how to declare scope for variables outside their class?
Here's what i have in a class known Create_User:
Public Class Create_User
Public conn As New SqlConnection(My.Settings.HotelConnectionString)
Public usercmd As SqlCommand
[Code]....
How can i increase the scope of these variables to be used in another class? I dont want to keep declaring them again and again.
ok I have two procedures:This is for the tick of a timer
Private Sub Timer1_Tick(sender As System.Object, e As System.EventArgs) Handles Timer1.Tick
intTickCounter = intTickCounter + 1
[code].....
I'm moving from VB6 to VB.net and there are a few things confusing. In vb.net, your program just automatically has a form, now the form in in a class and so it may or may not be there. In vb6, the main subroutine controls program flow and I don't see that in vb.net. However, my biggest problem is that I have a com dll that has a connect class with events. I need to be able to access these variable outside of that class. I don't understand how to do that. I can't seem to declare public withevents outside of the class and in the namespace so it can be shared with other code. Its say "not valid" in Namespace.
So what is the best way to do that. Do I create a set/get property for the class that holds this value? And, if I do that, is the connect class automatically instantiated as a part of the COM dll? Right now I don't instantiate the connect class, I assume the application does. But I'm not sure exactly how the property of the class would be set...perhaps I would need to call the property set from the on-connection method. Anybody know what the answer to these two questions are and this 3rd one? How can I have a variable that has "events" have scope across the entire project?
I have a public variable which seems to be going out of scope. I am confused as it has been dimensioned as a public variable: Public xlCell as As Microsoft.Office.Interop.Excel.Range
I originally had all my code in the same module in the same project and it was wrapped within a For/Next Loop (Example 1). I decided to clean up my code and make it more modular (Example 2). All the code is still in the same module in the same project.
Upon doing so, my public variable is not recognized in any of the private subs that I have created. I keep getting the following error: Message="Object reference not set to an instance of an object." When I test the variable using ?IsNothing(xlCell) in the Main Sub I get False in the main sub. this tells me te variable is recognized. However as soon as the Call SelectCaseSub() is triggered, I get a True value for ?IsNothing(xlCell). Why is this? Shouldn't this variable be in scope regardless?
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I'm trying to create a simple media player that will scan a directory for certain filetypes, add them to a playlist then play a random playlist entry - changing every x seconds.I figured this would be simple in VB and, to an extent it was. I have the code running that chooses the directory and plays the random file.I just need to now make this repeat every 30 seconds or so.I have all the coded attached under the sub for the 'open' function of the player so it's quite flat. I think I need to use a timer here, to trigger the routine to pick and play the media every 30 seconds?In doing this I think I need to break the variables out of the function I currently have as they need to be shared between the timer loop function and the central 'creating file list' function.
I'm having trouble - I'm no coder (as you'll tell!) and although getting this far was easy I'm now (I think) bumping into threading / variable scope issues which are a bit of a brick wall.I've tried making the variables public / global by declaring in the class rather than the sub but I get errors at runtime. Presumably because of how I'm creating the windows media objects? [code]
where I should declare my variable when using forms and the scope in my test code.
In my code below I have declared variable x in my form1 which can be printed in form2.
But when I create a structure in form1, initialize an array of the type protorec and try to assign values to cards(1).firstname etc... I get a "declartion expected" error.
Why does it work for x but not for cards(x) my array of records?
Public
Class Form1
Public Structure protorec
[Code]....
I have put together the following code to illustrate the problems I've been struggling with:
Public Class OuterClass
Private _OuterProp1 As Boolean = False
Public Property OuterProp1 As Boolean
[code]....
I need to be able to refer to outer class properties and variables in an inner class, and I need to have a variable in one inner class set in a different class. I've tried Public, Private, Protected, Friend and all kinds of combinations of them, and I can't figure it out.
Below is example code of what I want to do:
Public Class Test
Sub New()
Dim cool As New B
cool.Doit()
[code]....
I'm working with legacy data, which often brings me one information splited in multiple columns. I'm trying to reproduce the following SQL query.[code]This own statement will run into the following exception:Variable 'line' of type 'SomeTable' referenced from scope '', but it is not defined. Any directions? I'm trying to avoid magic strings, but I'm always giving up to it (as using HQL the concatenation expression + like function works like a charm).
