I am writing a program and i need to declare matrices but there will be a different number to declare everytime the program is run so I was wondering if anyone knew how to declare them inside a for loop
eg.
For i = 1 to NumberOfMatrices
Dim matrix i (5,5) As Double
Next
Sub Application_Start(ByVal sender As Object, ByVal e As EventArgs)
Dim chatters As List(Of Chatter) = New List(Of Chatter) chatters.Add(New Chatter(New Guid("CD863C27-2CEE-45fd-A2E0-A69E62B816B9"), "Me")) chatters.Add(New Chatter(Guid.NewGuid, "Juan")) chatters.Add(New Chatter(Guid.NewGuid, "Joe")) Application.Add("Chatters", chatters)
[code]....
I am unable to understand last 3 lines that are bold and underlined. Please what is hppening here. Chatter and Chat are two classes defined in App_Code folder. Is there any sight that contains all possible ways to declare and initilaze variables and data structure:
Dim chatters As List(Of Chatter) = New List(Of Chatter)
I have some variables that are distinct by numbers, like in1, in2...If I have for loop, how would I access those variables, using the counter, and attaching it to the variable?I believe in JAVA, you could just use in+ct... where ct is the counter to access the variable.also how could you make a new variable in the for loop?Initially I had variables declare outside of the for loop. The problem was how to access those variables using the for loop.
var_nm1 = in1.Text
var_nm2 = in2.Text
var_nm3 = in3.Text
Dim nmList(2) As Integer
[code]....
This is object oriented programming, and I made the textboxes in1, in2, and in3 using the GUI editor. that was so easy.
Does the memory used in declaring variables are reclaimed by the OS when these variables go out of scope?Does the memory used be released by setting thier value to nothing? if not, then how can I force the garbage collector to run or excecute at a certain/desired time..How about in Windows Forms..How can we make sure that the memory used in initializing and showing forms be released if those forms were closed?
View 13 RepliesI actually came from VB6 and starting to learn VB.NET. I saw this line of code which I cannot understand how it works nor how it goes.
Private MAX_VALUE As Integer = (1 << 14)
I have just been experimenting with nesting classes within a User class I had already created.
E.g.
Friend Class User
[Number of Properties...]
Friend Class Address
[code]....
I get the same error message!!! "Declaration expected". Also I notice the variable's name is not coming up in intellisense. I have not come across this before as declaring an using variables and objects has been straight forward up until now.
The user clicks a button, a new form is generated where the user enters his/her password? How can I keep an in-memory copy of the username?
For instance in web forms, I can just use Session ("User"). How can I replicate this with winforms?
I've created a 30 point wizard. Every step gathers between 1 and 3 variables. I've created a module and publicly declared the variables there. At the end of the wizard, one master form opens, gets all the variables, and displays them on one form. At this point calculations are run too which populates more variables. This works fine for one instance of the process.
the user may want to be running two instances of the wizard at once. Obviously, if the previous wizard is part complete and they start a new one, the variables are going to get crossed or replaced by the new wizard.Is there a way for the variables to be declared publicly but used in multiple instances?
OK, I'm working on a project and i need to access the property of a usercontrol which I have set.Here is the code in the UserControl
Private Color As Color = ColorTranslator.FromHtml("#000000")
Public Property InkColor() As Color
Get
[code].....
What's the proper way to declare variables in a class? I've been doing something like:
'in a class
public shared teststring As String = "first"
'on a code behind
[Code]....
with shared variables loading a second window or reloading the page (without clicking the button) renders the hello world string. so how do I declare variables in a class but make it per instance?
When I am writing a sub or function that does some calculations etc. I often need a loop or a integer variable to count.
An example:
''' <summary>
''' Compare elements with the new data and perform all necessary actions.
''' </summary>
[Code]....
As you can see, variables like timespan, nullCount and seconds are declared within this sub.
My question is, is it better to declare these in the class? I can imagine that would boost performance.
