In C#, you can do this:
new MyClass().MyMethod();
The method is executed and the reference is (typically) discarded since no reference to the object is kept.Is this possible with VB.NET (.NET v4)?
Edit: I suppose this is a better example:
new Thread((x) => doSomething()).Start();
I have several similar classes but only want to instantiate one of these classes dependant on a selection from my main form.
View 4 RepliesI don't know if this has been asked before, but we're having a discussion about it today at my job. Should private variables (that are shared/static) be instantiated when they are dimensioned/defined, or is it a better practice to do this inside of a constructor?
Public Class IpCam
Private Const HOST As String = "http://test.com/url/example"
Private Shared _Example As New OurClass(HOST)which one to use?
[code].....
I'm strictly looking for a language conversion here of this:List<?> I already have a work around I'm just surprised that I can't find the vb.net equivalent of a variable type of a "raw" generic list that takes a wild card.Java's mechanism here enables you to reference a list regardless of what T is.Java even enables you to go further and do things like:
List<? extends Number>
List<? super Double>I tried:
List(Of )
and that did not work. That only seems to work inside the GetType function.
Hi, I'm just beginning to teach myself how to do OOP in VB 2008 Express. I have a quick question after seeing a video online.Is a VB variable the equivalent of an 'instance' in Flash and a VB object like a 'symbol' in Flash? Is this what it means by a variable being a reference or pointer to an object and not the object itself?
View 5 RepliesI have a class:
Form
Public Class Form1
Dim teamlist(2) As team
Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
teamlist(0) = New team(1, "one", "First")
[Code] .....
Error I'm getting is too many arguments.
I am having some real issues with this one. I have a class which contains two other objects...but I cannot seem to instantiate those sub objects. Here is the code for my class:
Option Explicit On
Public Class Boot
'A collection of Heads and Shells
[Code]....
Notice the count for my two objects, Ohead, and oShell, is zero. Im not sure why this doesnt instantiate properly, as I believe is what is going on.
I can't find what's going on with the following nHibernate HQL.
here's my VB.Net code:
Return _Session.GetNamedQuery("PersonAnthroSummary").SetInt32(0, 2).UniqueResult()
My Named Query:
[code].....
I just like to know if how can i do single form instantiation upon loading my Form..upon loading my MainForm it automatically detect if that MainForm is still exist..ive try putting my code in the contructor of my MainForm..i check through the process in the task manager if that MainForm is still exist..but i think this is not the good idea bcoz..the MainForm takes several seconds to appear..and i think this is bcoz i loop through the process.
View 1 RepliesI can insert values into a VB.NET Dictionary when I create it? I can, but don't want to, do dict.Add(int, "string") for each item.
Basically, I want to do "How to insert values into C# Dictionary on instantiation?" with VB.NET.
var dictionary = new Dictionary<int, string>
{
{0, "string"},
{1, "string2"},
{2, "string3"}
};
What I want to do is pass a Type to another object's constructor, where the other object creates a new instance of Type. I can create a constructor with a parameter declared as System.Type without problem, but when I try to instantiate it tells me there is no such type.
Public Sub New(targettype As System.Type)
Dim Test As System.Windows.Forms.Form = New targettype
End Sub
i have an application that have been working correctly, but sudenly shown an error as this: Error at create form, Exception.InnerException. When i execute debuger show error at the instantiation variables as xmldocument, control or decimal.
View 1 RepliesI have Form with the following code -
[Code]...
So I'm just trying to understand why someone would want to use the shorthand property instantiation
Public Property CarModel As String <-- property
As opposed to
Public CarModel As String <-- variable
Is there a way to call functions within a class upon instantiation of that same class? Basically, I have functions within a class, but I want to automatically call some of those functions simply when there is an instance of the class created.
Basically, I have this structure:
Dim instance as new class
instance.function1
instance.function2
[Code].....
VB 2008 .NET 3.5 Suppose we have two classes, Order and OrderItem, that represent some type of online ordering system. OrderItem represents a single line item in an Order. One Order can contain multiple OrderItems, in the form of a List(of OrderItem).
Public Class Order
Public Property MyOrderItems() as List(of OrderItem)
End Property
End Class
It makes sense that an OrderItem should not exist without an Order. In other words, an OrderItem class should not be able to be instantiated on its own, it should be dependent on an Order class to contain it and instantiate it. However, the OrderItem should be public in scope so that it's properties are accessible to other objects. So, the requirements for OrderItem are:
[Code]...
I am getting the error:"Range variable 'sender' hides a variable in an enclosing block or a range variable previously defined in the query expression."for this
Imports System.Data.SqlClient
Imports System.Linq
Public Class Form1
[code]....