View 1 RepliesI want to create a new instance of a class when I click on a button, but I need to interact with members of that class using other controls on the form, so I need the class to have a global scope. I know I could call the new class in formload, but the class creates certain variables that need to be current. If it is done on formload, the variables wouldn't be current, because if the class is created at formload, it would have different info at that time. Surely, there must be a way to create an instance of the myClass from within a sub that is accessible from other subs of the same class.
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I am struggling to do what i want with classes at the moment as they are killed off at the end of a method, can somebody let me know how to make the classes live until i tell them to die? so that i can create one and refer to it from another method at another time? For example On form load i create a class Dog.Then later on i want to get info from the Class Dog. But it is no longer instantiated
View 6 RepliesHow to make my class NotInheritable but Inheritable from within the library scope (friend)
View 5 RepliesI have some code and there are 2 errors which I don't understand I have tried all sorts...
1)The type for variable 'Index' will not be inferred because it is bound to a field in an enclosing scope. Either change the name of 'Index', of use the fully qualified name (for example, 'Me.Index' or 'MyBase.Index').
2)Function 'GetNewPhrase' doesn't return a value on all code paths. A null reference exception could occur at run time when the result is used.
I can't get it to work..
This program was created with vb6 to find and remove empty folders. i converted this program to VB.NET code and it isn't working like it should.. it seems to stop scanning at 'C:\documents and settings' instead of scanning other folders in other directories...Does this code look right? I can provide the entire program if needed... I just want to know why it isn't scanning like it should. Btw im switching from vb6 and trying to learn vb.net.. vb.net is a lot different..
Private Sub ScanForEmpty(ByRef vFolder As String)
Dim nSize As Integer
System.Windows.Forms.Application.DoEvents()
If bExit Then Exit Sub
[code]....
I get this message at the bottom:Warning5 The type for variable 'FolderObj' will not be inferred because it is bound to a field in an enclosing scope. Either change the name of 'FolderObj', of use the fully qualified name (for example, 'Me.FolderObj' or 'MyBase.FolderObj').
This webservice is almost converted form VB to C#, except I get this error shown below on the DataRow arow object when I use it in the foreach statement below to populate the Results Class with a DataSet Object...
Error: A local variable named 'arow' cannot be declared in this scope because it would give a different meaning to 'arrow', which is already used in a 'parent or current' scope to denote something else
using System;
using System.Web;
using System.Collections;
[code]....
Once time, me needed to compile the library with different code inside class which determined with prroject wich inherits this library At first I tried in project declare #const and in library to use condition with #const,
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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:
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Create a class named Service. Inside the Service class, declare a class variable named Started. The datatype of this variable is Boolean.Public Class Service Dim started as Boolean End Class Create a class named Server. Inside the Server class, declare a dynamic array that can contain elements of the type Service.(Note: For convenience, both the array and the variable Started can be accessible from a client program that creates an instance of Server and Service respectively)
Create a constructor for the Service class. When the constructor is executed, it will set the value of the class variable Started to True. Create two new classes: WebServer and DatabaseEngine. Both of these classes inherit from the class Service. Inside the Service class, declare a Sub procedure (method) named Terminate. This method should display the following text Service stopping in a message box when executed.This method can be overridden in classes that inherit from Service class.
Inside both the WebServer and DatabaseEngine class, override the method Terminate inherited from their base class Service. Both methods should first call the base class Terminate method. The messages Web server stopping and Database engine stopping should also be displayed in a message box when the Terminate method for the WebServer and DatabaseEngine are called respectively. These messages should only be displayed if the Started variable inherited from their base class is not equal to False.
Inside the Server class, declare a method named Shutdown. This method does not return any value. When executed, it will call the Terminate method for each of the Service instances (if any) in the arrServices
array. You should call the Terminate method within a For Each loop that loops through the elements of the arrServices array.
In the Sub Main method, create an instance of the class Server. Set the size of the arrServices array in
your Server instance to contain 2 elements. Create first a WebServer instance and then a DatabaseEngine
instance into this array. Call the Shutdown method from your Server instance.