I need to write a simpe calc. program to add, mutiply, subtract and divide. I want to have two textboxes that I enter numbers in and when I click a button, +,-,/ or * a third text box will display the result.Rather than declaring my variables inside each instance of a click event I would like to declare them globally so I just need to perfom the calculation on them and display result. However declaring them globally doesn't work for me. I;ve tried the variables inside the btnAdd click event which works, but as I said I'd prefer to declare them onece globally.
Public Class Form1
Dim number1 As Double = CDbl(txtNum1.Text)
Dim number2 As Double = CDbl(txtNum2.Text)[code]...
recently started converting our project from 1.1 to 2.0
It was fine with the following:
Public ghtAllAppMsgs As New Hashtable(300)
Now it is complaining to change to the following is this the right way:
Public ghtAllAppMsgs As New System.Collections.Hashtable(300)
This is under global.vb class file: here are the imports i already had in this file:
Imports Microsoft.Web.UI.WebControls
Imports Microsoft.Web.UI.WebControls.MultiPage
Imports System.Web
[Code]......
I am new to the forum and new to the visual studio set up and have been working at a practical at home and have ran into some difficulty. The notes say that I am to declare several module variables below the section entitledI have the rest of the form complete but have been unable to locate where I am to place this code
View 1 RepliesI am at a loss to figure out why this code results in 2 errors when I try to Parse it inthe SSMS.
@Collection varchar = Books,
@Title varchar = 0,
@Authors varchar = 0,
[Code].....
I think that I re wrote this query ten times todaday and continue to get errors and don't know what my problem is
There are underlines in red under the 0 in the BookLoanStatus and under all of the parameters in the SQL.
I am new to Visual Studio.NET but very familiar with the old ASP (using DreamWeaver).I am unfamiliar with this system of having seperate files for VB code and HTML, in my Visual Studio project I have a Default.aspx file and a Default.aspx.vb file. Now I want to declare a variable that will be accesible to all my functions on the Default.aspx.vb file. I.e. if a user clicks on one button and it launches a Protected Sub called Button1_Click, I want that button to be able to read or write to that variable and then if a user clicks on another button, I want it to likewise be able to read and write to that variable.So where should these variables be dimmed?
At the top of the aspx.vb file? Before or after the line that says "Partial Class _Default"?Or at the top of the aspx file? (Within <% %> brackets?)
Is it possible for a class of exposing a type for function returns, without allowing users of that class to create variables of that type? A couple usage scenarios:A Fluent interface on a large class; a statement like "foo=bar.WithX(5).WithY(9).WithZ(19);" would be inefficient if it had to create three new instances of the class, but could be much more efficient if the WithX could create one instance, and the other statements could simply use it.A class may wish to support a statement like "foo[19].x = 9;" even when foo itself isn't an array, and does not hold the data in class instances that can be exposed to the public; one way to do that is to have foo[19] return a struct which holds a reference to 'foo' and the value '19', and has a member property 'x' which could call "foo.SetXValue(19, 9);" Such a struct could have a conversion operator to convert itself to the "apparent" type of foo[19].In both of these scenarios, storing the value returned by a method or property into a variable and then using it more than once would cause strange behavior. It would be desirable if the designer of the class exposing such methods or properties could ensure that callers wouldn't be able to use them more than once. Is there any practical way to accomplish that?In formulating a question, it's difficult sometimes to draw the line between complicated usage cases, and simpler usage cases which aren't quite so important. Here's another usage case, and one closer to the one I'd be most interested in (though I'm also interested in Fluent chaining; being able to have something behave like a C++ reference to a value type would be nice, but probably too much work to bother with).I have a type which is somewhat like the Windows registry, in that it is a hierarchical collection of items, each of which may have a string value, an integer value, and/or a nested collection of items. I wish to be able to support the following types of usage:[code]As for the Fluent interface, my thought would be to have the WithXXX properties return a new instance of a derived class which shadows (not overrides!) the WithXXX properties with versions that simply modify the current instance. The return object from WithXXX would be known to be of the derived class, and would thus use the shadowed WithXXX methods, but once it was assigned to a variable, it would be regarded as an instance of the base class, so the next WithXXX would create a new instance.
