I'm wondering what will actually change a class, in the sense that serialized objects of this class will no longer be recognized. If the class has reference to shared methods of another class. Will changing such shared methods also change the classes that reference them?
View 3 RepliesI 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 a List(Of AddlInfo) with AddlInfo being an object. I'm trying to pass addlInfoList by reference into a function of another class:
[Code]...
This works if I'm not passing the reference into another class, but when I try to do this, I get the following error: Overload resolution failed because no accessible 'Sort' can be called with these arguments:
[Code]...
I have a function that 2 derived classes use, but the third doesn't, would it make sense to just leave it in the base class, even though one of the 3 derived classes doesn't use it?The only way I could think of disallowing the third class is to basically create an intermediate class that is derived of the base, then the 2 that use the common function are derived off the second class.
Is it possible to prevent the 3rd class from using the function, while letting the two that are supposed to use it, use it?Does that just seem to go overboard, I mean as long as I don't "try" to call the function from the 3rd class, it shouldn't be a problem, I just was interested if there was a way to prevent it all together without a lot of hassle.
I have created a Interface and a couple classes that implement this Interface. I am in the process of developing a Shared Class that utilizes the functions that each of the individual classes have, due to the interface implementation.What i need to know is how do i develop this Shared Class so that way each of the methods within it are restricted to a single data type. This single data type needs to be restricted to any class that has implemented the Interface.
Some examples:
Public Interface IVector(Of T)
Sub Add(ByVal v2 as T)
[code]....
As you can see it would allow me to develop one form, since i have standardized the required Subs/Functions for any class the implements the IVector interface. As i am still in developement, i was wondering if my current understanding of the method generics is correct in its current form or what i would have to do to make the Generic Shared Class work in the fashion that i am looking for in the example implementation.
I have the following class in a .NET class library:
Code:
Public Class JasonTest
Sub New()
End Sub
[Code]....
The .AddNumbers call works fine, but the AddStrings call yields the error 'Object doesn't support this property or method'.
Is there any way to call a shared method from .NET in VB6? I was unable to find any documentation on this.
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?
So I implemented my own form of Enum static classes so I can associate strings to enumeration values. One of the shared functions in each enum class, GetValue, is used to quickly look up the string value from an internal array via the offset. While all of the enum classes implement the same exact function, the data types of their parameters differ, specific to the enums in each class.
So I come to a point where I want to create a generic class that can use any of the enums by passing it as a generic type parameter. But I cannot find a way to constrain type T in such a way to be able to call each enum's GetValue function. This is where an interface would come in handy, but VB.NET forbids interfaces for shared methods.
I have a base class that I could constrain to, but the base class doesn't implement the GetValue method, and I can't define a generic version of it, because I need to rely on shared properties of each child class in order for GetValue to do its thing.[code]..
I have a class like this:
[Code]...
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 got several methods that all need to add items to a single list which will eventually be used to populate a listview. I thought about declaring the list at class level so that all of these methods could access it, but it didnt really make sense as the only methods that access this list are Shared methods, so I didnt think it was worth having a list just sat there for the entire time that any instances of the class are created, when in a lot of cases the list would not be used.
So what I ended up doing was just declaring the list in the Shared method that then calls these other methods that need to add to the list, and for each of these methods it calls it passes the list in as an argument. The methods can then add items to the list and as the list is a reference type it updates the underlying list object, so once all of the methods have been called then the list in the calling method is up to date and can be used. Then when that method exits, the list is no longer in scope and so is removed from memory. This all works fine, but it feels a bit... wrong. Would it be better to just declare the list at Class level and not be bothered about the small overhead of the list always being in scope when instances of this class are created that will not even use the list?
EDIT: Actually, thinking about it.. because the methods that use the list are shared then the list would need to be shared as well if it was at class level - so the list would not only be around when instances of the class are created, but all of the time. So it will just be sat in memory for the lifetime of the program wont it? I assume this could make a noticeable impact on memory usage after the list has been filled with data, so I guess if I went down that route then I would have to make sure I cleared the list once I had populated the listview. This is another reason why it just seems much easier and more manageable to declare the list as a local variable in the shared method that then calls the other methods that also add to the list.
In my code I use two classes. One contains the UI form, the other containsa method to write to a file. During coding I found out some behaviourwhich I don't understand. The code below shows (what I believe to be)the relevant part. The file writing part is substituted by a MsgBox for simplicity.I have the following controls in one form:
NumericUpDown
Button
With the following classes and methods:
[code].....
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:
[Code]...
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
[Code].....
" 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">
[code]......
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
[Code]...
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
[Code]...
How 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):
[Code]...
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
[Code]...
what is the matter with this
Public Sub showdataset()
For Each dt As DataTable In dsEvents.Tables
Response.Write("<table border='1'>" & vbCrLf)
[code].....
[Code]...
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()
[code]....
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.
I have added one class under namespace BusinessLogics. I have inherited System.Web.UI.Page to class and showing error as 'end expected' in
System.Web.UI.Page
Namespace BusinessLogics
Public Class BllUploadImages Inherits System.Web.UI.Page
End Class
End Namespace
How can i remove my error.