I understand that an array variable contains a reference to an array object - it is a reference type. A string variable is also a reference type.So, if I make a copy of either one, a change to the copy should also change the result I get when I look at the original because both refer to the same object.
View 5 RepliesI understand that an array variable contains a reference to an array object - it is a reference type. string variable is also a reference type. So, if I make a copy of either one, a change to the copy should also change the result I get when I look at the original because both refer to the same object. In the following code, I expected to see "Whoooy" as the result for original and copy for both the array and the string. It works with the array but not the string.
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I have a class with a Property called 'Value' which is of type Object.Value can be of any type, a structure, a class, an array, IList etc.My problem is with the setter and determining whether the value has changed or not.This is simple enough for value types, but reference types and lists present a problem.For a class, would you assume that the Equals method has been implemented correctly, or just assume that the value has changed every time the setter is called?If I did assume it's changed, then perhaps I should assume it for value types as well, so that the behaviour is consistent.
View 2 RepliesThe difference between reference types and value types is often confusing for beginners due to not understanding what a variable of value type actually holds. We know that:Value types store the actual valueReference types only store the reference to the object
View 4 RepliesI'm still working on the code in this thread [URL] and as I mentioned in that thread, I thought that passing objects around between methods would probably be bad for performance (perhaps not really noticeably at first but maybe if I did it enough then it could have an impact).
1. When you pass a reference type to a method using ByVal then what is actually 'copied' ? I understand that ByVal copies the object into the local method that you are calling where as ByRef passes a reference to the actual object so you can work with the original object. So when you have a Reference type and you pass this ByVal then does copy the entire object or does it just copy a 'reference' to the object?
2. When working with an object that relates to a 'physical' item, such as a file on disk or a network stream between two connected machines, then what happens when you pass it around between methods (this might be irrelevant depending on the answer to the first question) ? I mean if I have a NetworkStream object that represents the data stream coming from a remote computer, if I then pass that ByVal into another method then does that mean I am still working with the same data stream or a copy of it or what?
I'm integrating one of our apps with a third-party provider's web service. I've added the service reference, but when I go to dimension a var as one of their types, the types aren't showing up for me in Intellisense. I'm using VB.NET/VS 2008 on Windows 7 and a 2.0 Framework web site running on local IIS. I have imported System.Web and System.Web.Service in my codebehind. I also made sure to check the "Always generate message contracts" checkbox.Types not showing up for service reference
View 2 RepliesReading a book, the following examples are given regarding value and reference types. This example is noted as a value example. ptY display {x = 10, y = 20}
Dim ptX As New System.Drawing.Point(10, 20)
Dim ptY As New System.Drawing.Point
ptY = ptX
ptX.X = 200
Console.WriteLine(ptY.ToString())
This example is noted as a reference example. objY displays "Hello Test".
Dim objX As New System.Text.StringBuilder("Hello World")
Dim objY As System.Text.StringBuilder
objY = objX
objX.Replace("World", "Test")
Console.WriteLine(objY.ToString())
The idea is simple enough, but I just can not tell the difference between the two. Could someone explain how the heap, the stack and the New keyword play a role in accessing directly and indirectly objects and variables?
Is it okay for a structure variable to hold a small number of reference types? I thinks it's fine because the pointers themselves are not that big, regardless of what they're pointing to. But I never did fully figure out the whole heap/stack thing, so I'd like to make sure.
View 6 RepliesFirst post here so Im sorry if im posting in the wrong place. Im trying to build a simple poker game which requires the program to recognise hands of each players. Luckily there are 3rd party solutions such as pokereval. However my problem comes when i try to convert a C# ported version of pokereval by Keith Rule, into vb.net. The following error shows up referring to the line with the *.
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I have a copying error with my program. I am trying to copy the internet cache folder, and the error states that some files cannont be copied (read only maybe?) How can i make it copy, or just skip the uncopyable files?
My.Computer.FileSystem.CopyDirectory(Environment.GetFolderPath(Environment.SpecialFolder.Internet Cache), "d:My Documents")
I need to compare two dictionary values if the types stored are equal, this is what i have
if gettype(Args(key)) = gettype(argtypes(key)) then
'' do something
end if
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I am receiving this error: Reference to a non-shared member requires an object reference on the code I've
bolded within the code body. Here is my code:
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I get this error:Reference to a non-shared member requires an object reference.When i compile on the following code section:
Private Sub statusBarToolStripMenuItem_Click(ByVal sender As Object, ByVal e As EventArgs)
ToolStripMenuItem.Checked = Not ToolStripMenuItem.Checked
statusStrip1.Visible = ToolStripMenuItem.Checked
when I do something like this: Process.Start [URL] it says that error only on Form2 not Form1.