C++ a stronger concept of value types than C# or vb.net, including the very useful concept of references to value types; it ensures that references to value types cannot be persisted outside the scope of the type in question. Unsafe code in C# can use pointers to value types, but they don't have the protections offered by C++ references.
I'm wondering about the performance differences between imports and inherits in a .net app.I currently program by creating multiple classes that logically define my objects. e.g. a class for customers, users and product.When i want to use these classes in a page i have to import them eg. "Imports Custmomers" and then later in my code i have to create a variable and datatype it before i can use the sub routines and functions from class.I understand from a coding perspective this keeps it all neat and tidy.So my question Would it be not better to combine all my classes into a base class, inherit that base class, rather than import it, when i want to use it and so cut down on the extra declarations and associated code that come from importing a class; and if i did this would it aid performance?
View 1 RepliesI have a base class foo that will be used in multiple child classes of similar but slightly different function:
Public MustInherit Class foo
Public Function bar1() as Something
''// Perfectly OK to change what this method does
[code]....
How do I get the compiler to generate an error when bar2() is overridden by a child class?
i Have two subs
Protected Sub Btn_Click(ByVal sender As Object, ByVal e As EventArgs)
Dim Id as string = MyClass.getID
Private Sub Sub2(ByVal doc As Document)
' in here i need to access the ID from the above sub the Id needs to be in the btn_click sub cos it reates a unike id every time it is clicked.I am trying to capture the id at the time the button is clicked and store it on a variable.
I'm trying to make an application that calls a function to create a timer, but I cant use WithEvents or Private inside of a function or sub, Is there any way to do this?
View 5 RepliesThis is my first post here at Xtreme VB Talk. I just started programming 2 semesters ago. I am currently working on a program but I am having a little trouble with the length. I am trying to take the integer entered in a text box and using it inside the name of another object.
[Code]...
[code]What is the syntax for using variables inside of quotes?
View 3 RepliesWell I am a new to VB.NET, converting a legacy system to .NET world. Recently I have been reviewing the already existing code since I joined the project quite late in the team. I find that there are many shared functions (not shared class) inside many classes. I doubt this may create some problem if two requests ( i.e two different HTTP request to the same method as it's a WCF application, of course exposed methods are not shared but internally called methods are shared) comes to the same shared method and both the calls to the method may have different method parameters/arguments, overwriting each other's arguments. In short, if shared method has a list of arguments which is going to be processed, is there any chance of inconsistencies in the light of multiple access to the shared method via two http requests.
View 2 RepliesWhat is the impact of creating variables using:
Dim ds as New DataSet
ds = GetActualData()
where GetActualData() also creates a New DataSet and returns it? Does the original empty DataSet that was 'New'ed just get left in the Heap?
What if this kind of code was in many places? Would that affect the ASP.NET process and cause it to recycle sooner?
I'm trying to use variables created within a loop, but I'm not sure how to do this. I've searched around on the net and there is a few recommendations to try and put what I require into a function then just call the function.
[Code]...
I'll try to be brief, In short im trying to add together a variable, (name = STRFinValue) within a For loop, I think the syntax should be:
STRTotal = STRFinValue +STRFinValue(f)
But I am very wrong.
Private Sub btnLBTotal_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)
[code].....
how would I do a loop with different my.settings variables?
ie lots of variables
My.Settings.numberofsites = 3
My.Settings.SiteDesc1 = Home
My.Settings.SiteDesc2 = Work
[Code]....
This would give me an error as there is no variable called SiteDesc.... but I actually want it to return SiteDesc1, then SiteDesc2 etc.
I have an xml document on the internet right. Lets say it contains:
<tag>goose</tag>
What I want to do, is when the user clicks a button in my vb form it looks for the "tag" tag and finds the text inside the tags which is goose. Then it sets a label to equal goose, or whats in those tags.
I'm foolin round with stream reader/writer and I'm running into this problem: If I have my if/then statement inside my loop I get a million msgboxes(which I understand why), however if I put it outside my loop, and the if/then returns a false then the whole program freezes up. I can't move my mouse around, I can't click on any objects, ect. Here is what I'm using:
[Code]...