I can select any other item from the table without the error. "sender" has the same properties as "receiver" in the SQL table.
I receive the error -
[Code]...
Public Class Form1
Dim x, c, number(0 To 19) As Integer
Dim s As Integer
[CODE]...
The variables in the brackets [example] do not actually have brackets in them in the original code. These are where the issues are. For both variables, it says, "The type for variable [variable] will not be inferred because it is bound to a field in an enclosing scope. Either change the name of [variable], or use the fully qualified name (for example, 'Me.[variable]' or 'MyBase.[variable]')." Now, I'm not entirely sure if this is a stupid question or not, as I'm used to VB '98 because that's what we use in my programming class at High School. let me know why this won't work.
-Note: The intention of this program is to continually loop the generation of numbers for this list until I tell it to stop. Button1 ends the program, Button2 generates the list one time only, Button3 is supposed to loop the generation of the list, and Button4 is supposed to end the loop, but not the program.
Say that i have the following code that parse about 20k records from the DB.
Code #1
vb.net While reader.Read()
list.Add(If(Integer.TryParse(reader(0).ToString, 0), Integer.Parse(reader(0).ToString), 0))
End While
And then another code which does the very same thing but it seems to be a little cleaner.
Code #2
vb.net While reader.Read()
Dim storeowner As Integer = 0
Integer.TryParse(reader(0).ToString, storeowner)
list.Add(storeowner)
End While
This is what i am confused about; does the compiler creates a new variable automatically when i use the if statement without strictly declared variable? What approach is better in sense of performance?
I am looking for a good resource on variable naming conventions to illustrate variable type and where variables are declared. So I will have public variables, Private variables, private or local variables. I also may want to declare variables with the same name in different class code (i.e. in the code behind different forms). I am assuming good coding would dicatate a prefix for declaration location.
View 4 Repliesi have this error in the line of with xl.active......Object variable or With block variable not set.
Dim xl As Object
xl = CreateObject("Excel.Application")
With xl.ActiveSheet.QueryTables.Add(Connection:= _
"TEXT;C:Documents and SettingsUserDesktop429MEDICA2.TXT", _ Destination:=xl.Range("$A$1"))
[code]....
Now I have the need to get a current value from a bindingsource in a property of a user control.In a previous thread I had tracked down the "Object variable or With block variable not set" to the return in the Get block of a property. At the time I was only using the Set so I just commented out the offending code until I needed it.
[Code]...
The error does not occur during a system compile, only upon saving the container object of the user control. As I said the Set works correctly, only the Get causes the error.I would like to know what I am missing/misunderstanding and am open to other suggestions of handling retrieving the current value of a bindingsource in a user control.
Using Visual Basic 2008 Express. I need to pass a variable to another form. Or else make the variable visible to both forms.
View 4 RepliesI am using vb2008.net express,I test vs2005term it work, can any tell me what is the input variable and output variable of this terminal?how to catch the input and output variable to a textbox1 for sending and a textbox2 for receiving when I press send button? is that possible?
View 1 RepliesI have the following code that I am using to parse out a test file. I am getting variable conversion error in Sub Main() when I assign file = Read(). The return value of Read() is a TextFieldParser type. How do I assign the proper variable type to "file" so I can write the output to a text file?
Function Read()
Using MyReader As New FileIO.TextFieldParser("C:UsersColinDesktopParse_Me.txt")
Dim currentRow As String
[Code].....
I have the following code but I get blue squiggly line in cnn and when i point my mouse pointer on it i see this message "Variable 'cnn' hides a variable in an enclosing block"
Private Sub BtnLockUnlock_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnLockUnlock.Click
Dim IsLocked As Boolean = FpSpread1.ActiveSheet.DefaultStyle.Locked
[code].....
I have the following code passing a dataView variable to a function and I am getting the following warning:"Variable 'cl' is passed by reference before it has been assigned a value. A null reference exception could result at runtime."
Function Editclass()
Dim cl As DataView
Bindclass (SqlConnection2, cl)
[code].....
i had a class called Tag with a structure like:
public class Tag
private _members
public properties
public shared database_methods
end class
this class was tailored for mysql database. i'm currently adding access 2007 support so i split tag into tag and tagdata with structures like:
[Code]...
I'm having trouble tracking down what is wrong and causing the above error. This only occurs when saving the design view in VS 2012. The code builds and runs fine.Full error text:Code generation for property 'CompanyValue' failed. Error was: 'Property accessor 'CompanyValue' on object 'ContactViewUC1' threw the following exception: 'Object variable or With block variable not set."
CompanyValue definition in ContactViewUC:
Public Property CompanyValue
Get
[code].....