instance, which would mean that my Property CAN'T be shared!Here is what the code would look like in my perfect world... Of course, the word "Shared" before the property declaration renders this code useless.
Private Shared clipboardHasContentPropertyKey As DependencyPropertyKey = DependencyProperty.RegisterReadOnly("clipboardHasContent", GetType(Boolean), GetType(QuestionClipboard), _
[code]....
View 1 Replies
Mar 27, 2010
[code]Now how do i do this in c#. I know there is not handles clause in c# so i need some function that is called and assign the event handlers there. However since its a shared class there is no constructor i must put it somewhere outside of a function.
View 2 Replies
Dec 30, 2009
I have faced with a situation in VB.NET and C# (.NET2) with the visibility of the static/shared members. It seems to me a little strange in VB.NET:
public class A {
private static A instance;
public static A Instance {
get { return instance; }
} public string Name { get { } }}
[Code] .....
Shared member behaves like a class public one I can repeat it to infinite..
View 3 Replies
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? Is it even possible?
View 3 Replies
May 15, 2011
If I have a 'Shared' object defined in the App_Code folder; is that object shared amongst all users/visitors of my website? Or is it shared on a per-user basis?I don't know if that makes sense or not; but I've got a puzzle/solver I'd written earlier that I'm trying to incorporate into a simple ASP.Net site. It's probably poorly written, but I'd used a Shared boolean to determine if a solution had been found. The code works, now as an ASP.NET site, but if two visitors to my site were both validating their puzzle at the same time, would they both be accessing the same boolean?
View 3 Replies
Sep 7, 2011
I took over an ASP.NET application and have found this throughout several classes in the application. The programmers before defined several shared/static variables that act as "complex enums" throughout the application. As a fairly new programmer, it doesn't look like best practice.
Here is an example:
Public Shared SecureCommentsWrite As New Task("Secure Comments Write")
Public Shared SecureCommentsRead As New Task("Secure Comments Read")
Public Shared EditEmergencyContact As New Task("Edit Emergency Contact")
Public Shared DisplayPersonalReferences As New Task("Display Personal References")
Public Shared EditPersonalReferences As New Task("Edit Personal References")
The constructor takes the description, then loads the ID key from the database using a stored procedure (the database is SQL Server.) This seems like a good idea since we deploy this application to multiple databases and want to ensure that we load the ID key that's in that database in case it changes. However, since there are literally hundreds of these in the application, the first load takes a while.
View 4 Replies
Aug 18, 2011
Why there is only a static/shared version of ForEach for arrays?
IE: ForEach<T>(T array[], System.Action(Of T) action[])
I assume this has something to do with the type inference requirements of implementing an instance method, but when you declare your array you provide type right?
View 2 Replies
Apr 5, 2011
is there a difference in performance when making properties static/shared that were instance properties before, maybe any locking mechanisms?There is a heavily used object in HttpCache which was accessible through a property in a page-instance(Service.aspx). Now i wonder if it would be better to make it static because the HttpCache is shared across the application anyway.
View 4 Replies
Aug 4, 2010
I'm a newbie to threading, trying to learn it as I go. don't make any assumptions and try to explain threading concepts and rules that might seem obvious. I have a Module (Static class) as follows:
Module Main
Private ReadOnly _dbConn As SqlClient.SqlConnection
Public ReadOnly Property DBConn() As SqlClient.SqlConnection
Get
Debug.Print("Accessing DBConn")
[Code]...
All throughout the application, when i access DBConn on the same thread, it works as expected. howeve, later on I created a background worker that tries to access DBConn and nothing happens, the thread just hanges (the Background worker). I dont get the printout and the application doesnt continue. the background worker thread doesnt continue past that point, and so the thread never exits. I dont get any exceptions, and i Cant debug in Visual Studio (visual studio hangs).I guess its a 2 part question: why cant i access DBConn from the other thread, and why does it hang without giving me a threadAccess exception? also, why does visual studio hang (I'm assuming it hanges because the thread is hanging)?
Please Note: I am not asking about practice. I know I shouldnt be sharing the same connection, rather returning a new connection. in this particular application it is safe since (although i execute it on a background thread) as per the flow of the application, the connection can only be accessed one at a time. I just want to know why it hangs accross the thread.
View 1 Replies
Mar 3, 2011
Here's an example of what I'm talking about...
Public Class Sample1
Public Shared Function MyValue() As Integer
Return 0
End Function
Public Sub Code()
[Code]...
Me.MyValue gives a warning in VB.NET and (the equivalent code gives) an error in C#. Is there a particular reason for this? I find it more intuitive/natural to access the shared function using 'Me.MyValue' - but I avoid it to keep my warnings at 0. Did someone else just decide 'Nah, it makes more sense to do it the other way' or is there some technical reason I don't understand?
EDIT: I was thinking of it wrong, more like a 'sub class' in OOP. Even if something is declared in the base class, you access it through the instance you have. But that relationship is not the same with shared or static.
View 6 Replies
Apr 12, 2010
I would like to display static (shared) objects at runtime in a PropertyGrid but if I try to set the selected object property of the grid like this:
[Code]....
Is there a way to display a static (shared) object or the object's properties in the PropertyGrid?
View 1 Replies
Sep 13, 2011
I'm trying to host some static files for access by an ASP.Net web role and a separate data worker role that are both running on the same deployment (they use a global static interface).
However, I'm unsure how exactly to 'host' them, I've tried using virtual folders via HttpRuntime.AppDomainAppPath, but it only occasionally works in debug mode. The files also don't seem to get packaged into the deployment packages made by VS vis CSPack (though this might be a separate issue, is it possible to fix this too?)
The static files in question are actually WordNet, which I'm using through WordNet.Net, If that makes any difference. I also need the solution to work in both the cloud deployment and the emulator (if possible).
View 2 Replies
Mar 2, 2009
I have a class called PunchEvent. In the class I have an Enum called EventReason. I want to have a function Public Function ReasonToString(ByVal Reason As EventReason) As String. That is defined "near" the class (ie in the same file?) but is not actually part of the class (ie. it is not a member function). In c++ I guess this would be a static function? I tried to just define it after the "end class", but it says "statement is not in a valid namespace". Any recommendations?
View 5 Replies
Aug 23, 2011
Will the list in this shared method keep its state throughout the life of the method? Or will a new list be created every time this method is called?
[Code]...
View 3 Replies
Jun 6, 2009
I'm looking at a VB.NET class (that I didn't write) that is declared "MustInherit" (abstract in C#, I believe) that has three methods, all of which are defined as "shared" (static in C#). There are no properties or fields in the class - only the three methods. From an OO perspective, does this make any sense?
My thinking is no, because by making it MustInherit, you're essentially saying you can't create an instance of this class - you must inherit from it and create an instance of the derived class. But since all the methods are shared, you'll never actually create an instance of the parent class anyway, so the "MustInherit" does no good. You might as well not mark it MustInherit and just inherit from it whenever you want.
View 3 Replies
Jul 31, 2009
I am working with VB.Net and am kinda new. I was wondering, if my asp.net project has a lot of shared functions, can I put them all into one Namespace? Do I have to put them into a class?
View 7 Replies
May 21, 2009
I was wondering how to implement a vb script file with functions and subs that can be used in all code pages of a project. Similar to the old VB 6 bas files.
View 2 Replies
