C# - Accessing Constructor Parameter ByRef?
Nov 22, 2010
I want to make a generic EventArgs sub class that has a write-only property which, when updated by the code that is handling the event, will also update the byref parameter of the constructor of the class.
The code I have so far doesn't work. How do I get the property "Item" to update the "item" constructor parameter so I can retrieve the value that was set?
public class EventArgsSet<T> : EventArgs
{
public EventArgsSet(ref T item)
{
[Code].....
View 2 Replies
ADVERTISEMENT
Mar 19, 2009
I have a legacy COM-component with an interface declaring a property like this (IDL notation):
[Code]...
This interface is implemented in a calling application written in VB6 like this:
[Code]...
Everyting works fine until I try to do the same in VB.Net. VB.Net refuses to compile code where a parameter of a property is passed ByRef. MSDN says VB.Net doesn't allow such parameters. Is there any way I could implement such a property in VB.Net?
View 3 Replies
Mar 19, 2012
I did create a XDateTime class that is able to handle inaccurate date and time. This class has all the CType operators required to convert to and from a string and it has been fully tested during the last months.
[Code]...
View 1 Replies
Aug 18, 2009
I have some classes, BsfciFile and StudyFlashCard. Bsfci is the extension to which I save my set of flashcards in an INI format. I am currently working to transform my code from using Windows API calls to access the INI to using a IniFile class that I found on the internet. I would like the BsfciFile to have a Array of StudyFlashCard objects, but I would like the StudyFlashCard class to use the IniFile class object contained in the BsfciFile class. I can pass the IniFile from the BsfciFile class to the constructor for the StudyFlashCard class, but I want it to modify the same IniFile as the BsfciFile class has later on.
[Code]...
View 1 Replies
Feb 12, 2011
I'm using SharpZipLib to compress files. The library is wrapped in a plugin interface, in a separate DLL. I pass the plugin dll a ByRef parameter to keep track of the compression progress.SharpZipLib, while compressing, will periodically call a delegate sub passed when launching the compression. I can't figure out how to update the ByRef parameter when the delegate is called. If I try to assign the ByRef variable in the body of a lamba expression, I get a 'ByRef' parameter '<parametername>' cannot be used in a lambda expression error.
[code]...
View 1 Replies
Aug 29, 2011
How can I get the name of the object that was passed byref into a method?
Example:
Dim myobject as object
sub mymethod(byref o as object)
debug.print(o.[RealName!!!!])
end sub
[code]....
I'm using this for logging. I use one method multiple times and it would be nice to log the name of the variable that I passed to it. Since I'm passing it byref, I should be able to get this name, right?This would give you the parameter name in the method and it's type, but not the name of the variable that was passed byref.
using system.reflection
Dim mb As MethodBase = MethodInfo.GetCurrentMethod()
For Each pi As ParameterInfo In mb.GetParameters()
[code]....
If you put that in "mymethod" above you'd get "o" and "Object".
View 3 Replies
Sep 4, 2010
I have a class OrderManager, that takes a parameter of type LocalFuturesList on construction. Now.. It doesn't seem to matter if I use ByRef or ByVal here.. It still references the parent class instance of it. It also doesn't seem to matter if I type New or omit it.. Probably also because it's just an address reference. But why is it like this? And what type of objects "acts" in this way? Further I find that if I change the object in the parent class by deserializing from a file (with my method call shown), then suddenly this reference is broken in some way, so the OrderManager instance now holds Nothing I believe.If my observations are correct I see two challenges:
1. How to pass a list NOT by reference?
2. How to maintain a list reference through deserialization? [code]
View 17 Replies
Feb 17, 2009
Is there a robust way to get a constructor with string parameter by reflection?I have no choice, but instantiate a class without knowing if the constructor belongs to it, a base class, or come intermediate class in the inheritance chain.
View 1 Replies
Oct 30, 2011
I'm trying to change the reference of a variable passed from one form to another in the constructor of the recieveing form but after I've changed it the original reference still remains in the source form. Why is this and can I force it to accept the new reference?
View 12 Replies
Sep 21, 2011
accessing values using ODS. i have no idea how to make this work.
im using ASP.NET VB code.
