Is it at all possible to declare variables dynamically? Something like Dim Answers & i As ArrayList. What I'm trying to achieve is putting one or more answers to a question into an array. Or should I really be looking at a mult-dimensional array to store the question number and answer? How would I add to and access a multi-dimentional array? Anyway, here's the section of code:[code].......
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trying to figure out how to declare items here. here is the
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I have searched online for a few hours to try to figure out how to do this, but nothing I found really makes sense, so could someone please tell me, in a simple way, how to do this?
Let's say I have a text box that the user fills out, named textbox1. And I have a combo box, named combobox1, which contains the choices A, B, C. And then I have a button named submit_button.
Each time that the user clicks submit_button, I would like to dynamically create a new variable. This variable should be named the same as textbox1.text, and should contain the value of combobox1.
For example, if the user types "blue" into textbox1, and chooses value "C" from combobox1, and then clicks submit_button... then the following variable should be dynamically created, like..Dim blue as String = "C"
And then, after that, if the user types "red" into textbox1, and chooses value "B" from combobox1, and then clicks submit_button... then another variable should be dynamically created, like...
Dim red as String = "B"
And each time the user submits new information into the textbox and combobox, a new variable should be created.Is it possible to have the program automatically create variables like this? If so, how?
My actual project is much more complicated than this, of course, so the above is just an example. But if I could figure out how to solve the problem in this example, I could figure out how to solve the entire project.
I'm new to VB.NET programming.What I'm confused about is the different ways one can declare a variable.Would someone please explain the difference between the two declarations below? [code]
View 2 RepliesHow I can declare global variables in vb.net that I can access them in all windows of my application?
View 5 RepliesI am needing help in understanding how to declare variables properly. I am needing to write as program that calculates the commission for a sales person. I keep getting a error listed below. I thought I declared the salestextbox, costtextbox as integers correctly to use them in the calculation. I Copied my code below also. I have reread the chapter again and I am still lose.[code]
View 3 RepliesI have the following situation, can anybody help me in that?Following is a "pseudo" code of what I want to do in VB using VB.NET 2005:
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How can I define the datatype of an variable dynamically. I read out data from a file. In the file it is specified, if the raw-data is interpreted as single, integer or .... So my idea is: To check, what datatype is in use and then declare an array with this datatype to store the data there.
View 2 RepliesWhat happens if I do: Dim x As New Int32? Is a object of int placed on the heap? If it is, maybe your application would be able to access global variables faster if they were reference types.
A global variable as an value type should be somewhere at the bottom of the stack most of the time and it might take more time to get to this then to get a object from the heap. Unless it's the same story with the pointer of this object is also at the bottom of the stack of course.
I am making a game that involves moving picture boxes automaticly i can get the boxes moving but I need them to be object orientated but when I try to make it a class i am not to sure how to declare the veriables to make it work. [code]
View 3 RepliesThis is a VB.Net newbie question. I'm confused at the different ways to declare and define variables.Here's an example:
Dim URL As String = http://www.c-sharpcorner.com/default.asp
Dim request As HttpWebRequest = WebRequest.Create(URL)
Dim response As HttpWebResponse = request.GetResponse()
[code]......
I put "isolated context" in quotes because I don't know what else you would call it. Basically, in C#, you can do this:
{ int i = 0; }
{ int i = 1; }
The curly braces create an isolated context which allows you to declare two variables with the same name in the same method or property logic. Is this possible in VB.NET? Also, what do you call this aside from an isolated context?
At the head of a module, I wish to declare some global variables for use in various subs/functions.
What is the difference between.Dim x as string and Private x as string / Public x as string, and when would I use one over the other?
When and why do you declare variables in the Public Class Form1 section?
View 1 RepliesI'd like to get a more refined programming style and I was wondering if any of you might give me a hand...(How to declare public variables, constants, functions...in a proper way),is there any useful link or pdf document I could have a look in order to improve my style?
View 5 RepliesI am taking an online class and I am having trouble getting my solution to work. My assignment is as follows: In the function, declare variables for the average score and the letter grade. Calculate the average, use If/ElseIf statements to determine the letter grade, and return the letter grade.
Create a subprocedure for the Click event for the btnDisplay button. It should call the CalculateGrade function with three arguments (the three test scores from the text boxes), and display the returned value in the lblGrade box.I have looked all over the internet and have had no luck finding an example to look at I am taking an online class and I am having trouble getting my solution to work. My assignment is as follows:
In the function, declare variables for the average score and the letter grade. Calculate the average, use If/ElseIf statements to determine the letter grade, and return the letter grade.
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What I'm supposed to do is declare two module level String variables name strCaptital and strChoice and I did that. At least I think I put them in the right place, however what I'm not sure what to do is and I started is that I'm supposed to code each state radio button's click event procedures so that each assigns the appropriate capital to the strCapital variable and then each removes the contents of the lblMsg control.url...