I want to created a nested class that can only be visible to and instantiated from the parent class.But I also want to be able to use an instance of the nested class through a public variable of the parent class.I tried making the nested class private, or making the nested class' constructor private, but it won't compile.Is it possible to do this in .NET?
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I have procedure (Import) that calls a for a new instance of frmImportData. I also have a class name clsBatch that has a data table property called prpParametersTable.For some reason, I get an error (indicated below with ERROR>>>) when trying to assign prpParameterTable to cv_dtImport2. The error states "Object reference not set to an instance of an object.". Why does this error not happen when I assign dtBP to cv_dtImport1? Both cv_dtImport1 and cv_dtImport2 are equal to Nothing and in my Import procedure dtBP = prpParametersTable.
Public Sub Import(ByVal clsB As clsBatch)
Try
Me.cv_clsB = clsB
[code]....
I have three class files, accounts.vb and transactions.vb in addition to my form.vb. I am unable to retrieve a member variable from on class from inside the other. When the combobox index changes, the program loads the correct account (checking or saving) from two different sequential files. I don't think I have the calcBalance procedure in the correct class file. And that is what I am having trouble with. Accessing it to display it. [Code]
View 1 RepliesWhat i'm trying to do:
I've got a library which includes a class:
Class Human
End Class
and another class which refers to the human class
Class ASD
Private somevar as new Human
End Class
Ok now i've got a problem, i wish to rename my class Human, to Man. i've got to change Human to Man 2 times, which is OK but the problem is that in the real case, its not just 2 times, its like 500 times or more.
Well its something like a PHP on Javascript.
the following shows the solution of what i'm trying to do, but its in another language PHP/Javascript:
note: in php $ sign declares a variable, echo writes the variable out
CODE:
Is there anyway to do that with VB?
I have the following code:
Option Explicit On
Imports System.DirectoryServices
Imports System.IO
[code].....
The code below works for the class that I hard coded "XCCustomers" in my RetrieveIDandName method where I use CType. However, I would like to be able to pass in various classes and property names to get the integer and string LIST returned. For example, in my code below, I would like to also pass in "XCEmployees" to my RetrieveIDandName method. I feel so close... I was hoping someone knew how to use CType where I can pass in the class name as a string variable.
Note, all the other examples I have seen and tried fail because we are using Option Strict On which disallows late binding. That is why I need to use CType.I also studied the "Activator.CreateInstance" code examples to try to get the class reference instance by string name but I was unable to get CType to work with that.When I use obj.GetType.Name or obj.GetType.FullName in place of the "XCCustomers" in CType(obj, XCCustomers)(i)I get the error "Type 'obj.GetType.Name' is not defined" or "Type 'obj.GetType.FullName' is not defined"
'+++++++++++++++++++++++++++++++
Imports DataLaasXC.Business
Imports DataLaasXC.Utilities
[code]....
How does a class get the name of the variable that instantiated it?[code]...
View 9 RepliesI have 2 subs in my class. I need to use the values in the variables in the first sub in my second sub. like this.
Public sub test1()
Dim one as double = 12
Dim two as double = 10
[CODE]...........
But I do not remember how to do it.
I have form1.vb and class1.vb
Code removed
What I am trying to do is very simple now. Pointx and Pointy in Class1 is underlined. How do I get that variable value (which the form1 finds) into class1.
I'm getting an error in .net when trying to declare a Public class on my code behind page.
Partial Class _Default Inherits System.Web.UI.Page
Public someVariable as integer
Public someClass as className
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load [...]
The error I'm getting is BC30508: 'someClass' cannot expose type 'className' in namespace '<Default>' through class '_Default'.The goal here is accessing the class properties in script blocks on the aspx page like this <%=someClass.classProperty%>
I'm not sure if I'm trying the right methods (I've tried several ways of declaring the public class) or if it can even be done..
I want to do this: [URL] but in VB. I believe that is for C# I have 2 classes.
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I know I've been asking too many questions lately and I do apologise for that. I am trying to learn the basics
how to access the variable from another [Code] I need to call the variable invoiceno in the class xmlserializer using ord1 and assign the value which the user enters during the runtime.
View 6 Replies
