In vb.net the methods have their parameters using ByVal by default, it's better practice / common practice to make it explicit?
For example:
With ByVal:
Private Sub MySub(ByVal Q As String)
{
}
End Sub
I want to know what are classes , objects , a namespace , subroutines,functions,methods,properties and differemce betweem byval and byref in your words.
View 18 RepliesCode in VB.NET
[Code]...
works very well. So seems some consistency miss of the string constant behavior.
2) Have a look on the COMMENTS (in the attached picture). The words "custom", "string" and "error" are highlighted, however they are in the comments, so should be green, not blue.
Why this? What workaround? EDIT: Declared as "bug" in Microsoft Connect (even if is not more that a syntactic "miss")... EDIT 2: As remarked Hans Passant, standard string methods, like "cucu".Trim() does not work either.
<script runat ="server" >
Dim objDT As New System.Data.DataTable
Dim objDR As System.Data.DataRow
[code]......
Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
Textbox1 how the text box by real-time data monitoring?
I'm making this program that opens the same forder in every pc but it identifies the pc name to do it.
Public Class cv7import Private Sub cv7import_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
[Code]...
but I want it to do it with the pc's name and I'm not sure how the environment.systemdirectory works, or even if it's the right one to use. Is it the right thing to use or is there a better solution.
Just as a secondary question, usually I reduce: -(ByVal sender As System.Object, ByVal e As System.EventArgs) to just () for most occurrences of auto-generated subroutines. Is there any harm in doing this? I cant see any reduction in performance but do get more readability.
View 8 RepliesThis is the original code in c#
public class CategoryRepository: RepositoryBase<Category>, ICategoryRepository
{
public CategoryRepository(IDatabaseFactory databaseFactory)
: base(databaseFactory)
[Code]...
Does anyone has an idea what i should change to let it work and let my UserRepository use the methods in RepositoryBase while implementing the IUserRepository?
I am working with a vb program, but there is something strange on one of my .vb code pagewhen i put the "dot" afther the object name its dont show the methods availables for this objectbut on other vb code pages i can see it. but in this one no.for exmaplethis is a piece of code: Dim sb As New StringBuilder()
View 3 RepliesI am not sure how clear my question is by the title, but I am trying to make Class methods instead of Instance methods in Visual Basic that way I don't have to waste memory and code creating temporary objects to execute methods that don't need instance variables.
I am not sure if you can do that in VB but I know you can in Objective-C by using either a "+" or "-" sign in front of the method declaration. And in C++ (at least I think, I can't remember) you put the static keyword or const keyword in front of the function.How would I do this in VB if it is possible? Or should I just make a separate set of functions that are not members of a class?
I am having an issue trying to figure this out. I am writing a script editor that uses tabs (a tab control) and I want to implement syntax highlighting. My issue is that every sample I can find on syntax highlighting uses
Private Sub RichTextBox_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles RichTextBox1.TextChanged
Public Class Form1 Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load Dim someproc As Process
[Code]...
As I understand it, C# passes parameters into methods by reference. In vb.net, you can specify this with ByVal and ByRef. The default is ByVal.
Is this for compatibility with vb6, or is it just random? Also, how can I specify what to use in C#? I kind of like the idea of passing parameters by value.
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 RepliesI'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.
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?
I see some functions within some code that are:
Public Function GetDataObjects(Of Customer)(ByVal dataset as DataSet)
...
End Function
What exactly does the (Of Customer) do in this instance or mean?
[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 RepliesByRef (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.
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 RepliesI 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.
wads the difference between OptionalByVal and ByVal??how are they used?
View 3 RepliesI 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)
What is the difference between ByVal and ByRef? Please remember to mark the replies as answers if they help and unmark them if they provide no help.Welcome to the All-In-One Code Framework!
View 5 RepliesCan any one translate the following syntax to vb.net.
m_TextBox.Loaded += TextBoxLoaded
m_TextBox.Loaded -= TextBoxLoaded;
private void TextBoxLoaded(object sender, RoutedEventArgs e)[code].....
Private Declare Function ReadProcessMemory Lib "kernel32" Alias "ReadProcessMemory" (ByVal hProcess As Integer, ByVal lpBaseAddress As Integer, ByRef lpBuffer As Integer, ByVal nSize As Integer, ByRef lpNumberOfBytesWritten As Integer) As Integer
[Code]...
This correctly returns the memory value as string. So yeah, now it's just the Single that's causing issues.
ByRef vs ByVal generates errors!?I had a method that used an Object Function Foo(ByRef bar as CustomObject) as Boolean this method generated errors, because some strange .NET Runtime things changed the bar object, causing its Dispose()al.A lot of time spent to understand the thing(where the ... object is changed), until somebody replaced ByRef by ByVal and object wasn't change anymore when passing to this method.As in my case the function Foo does NOT modify the bar, shouldn't ByRef or ByVal have the same effect?[code]
View 4 RepliesAfter installing VS 2010 SP1 I noticed that ByVal keyword doesn't automatically appear after declaring Function or Sub parameters. Is it new feature or bug?
View 5 RepliesI have an old unmanaged dll function and I want to pass an array to it.The dll function expects the array to be passed by reference.Sometimes I can do that and sometimes I need to pass a pointer in a variable.Is it possible to override the declare for the function so that I could pass either the array by ref, or a pointer to it if I need to?
View 15 RepliesIf a function returns a private shared (static) string, or a string declared as a module level variable, is the returned a reference to the shared string's instance or a different string instance having the same value?
View 1 Replies