View 3 RepliesI am teaching myself VB, and when I try to run this program, I am getting "An error occurred creating the form. See Exception.InnerException for details. The error is: Object reference not set to an instance of an object." If I was to declare the variables inside each event handler, the program runs, but why won't it run when I make the scope public? Seems repititous having to declare the variables in every event handler. [code]
View 7 RepliesI want to monitor more than 10 folders on different machines by using SysTemFileWatcher. I create a class called Watcher for doing monitoring. So, for each folder I have to call that class once with a new thread. I want to name each thread with its own name like: T1, T2, T3 ... for easier controlling them. It is not nice if I declare each thread like:
Dim T1 as Thread =new Thread(Address of Watcher.StartWatcher)
Dim T2 as Thread =new Thread(Address of Watcher.StartWatcher)
...
Dim T18 as Thread =new Thread(Address of Watcher.StartWatcher)
How can I declare thread names dynamically with the names just like that. I have tried to use Thread array() but it doesn't work.
I need to assign variables dynamically in a loop. In php you would use curly brackets but this doesn't work in vb.
Dim i As Integer
For i = 1 To 12
lblMonth{i}.text = 'whatever
Next
Anyone know how I can escape the the i variable so it becomes part of the string that precededs it?
This seems basic but here's my problem. I am trying to build my connect string as a public variable that will connect to either an express version of SQL Server or a non-express version. The app.config defines it as being express or not and is modified to the user's choosing when it is deployed using the a firstRun routine.
The problem is that even though I'm modifying the value of the variable SQLexpress when the app is initiated which in turn should modify the value of the variable g_strConnectionString it doesn't. The value of g_strConnectionString will always take on the initial value of SQLexpress. I know I can define 2 separate variables for the connection string but I'd prefer not to have to change all of the references throughout each of the various programs in this system as they all have the same issue.
So in the following load event I've traced it and when it sets globals.SQLexpress = "", I then look at the value of g_strConnectionString and it still contains "SQLEXPRESS". It seems I need to somehow force vb to refresh this variable after it's been changed.
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I have a script where I make separate routines with identical code
Example:
sub AddToA {
ATotal += 1
}
sub AddToB {
BTotal += 1
[Code]...
I have an application that I'm writing and I'm trying to declare two variables from my sql server, store the values and pass them to my forms.[code]...
View 5 RepliesLast year (2010) I came across a FANTASTIC command that allowed me to take a string of variables with a common delimiter and break it all back out into separate variables (possibly an array) with one statement.
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As long as the delimiter was a unique specifiable character, this one-statement command could break it out into elements. my memory and point me in the right direction.
I have code, shown below, that works all except for 1 thing: The variables being passed byRef get passed, but once modified in the else section of the "if me.invokerequired" code of RecordData, the variables are never updated in the calling function. To reiterate, the calling function does not receive the updated data that is in the variables custid and amt.When debugging, I see the data change in the else section of "if me.invokerequired", but once it returns from the callback the data is missing.[code]
View 15 RepliesI define some global variables of a class as follows:
Private Class MyClass
Private var1 as Decimal
Private list1 as List(Of string)[code].....
But I found that after this form is closed, all above variables, var1, list1, list2 still exist in memory. I thought they should be collected by gc since the form is already disposed as I confirmed.
Add: I have monitored half an hour after the form is closed. But these variables are not collected by gc. I have an automatic update procedure on the form which uses above variables.Since the above variables still hold values, the automatic update procedure is always called which causes exception. (One quick fix is to check if form.isDisposed in update procedure. But I do not think this is elegeant. Besides, these variables occupy memory.)
I have this code.
Code:
Public Class Form1
Dim NPB As Button
Dim x As Integer
[code]....
As you can see, when I open a program from my menu, a new button will be created with text similar to this, "C:Program ". The button it self will not do anything. How can I create the method at the same time the button it is for is created? Also how can I change the text do that it gives me, for example, CCleaner.exe instead of the whole target path?
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 RepliesQuestion 1: What is the difference between "Background Worker" and "Worker Pool" as indicated within the MSDN samples provided.
Question 2: I noticed while using, AddressOf _Function_, variables cannot be passed; what would be an efficient solution to this?
Question 3: While using multithreading is it required to invoke before setting variables, or only form properties?
Question 4: While using System.Net.Sockets is it safe/efficient to use Application.DoEvents while waiting for new data; or would be using a Do While loop be fine without DoEvents since the action would be multithreaded? Note: there can be up to 2000-3000 sockets in use at a time.
I'm new in .NET programming.I have a class Form1 that includes Button1_Click event.Button1_Click creates a multiple Text Boxies at run time)Here is the class:
Public Class Form1
Dim shiftDown As Integer
Dim counter As Integer
[code].....
