Why Doesn't XmlSerializer Work For Shared Class Variables
Dec 8, 2011I have the following class which I want to serialize to XML:
[Code]...
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Use Derived Class Shared Variables In Shared Methods Of Base Class?
Jun 4, 2010I am trying to add shared members in derived classes and use that values in base classes...
I have base
class DBLayer
public shared function GetDetail(byval UIN as integer)
dim StrSql = string.format("select * from {0} where uin = {1}", tablename, uin)
end function
end class
[Code]..
currently there is error using the tablename variable of derived class in base class but i want to use it i dun know other techniques if other solutions are better then u can post it or u can say how can i make it work? confused...
Local Variables In Shared Method Work Like Static Variable In C?
Aug 23, 2011Will 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?
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Access Shared Variables Of A Class?
Jul 23, 2009I am making a small application in which i have added a class module and a window forms in vb.net. i want to acess the shared variables and mathods of class without making any object.
View 8 RepliesVS 2008 - Class Doesn't Work
Aug 1, 2009When I use this
[code]...
But for some reason, it doesn't place the image into the picture box.If I use this, and replace it with the first box of code, then it works fine.
[code]...
So, why doesn't it work in my class?
Converting Object To Class Doesn't Work
Jan 9, 2011I am using VB.NET 2010.I have a Queue to save different data (which all come from a class of mine) as FIFO Now, I want a Function to count the saved classes in my Queue, but this isn't working
My Code look like this
Private
Function
QueueSum(ByVal
myQueue As
[code]....
TryCast seems to be wrong. - because the Intelli Sense tells me, that "SATZ" isn't declared.
Asynchronus Output Capture (BeginOutputReadline) Method Doesn't Work From Separate Class In VB
Jun 11, 2012I've got a simple tool written in VB in VS 2010 that has a series of command buttons which run Windows command files and the output is sent to a Rich textbox object on the main form (the comand files take awhile to run so I wanted the output to show up in the RTB as it was produced to show progress). All worked well until I made an update to the tool so that the series of buttons are no longer hard-coded, but created dynamically from information in the app.config file. To do this, I use a button
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XmlSerializer To Serialze A Class With A Collection?
May 26, 2010I have a custom class that has one property as a collection.For some reason XmlSerializer doesnt like the class having a collection property and the Serialize Fails!If I remove the collection property it works! Is there a special way of getting the collection in the class to work?
View 1 RepliesPut The XMLSerializer Behind A 'facade' Class That User Won't Have To Supply Type Info To The Constructor?
Mar 19, 2012I wish to put the XMLSerializer behind a 'facade' class of mine so that user wont have to supply type info to the constructor. But doing this has a problem. Consider this class:
Class XmlFormatter
Private Shared xs As XmlSerializer
Public Function Deserialize(ByVal serializationStream As Stream) As Object
Dim o As Object = Nothing
[code]....
The problem is that the user of this class cannot use Deserialize without first using Serialize because the XMLSerializer instance is created in Serialize and it is shared. But using Deserialize without this instance will simply return Nothing.
Why Doesn't The DeleteDirectory Method Of The Computer.FileSystem Class Work On "special" Folders
Aug 14, 2008if they choose to use a networked version of my software, I will need the main server doing the authenticating. This is a problem, because from what I understand, it is quite easy to clone MAC addresses. I have looked into using the CPU ID and the HDD ID, but those are not unique, well at least I don't think so. Reason why I say they are not unique is because someone has the exact same CPU ID as me, and the HDD ID changes from partition to partition (same drive). Maybe the HDD ID is a partition ID instead? Anyways, I was thinking maybe I could get the Physical serial number of both the HDD and CPU, but I have not been able to find anything yet.
View 2 RepliesWhy Doesn't The DeleteDirectory Method Of The My.Computer.FileSystem Class Work On "special" Folders
Feb 18, 2010We have a network share that is used for transferring files between users on a daily basis. Every day at 3:00 am we run a vb6 program to clear the directory of this network share.
View 1 RepliesTooltip On Windows 7 Doesn't Work VB2010 - Thecolor Doesn't Change ?
Jun 12, 2011I am trying to change the background color of a tooltip
I am using tooltip.backgroundcolor = color.colr
No errors but thecolor doesn't change
PerformClick() Doesn't Work - How To Make It Work
Feb 2, 2011I have an application that requires data be entered, and after entering, a button is clicked to process that data. Clicking the button works just as it should--the data is processed properly. In constructing a test module, I provide a set of data values, followed by:
btnWhatever.PerformClick()
Nothing happens. I have used this syntax for years, and it has always worked flawlessly. I have triple checked everything else and isolated the problem to the failure of the PerformClick(). The PerformClick() is in a test subroutine that does nothing but fill textboxes and labels with default data, then calls the PerformClick() on the button to begin processing. Again, the button works fine, the data is entered as it should be, but the PerformClick() does not fire the click event.
