As I stated before in my Sorting questions.When is it advisable to use Shared Functions vs Instance Functions References.The problem I posed was that in a threaded application if I was sorting an array of 999999999 elements I typically want to call a shared function that handles this; however in .NET the way to sort is through a .Sort method which you pass an array to be sorted and a function handler; or Comparisson(t of).
My impression is that if in order to do a ClosestToN Sort I would have to calculate the value of N in the array first; then sort and then subtract the value of N from the sorted array.JohnH suggested passing the value of N as a Property in a Class that contained a reference to a sort Algorithm.The benchmark suggested in a 1 thread model it would work faster (which I knew that it would through math, but the accessors I was speculative on; I turned out to be wrong it worked fine either way).
My issue is in a Multi-Thread application creating instances for an accessor may cause memory to fill quickly if I am dealing with 1000's of threads.Is it better in this case to use a slower Shared function, then a faster Instance Function?
After I formatted my laptop and reinstalled Visual Studio 2005, I receive a lot of same error as below message. "Access of shared member through an instance; qualifying expression will not be evaluated" If I click the error, it direct me to the line and all 102 error suggest me to add "Windows.Forms." before "DialogResult.OK". Should I add something on "Reference"?
I would like to create a global instance of a User Class that can be referenced by all the forms in my MDI application.This object may be set during the login procedure by the Login form but the user attributes are to be available for other forms. For example, MyUser.ID will be required for meeting the audit requirements whenever data is changed.
I have been thrown in at the deep end with an existing VB.NET project at work. I have never used VB.NET before so I am struggling a little. Does anyone know how to solve the following.I need to pass an instance to client side and then pass it to a shared method in order to access instance methods from when the shared method.The starting point is a fileupload control within the HTML of my Contacts.aspx file:
The onchange event calls a javascript method, see below, this uses AJAX PageMethods to called a Shared method in my code behind This is the script code which is in my Contact.aspx file
[Code]...
If anyone knows the solution please could they update the code as I probably won't be able to understand if you just give a description. I just hope I am along the right tracks.
Suppose I have a class of objects called Porky with a property called IsHuge:
Public Class Porky Public Property IsHuge As Boolean End Class
Now I want to make a special kind of Porky -- let's call it UberPorky -- for which I want to change ALL instances to either IsHuge or not IsHuge. What I'd like to do is this:
Public Class UberPorky Inherits Porky Public Overrides Shared Property IsHuge As Boolean
[code]....
The trouble is, I can't do that. I'm not allowed to reference MyBase or Me in a Shared property.
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.
I want to extend the BitConverter class with an overload of ToString() that takes a parameter of type Char, representing a value delimiter.Why? By default, the ToString() call returns a string representation of a byte array, delimited by dash symbols. The signature does not allow you to specify a different delimiter, which I find very unfortunate.Now because this is not an instance type, or maybe because I'm overloading a shared method, I'm having a hard time finding the proper syntax to define my extension method.What am I doing wrong here, causing the overloads to not show up in IntelliSense:
What is the purpose of using shared methods that return an instance of a class, as opposed to a constructor?
ie: in VB.net, the system.drawing.color class has shared method "FromArgb(int, int, int) as color". This is different from java's implementation which simply is a constructor that takes three ints. Why the decision to do one or the other?
The context of this question is that I am trying to debug performance issues (apart from the obvious ones I already know about and can find).I inherited a code base (VB.NET) for an ASP.NET app. This is an app that was developed way back in .NET 1.1 days, and was the first .NET app for a lot of the developers who worked on it.
In this code base is a class called DatabaseUtility that contains several Shared Public methods as well as non-Shared Public Functions and Subs for CRUD operations to the database (SQL Server).
It is common in my "BL" that a method creates an instance of the DatabaseUtility which essentially figures out what the connection string should be and opens a connection, as well as giving the developer a handle to the other methods contained within it.Dim utility as New DatabaseUtility()
Once I have that, I start to create parameters that I am going to pass to one of the methods in DatabaseUtility (like GetDataSet). There is a Shared method in my DatabaseUtility called CreateParameter which does essentially that. It creates a SqlParameter object so I can add it to a Parameters collection.
Now, the code base is littered with a lot of this:
utility.CreateParameter(...)However, because CreateParameter is a Shared method, I am not sure what is going on behind the scenes. I know because it is a Shared member that an instance of the DatabaseUtility is not created when I call it like this:DatabaseUtility.CreateParameter(...)
However, because I am calling it from an instance (utility), does that change the behavior at all?
If I have a very large function/sub in a class that is an instance method (i.e., not Shared), do I gain or lose anything by moving that to a shared method and then declaring a small stub method for the instance use?
I.e., I go from this: Public Sub MyBigMethod(ByVal Foobar As String) If String.IsNullOrWhitespace(Foobar) Then Throw New ArgumentNullException("Foobar") End If [Code] .....
My thinking is I save on memory size per each instance of the object. Because each instance only has to lug around the stub method which handles calling the shared version and passing an instance of itself to the shared method so that it can do whatever it needs to do. But I'll wager that I sacrifice a very teensy amount of speed because of the added function call overhead.