Imports Microsoft.VisualBasic.FileIO
Imports IP2V2.DataAccess
Public Class LotIDParameterDAL
[Code]....
View 4 Replies
Jan 12, 2011
I'm using an interop dll in a VB.NET project to get access to some functions in a MFC project.
Dim bIsSupposedToWork As Boolean = True
Dim api As API = GetObject(, "MyProject.API")
[CODE]...
Why?
View 1 Replies
Feb 15, 2010
I have an abstract class which requires a delegate to function. I pass the delegate into the constructor. Now that I have a non default constructor I need to call the abstract class's constructors from the concrete class which means that I need to use MyBase.New(...). I have included a quick example below.
Public MustInherit Class BaseClass
Public Delegate Sub WorkMethod()
Private _Work As WorkMethod
[code]....
I have tried to do this but I keep getting the following error: "Implicit reference to object under construction is not valid when calling another constructor".Can I not do what I am trying to do above? I initially had the delegate setup in its own setter method. But then I am creating a deceptive API because it does require a point to a method to work properly.
View 3 Replies
Nov 2, 2009
what's the rationale behind this limitation: Constructor call is valid only as the first statement in an instance constructor i want to pass an argument to my constructor which validates this argument and calls mybase.new according to this argument but it doesn't let me
example:
Public Class prob
Inherits System.ApplicationException
Public Sub New(ByVal problem As String, ByRef inner_exception As Exception)
[code]....
View 16 Replies
Sep 7, 2009
Below I tried to do an Example:
[Code]...
Below is the called method: Friend Sub SplitOU2(ByVal inDN As String, ByRef OUDN As Object, ByRef Organisation As Object, ByRef VerksamhetTyp As Object) By doing this I can skip to declare the in this example "useless" variable Dim VerksamhetTyp as Object = "".
View 3 Replies
Apr 21, 2011
Following code doesnt work and raise error "A parameter is missing. [ Parameter ordinal = 1 ]".What s wrong with it?I am developing pocket pc application in vs 2008 and sqlce 3.5 sp1.
[code]....
View 1 Replies
Mar 21, 2009
I'm Trying to Call the Stored Procedure which has one input Parameter and one output parameter . VB.net code is below
[Code].....
View 2 Replies
Mar 9, 2011
I want to have a "template" function that can receive different parameter and a type parameter, like:[code]But Vb told me that tupeList is not defined... is there a way I can do that?
View 2 Replies
Oct 26, 2011
Is it possible to make a procedure have a single parameter but the values for that parameter are more than one? I have this procedure:
Public Sub autoComplete(ByVal cboCombo As ComboBox)
With cboCombo
.AutoCompleteMode = AutoCompleteMode.Append[code]....
Now I was wondering if there is a way to use it like this:
autoComplete(myCombobox1, myCombobox2, myCombobox3)
Or can I use a procedure like this with 'With...End With'?
View 1 Replies
Mar 1, 2009
I have a method which requires a parameter to be passed in. I would like to use the Addhandler to call the method through a dynamically created button control's click event.
When I include () in the AddressOf, VS complains: 'AddressOf' operand must be the name of a method (without parentheses).
When I exclude the brackets, VS complains: Method '...' does not have a signature compatible with delegate...
My code:
CODE:
View 5 Replies
Dec 10, 2008
One of the things that I think is really cool about VB.NET is how built-in functions and subs have extra help text in their ToolTips like "Expression: String expression to search for replace string." as well as the usual "Replace(...parameters...) as string" text. So are the pop up boxes with things like "CompareMethod.Binary" or "CompareMethod.Text." And finally I like how some functions and subs have different sets of parameters for the same routine. For example, New FileStream() starts with either a path (string) parameter or handle parameter, but none of the 15 sets of parameters contain both path and handle parameters. Is there a way that I can set up the classes and functions I write to use these things or do they only work with built in classes and functions? If there is a way, what are the proper names for them so I can look them up in the VS/VB documentation? I would be happy enough if someone would give me an example of them, but it would be nicer if I could go through the documentation and find out if there are other cool things that are related or near by.