View 2 RepliesError 'Reference to a non-shared member requires an object reference'?I want to know what a non-shared member is.
View 2 RepliesI am opening frmB (variable for FormB - the actual form) from frmA. From btn1 I open frmB like this:
frmB = New FormB()
frmB.Show()
From btn2 (frmB is already open) I bring frmB to the front from behind frmA:
FormB.Show()
FormB.BringToFront().
No problem so far. Now I need to pass an arg to frmB. This is where I am having the problem.
from btn1 (in frmA) I do this:
frmB = New FormB(myArg) '--pass myArg to constructor of FormB -- no problem here
frmB.Show()
then from btn2 -- this is where I have the problem
FormB.Show()
FormB.BringToFront()
I tried placing myArg in FormB.Show(myArg) but that did not fix the problem. What is the correct way to pass myArg to FormB (frmB) in this scenario? Do I need to share FormB or frmB? How do I do this? "frmB" is frmA level variable.
why i am getting an "reference to a non-shared member requires an object reference" error on format.Yesterday gets the previous days date and presents it in a yyyyMMdd format.vsettlementDates takes the "Yesterday value and requests data from it.
Dim Yesterday As String = format(Today.AddDays(-1), "yyyyMMdd")
Dim vSettlementDates As String = (Yesterday)
I am getting the following error:
Error 1 Reference to a non-shared member requires an object reference. (on WindowsIdentity.Groups)
Here's my code from that uses the WindowsIdentity.Groups property to display the identity references for the groups the current user belongs to. This code is part of a larger example provided for the WindowsIdentity class.
Public ReadOnly Property Groups As IdentityReferenceCollection
Get
Dim irc As IdentityReferenceCollection
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" GridView1.datasource = _MyUsers.Reference to a non-shared member requires an object reference." error. WHat's wrong with this code
<%@ Page Language="VB" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
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I have the following code below, how the line where it says : For Each c As councillor In councillorList i get the error: reference to a non shared member requires an object reference. Can someone please advise where i am going wrong? [Code]
View 2 RepliesAlright, so im getting this error:Reference to a non-shared member requires an object reference.This is the bit of code the error is pointing to:My.Settings.Bookmarks.Add(WebBrowser.Url.ToString)Why is it giving me this error?Its saying WebBrowser.Url is the problem.
View 1 Repliesim sure it is something really simple. Im by no means comfortable with VB. The below code is not mine but i have altered it for my needs. However im getting a couple of errors.
Reference to a non-shared member requires an object reference. I have underlined the errors in the code and they all refer to the above description
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Im trying to create a login page which accesses a mysql database I keep getting this error: reference to a non shared member requires an object reference
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Can I reference a dll programatically in VB.net? Or change the Local Copy path for a dll reference?
View 1 RepliesHow do I fix the following error: Error 1: "Reference to a non-shared member requires an object reference."
On Line:
shortCut = CType(WshShell.CreateShortcut(creationDir & "" & shortcutName &
".lnk"), IWshRuntimeLibrary.IWshShortcut)
Here's my full code sample (if needed for context):
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I am getting the following error when I call another form from Form1 and fill out the text boxes and Press Ok button. For some reason I cannot access the datatable (dt) from Form1. It gives me the following error: Reference to a non-shared member requires an object reference
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what is the matter with this
Public Sub showdataset()
For Each dt As DataTable In dsEvents.Tables
Response.Write("<table border='1'>" & vbCrLf)
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I am using this exact code on another form in the same project without an issue, just with a different data source. Any ideas?
EDIT: Never mind, seems like it was a stupid naming scheme and VS was adding a bindingsource with a different name than I wanted.
I have two forms form one have one listbox and one checkedlistbox and form2 have only checkedlistbox
on form one checkedlistbox is being updated by listbox_SelectedIndexChanged.
how can update checkedlistbox on form 2 when listbox_SelectedIndexChanged on form1
when i use form2.checkedlistbox.BeingUpdate()
I am getting this error for Login.Show() here:
Imports Microsoft.VisualBasic.FileIO.FileSystem
Public Class Update
Public Sub CheckUpdate()
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I am also getting this is every other form when using the Login form, along with Login.Close(), and Login.Hide(). I haven't tested any other ones.