.net - Shared Variables Among Subclasses?
Jan 18, 2011I have a problem with inherited classes. Have a look at the following VB.NET 2.0 / VS 2005 code:
MustInherit Class templateclass
Public Shared x As String
End Class
Class child1
[code]....
The templateclass has a shared variable x which is of course inherited by the child classes. But I wonder that all child classes share only one x! Until now I thought that shared variables are only shared among the instances of a class, not among all childs. This is very annoying because I have a base class which I need in two slightly different versions and they should not "share the shared" variables. And because the classes have a lot of shared variables, shadowing each in the childs would be very..
Shared Variables And DLL Usage
Oct 20, 2011I'm trying to split some prior crafted code into a DLL. It's a simple logger system.There are a few things that need to be shared with the main form in the project, so I set them up as a shared variable, but I don't use shared stuff often, and I worry it will cause variable conflicts regarding scope. I figured I would make a post here about it and see if someone can explain what I don't fully understand.Since this is a logger it will be used a couple of places. Other DLLs that need logging may reference it through a instanced object and project reference. My main form will also have an instanced object and a reference to the logger libary.Since one of my properties is a connection string and it's shared, does this mean that a instance of my logger class inside a DLL will have the same shared values as a instance on my main UI form? Or will the fact that the instance is inside of a DLL provide the scope boundary I need?
View 1 RepliesDefine Some Global Variables Of A Class - Variables Occupy Memory?
Mar 23, 2012I define some global variables of a class as follows:
Private Class MyClass
Private var1 as Decimal
Private list1 as List(Of string)[code].....
But I found that after this form is closed, all above variables, var1, list1, list2 still exist in memory. I thought they should be collected by gc since the form is already disposed as I confirmed.
Add: I have monitored half an hour after the form is closed. But these variables are not collected by gc. I have an automatic update procedure on the form which uses above variables.Since the above variables still hold values, the automatic update procedure is always called which causes exception. (One quick fix is to check if form.isDisposed in update procedure. But I do not think this is elegeant. Besides, these variables occupy memory.)
Create A "shared" Variable That Is Shared With All Instances Of A Class?
Jan 14, 2011I seem to be drawing a blank. I'd like to create a "shared" variable that is shared with all instances of a class but not classes that inherit from it. For example.Class A: Shared list As New List(Of String): list.Add("A")
Class B Inherits A: list.Add("B")Class C Inherits B: list.Add("C")The end result I'd like is that any instance of A has just A in the list. Any instance of B has A and B in the list. Any instance of C has A, B, and C in the list. I can accomplish it by creating Instance variables, but I have to construct the list for each instance of a class. I'd like to construct it once for a specific point in the Hierarchy and then share it accross other instances of that class.
Local Variables Are Automatically Shared
Mar 13, 2012I was reviewing the MSDN documentation on VB.Net's little-used Static keyword for local variables. My question is not about how Static works (I personally plan to avoid using it as it seems like it could cause grief to future programmers who don't notice the side-effects.) My question is about this statement in the docs:[code]So can anyone interpret the above statement for me in a way that makes sense? Or is this a bug in the documentation? It's been there since the VS 2005 version of the docs and is still present in the Visual Studio 11 version.
View 2 RepliesDifference Between Static And Shared Variables In .NET?
Jun 22, 2009exact diff b/t Static v/s Shared variables in VB.NET?
View 3 RepliesInheriting Shared Variables/properties?
Nov 29, 2009basically i was wondering if we could inherit shared variables but restrict its scope to only that of the class itself.
Class A
Public Shared shared_variable as Boolean = true
End Class
[code]....
when i do this A.shared_variable = False, B's shared_variable also becomes false. how do i stop this?i cannot remove the Shared keyword because shared_variable should be able to be accessed without an instance of the class?
Shared Variables And Garbage Collection?
Feb 21, 2012I've been doing some reading on garbage collection in .NET and I was hoping for some clarification. So, as I understand it if I declare a public shared class variable, the GC will never get rid of it. Is this correct?Also, what then of private variables? Take the following example:
public class myClass
private shared myString As String
public sub ChangeString(newString As String)
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VS 2010 Shared Variables And Threading Pin?
Mar 12, 2012So I am currently attempting to wrap my head around create multi-threaded programs and I am currently running into an issue when using a Shared variable across multiple threads.The program is structured as follows: Public Shared IsActive as Boolean
Main Thread = GUISets the Value of IsActive through a Button ControlTwo Worker ThreadsBoth threads are while loops that read the IsActive Boolean Ex:While IsActive = True Do Work End WhileHowever when I change the value of IsActive from the Main Thread it causes the worker threads to stop (ThreadState = 16).