I have Crystal Reports 2008 installed on my win7 laptop but when i go to insert references from my application settings the CrystalDecisions references are missing and im not able to find them. Note: they do exist in my "c:windowsassembly" folder.
I'm currently refactoring an old Visual Basic DLL (VB.Net), which stores all of its data in one module called Globaldefinitions as public fields. There are about 200 fields, referenced thousands of times all around the code:
Public Module Globaldefinitons Public a As Short ... Public zz10 As Double
[Code]...
I need to change the module into a class with non-shared fields. This means, each and every of these thousands of references needs to reference the instance of that class:
globalDefinitionsInstance.a = 5
How do I go about this efficiently?
Regular expressions operating on the source fall flat. Refactoring tools like Re-Sharper or CodeRush don't seem to offer this functionality. Visual Studio 2010 cannot do it automatically either.
I have an app the writes to the eventlog correctly in xp. The code does not work in win7.
CODE:
I get an error about inaccessable logs:security. I get that. Run as admin it goes away. I do not want to have to do that every time for every user that runs the app. besides they may not have the rights
So I wanted to make an instance of eventlog and set the Log to write to so it does not search the logs and error out on security.
CODE:
Now i get warnings about "Access of shared member, constant member, enum member or nested type through an instance; qualifying expression will not be evaluated."
How the hell else are you to set the log so that the code will work under win7 with normal user rights AND not get this silly warnings?
I have 71 places that I write to the eventlog. that may or may not be too many but that is for another thread.
i changed a class variable to shared so i can access it in all instances of the class, but it caused an error. what is causing this, and how can i fix it?
In the following code i get a warning at line 59:Warning 1: Access of shared member, constant member, enum member or nested type through an instance; qualifying expression will not be evaluated.and.. At line 78 I get this Warning:
Warning 2 Property 'SelectedCustomer' doesn't return a value on all code paths. A null reference exception could occur at run time when the result is used.
The program compiles and runs well, but i cant' undesrtand the reason for these warnings. Any Idea ?
1: Public Class Form1 2: 3: 'Form level members 4: Private objCustomers As New ArrayList
It works, when I make getBar methods public, but I don't want to expose these unneccessarily. Why I can't call private shared methods from a public one in the same class is over my head. I'm using .net framework 4.0 in a web application.
I've taken over the maintenance of the website (ASP.NET VB) and on one particular page I noticed the below code
Inherits System.Web.UI.Page Public Shared UserNumber As String Private Sub Page_Init(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Init
[Code]....
My question is whether the variable UserNumber can be accessed or changed by any other user than the current one?
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]...
I 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.
I 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...
I have following instance of System.Collections.Specialized.NameValueCollection:
Dim UserSelection As New System.Collections.Specialized.NameValueCollection UserSelection.Add("D_Color1", "Black") UserSelection.Add("D_Color2", "Green") UserSelection.Add("D_Color3", "Purple")
I need to save this instance to hard disk and then load it back from hard disk as an instance. How do I do that?
D is a dictionary whose entry values are of Type T..What I'm attempting to do is have a delegate like "Serializer" below that I can invoke on an instance of T, such as "Entry.Value" below.Please see the "return Entry..." line below for my wishful thinking.[code]
I am looking for a way to make my app running in a single instance mode and showing the MainWindow of the first instance when another instance is launched.I do a quick search on the internet but I did'nt find anything to open the MainWindow of the first instance or it was for Windows Form not for WPF.
I have a single instance VB 2010 application I know how to communicate with the next instances run through the StartupNextInstance application event. The usual way of working with this is parsing command line arguments of the new instance and continue execution of the old instance. What I would like to do is replace the running instance with the new one. Is there any way to do this other than disabling the single instance property ?
A while ago, I wrote a web-based guestbook application that wrote it's own database.
My code was very amateurish, but, as it was my very first publication, I was very happy with it. Only about a month after I'd published it did I realize I'd made a huge mistake in the code.
I've only ever connected to a specific named instance of SQL Server, and it occurred to me that, if the SQL Server instance has a different name than the one I specified, it wouldn't work.
So, since my users will probably not know what the name of the instance of SQL Server that's running is, I thought adding a field where the user can specify it would help if they do, but what if they don't? My answer was to get the local instance, regardless of name.
I tried Data Source=.local;, Data Source=.; and other variants, but nothing worked.
I was trying to fill 10 checkedlistboxes with items..So I made a sub with 2 arguments like this Private Sub fill_checkedlistboxes(ByVal items As String, ByVal checkedlistbox As CheckedListBox) End sub the first argument items is a long string whitch splits in the sub into many strings and added them all into the second arguments (thecheckedlistbox) I want to make for next statement to fill all the 10 checkedlistboxes in my form with an 10 long strings held in an array called strings, so i write something like this [code] What i have to write in the "?????" area to have the checkedlistbox that i want? the checkedlistboxes names are checkedlistbox 1, 2 , 3 ....10