View 3 Replies
Nov 17, 2011
I am a student and i get confused when i see a lot of ByRef and ByVal arguments in a sub procedure. Can someone make it simple for me to understand when it should be used?
View 9 Replies
Dec 8, 2010
I've read a lot on this, but am having a hard time thinking through this tonight. (Maybe it's the hydrocodone... just had a root canal. i'm just starting on a class to handle client connections to a TCP server. Here is the code I've written thus far:
[Code]...
Now, on my Socket property, when setting the value, it is required to be ByVal. It is my understanding that the instance in memory is copied, and this new instance is passed to value, and my code sets _Socket to reference this instance in memory. Yes?
If this is true, then I can't see why I would want to use properties for anything but native types. I'd imagine there can be quite a performance hit if copying class instances with lots of members. Also, for this code in particular, I'd imagine a copied socket instance wouldn't really work, but I haven't tested it yet.
View 3 Replies
Apr 29, 2009
I have to work with an API that uses a lot of by-reference parameters. I'm just beginning to use NMock, and I'm having trouble seeing how to make NMock actually modify one of those by-ref parameters to a specific value. Am I missing something, or does it just not do that? Is there a better way, short of wrapping this API?
View 1 Replies
Dec 15, 2011
In VB.Net, I have an object named WorkflowButtonEventArgs that inherits from System.EventArgs.The WorkflowButtonEventArgs class contains two ByRef Properties. These are objects that are in memory, and I do not want them duplicated or copied in any way.
Can I pass the WorkflowButtonEventArgs object ByVal in VB.Net and have it still preserve the two ByRef definitions in WorkflowButtonEventArgs?Specifically, if I pass it ByVal:
Dim e As New WorkflowButtonEventArgs e has some ByRef properties RaiseEvent SomeEventName(e) ' e is passed ByVal Will the ByRef Properties/Members in e (WorkflowButtonEventArgs class) not be copied or duplicated in memory?
Long-story-short: Can I pass e ByVal, or do I need to pass it ByRef since it contains ByRef Properties?
View 3 Replies
Oct 20, 2011
The one calls form 2 as a dialog, and passed by ref a "pointer" to the base class(abstract).[code]...
View 2 Replies
May 4, 2010
[Code] What is the difference between ByRef and Byval in this function. When i call this function and debug it it shows no difference the two. Can any one explain me actually what happens.
View 8 Replies
Feb 20, 2009
ByRef (a.k.a. By Reference) points to where the object is in the memory. Any changes made to the object sent ByRef should change the values of the original object ByVal (a.k.a. By Value) points to a copy of the object. Any changes made to the object shouldn't change anything in the original object
Let's make an example:
Private Sub FormLoad()
Dim a As String = "A"
Dim b As String = "B"
[code]...
The second messagebox shows Baaaa - Buuuu instead of the expected A - Buuuu... but why is that? Apparently ByVal and ByRef does exactly the same thing. It seems like it sends the reference to the object when using ByVal, instead of making a new object.
View 2 Replies
Mar 27, 2012
Whenever I'm going to use a new API, I have to decide for each value whether I'm going to use byval or byref. Can someone explain me in what scenarios I should use which and why? Because lacking this knowledge kinda gives me the feeling of having no control over my code.I am aware about the other threads by people asking the same question, I have read them but its still not crystal clear for me.
View 2 Replies
Jun 5, 2012
I have seen a few people in the past confused on the usage of ByRef & ByVal in a Function/Sub's Signature. I figured i would make a simple example that demonstrates the difference of each.
Option Strict On
Public Class Form1
Dim A As Integer = 100
[code]....
If you want something you've never had, you need to do something you've never done. If you believe something to be true, then one day you will be called upon to demonstrate that truth.
View 10 Replies
Feb 9, 2012
I just installed Visual Studio 2010 Service pack (proposed on Windows Update), and I can see a new feature on the "intellisense" that means when I write a Function or Sub in VB.NET it doesn't auto-complete parameters with ByRef or ByVal...
1) Is there anyway that I can configure this option back to how it was before?
2) If I don't specify ByX, which one is used by default? (it seems like it is always ByRef)
View 2 Replies