I have been reading that I have to synchronize/lock shared resources and have tried SyncLock and Monitor methods without success (it is entirely possible I am not using the above correctly, so If someone could provide proper examples for the above situation using the mentioned methods please share them).
Can't Inherit Shared Properties From A Base Class In A Child Class?
Dec 29, 2010This is another one of my "I think it's not possible but I need confirmation" questions.I have a base class for a bunch of child classes. Right now, this base class has a few common properties the children use, like Name. The base is an abstract class (MustInherit)Technically, this means that everytime a child class is instantiated, it lugs around, in memory, its own copy of Name. The thing is, Name is going to be a fixed value for all instances of a given child. I.e., Child1.Name will return "child_object1", and Child2.Name will return "child_object2".
View 1 RepliesUse Variables Or Properties, And Global Or Static Variables In A Class?
Jun 9, 2012I'm new in .NET programming.I have a class Form1 that includes Button1_Click event.Button1_Click creates a multiple Text Boxies at run time)Here is the class:
Public Class Form1
Dim shiftDown As Integer
Dim counter As Integer
[code].....
Accessing Variables From A Public Shared Subroutine?
Feb 15, 2009I have created a public shared subroutine in a class file in asp.net 2 (vb.net) web site app_folder.The subroutine retrives some values from a sql database via an sql query and assigns the datareader field values to several variables The problem is I can't seem to assign the variables from the subroutine to the variables and textbox controls in the asp.net page I am calling the subroutine from. The textbox text value just appear blank.By the way, if I response.write the variables in the subroutine they appear populated by the sql data reader.
View 9 RepliesLifespan And Scope Of Shared Variables And Functions?
Jul 31, 2010Are the following three the same upon compilation
dim x as new assigningfunction
dim x as new assigningfunction()
dim x as assigningfunction = new assigningfunction()
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Multithreading - Passing Variables In Shared Subs?
Apr 23, 2012Public Shared _formRef As frmMain
Public Shared f As frmMain
Class Server[code].....
but once firing off the code i get the error you see in my image attached.
Arguments / Parameters And Variables Inside Shared Functions
May 19, 2011Well I am a new to VB.NET, converting a legacy system to .NET world. Recently I have been reviewing the already existing code since I joined the project quite late in the team. I find that there are many shared functions (not shared class) inside many classes. I doubt this may create some problem if two requests ( i.e two different HTTP request to the same method as it's a WCF application, of course exposed methods are not shared but internally called methods are shared) comes to the same shared method and both the calls to the method may have different method parameters/arguments, overwriting each other's arguments. In short, if shared method has a list of arguments which is going to be processed, is there any chance of inconsistencies in the light of multiple access to the shared method via two http requests.
View 2 RepliesDifference Between A Private, Public, Shared Functions/Sub/Variables?
Jul 22, 2009give me a good resource that explains the difference between a Private, Public, Shared Functions/Sub/Variables? I normally use Public for Subs/Functions inside of Modules I call from other parts of the program. But I'd like to get more of an understanding of how and when to use them. I want as little as impact to a system that is running my programs as possible, so i guess the key here is I'm trying to just get more proficient in my coding.
View 8 RepliesPrivate Shared Variables Vs Local / Namespace Performance
Jun 8, 2009I came across a number of new Private Shared variables (of type Hashtables(Of String), initialized in the declaration) added to a partial class for a very large (DataContext-derived) class. This seems sensible to me in one sense because they never change, and making these shared variables ensures that they won't get re-initialized every time a function is called. However, these variables are only used within the scope of one function in the class, and I fear the private namespace of this DataContext-derived class is getting rather polluted, and having these sorts of things exposed at such a high level might be confusing to others reading the code in the future.
Would there be negative performance impact to making these local variables within the function where they are used, or is there some better way to handle this? Basically we are using these 3 hashtables to determine whether anything within particular subsets of properties changed (using GetModifiedMembers and then using the Overlaps function of the hashset to see if any of the modified members correspond to members we care about).
Edit: I caved and took the time to write my own test program, which confirmed that there is a cost to using local variables (which I assume applies generally to all cases -- I doubt there's any case where a shared variable would be slower unless using the shared variable requires some additional logic to do so properly): [Code]
So in this particular case, using the local variable costs about 200%. But in most cases (including my own), the time is probably negligible compared to the overall task. So I guess the question now becomes, how do people generally feel about improving code maintainability at the cost of negligible but known performance impacts?
