Storing Multiple Arrays Into A List
May 11, 2011
The scenario is:
1)A large 2 dimensional array (400,20)
2)The program needs to access particular chunks(for example (0,20) to (50,20)
3)The program will open multiple files and process each into it's own 2D array (400,20)
What I have right now is code capable of creating the array, but no way to store the array so that I can open a new file and process that data into another large array. Someone mentioned the generics List(of T) might be a good way to store each new array as you could use the Add function. I have done some research on the List(of T) class but I'm not totally convinced that is the way to go. I'm just looking for some direction as I've just started on .net this year.
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Jan 9, 2011
i am using vb 2010 i was working with images.....i extract a pixel from the image using getpixel()...but wen i assign it to an array of colors i am getting a run-time error.
"Object reference not set to an instance of an object."
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Apr 22, 2011
storing data into an array. I understand how to place information in one record eg in index 0, but how do i place data into several records(indexes).
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Dec 7, 2011
I'm still doing upgrades on my program that i'm creating and i've run into a bump again. I'm currently using a multi-dimension array to store a name, email, password, email provider, and user name. These 5 values are stored, corresponding with the latter, meaning the array is build as: name 1....n user name 1....n user email 1....n user email provider 1....n password 1....n So my question is, how can i store this in My.Settings? To be clearer, i'll use code: My.Settings.Name = name My.Settings.UserName = userName etc..... My current set up for a first run is like so... My.Settings.Password = adminInfo(2, 0) My.Settings.UserName = admingInfo(1, 0) etc.
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Feb 5, 2009
i have declared an array which i want to populate with names, as they are entered into an input box.It does not seem to work i have tried many other methods with the array but to no success.
Dim namearray() As String
Dim i As Integer
name = InputBox("Enter the candidates name:", "candidatename", "", 500, 500)
name = namearray(i)
i = i + 1
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Feb 6, 2012
I am trying to store 8 separate pieces of information in a text file (like a database) [but not a SQL database], consisting of integers and strings. How would I use an array to do this? Will an array collect data from text boxes (I also want to display the 8 pieces of information in separate boxes). also how would I save the text file so I can open it again or open a different text file (database?), from within the program?
EDIT: I see I need to use readline and writeline to read/write from a text file but how would I find specific data to show in my boxes?
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Nov 22, 2009
SI have a form and on submit I need the following variables stored in array.
Dim OrderName, OrderNumber, OrderSize, OrderQuantity, OrderAddOn, OrderEachPrice, OrderTotal As String
So pretty much its an order a customer will be making and every time a new order is placed, a new array will be made.
Example:
OrderName = TextBox1.Text was Sean
OrderNumber = TextBox2.Text was 123456
OrderSize = TextBox3.Text was Large
OrderQuantity = TextBox4.Text was 2
OrderAddOn = TextBox5.Text was Pocket
OrderEachPrice = TextBox6.Text was 10
OrderTotal = TextBox7.Text was 20.00
On submit a new array would be created and would be something like this:
Dim ArrayName(,) As String = {{"Sean", "123456", "Large", "2", "Pocket", "10", "20.00"}}
BUT a new array has to be created each time the submit is clicked.
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Sep 3, 2009
My xml files were looking a bit clumsy when i read them, what i have done now is to save them in the xml in this format:
vb.net <field>{value1|its partner value2}</field>
i noticed {|} this is the format that vb.net uses for arrays, i was wondering if that's an ok way to store things, on retrieval once i get the node value, what would be the best way to break up the {value1|it's partner value2} variables to use, explode the | and get parts (0) and (1)?
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Jun 13, 2011
I'm trying to read data from a text file with multiple records and fields separated by tabs to store into arrays, which I later want to output into a textbox on the form. The problem is that with the code I've written, when I debug it it exits the sub procedure when it enters the first loop where the parser is reading the text file. There are no error messages, it just exits? I'm not even sure if what I've written is possible. Here's what I've written so far:
[Code]...
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May 28, 2009
In my application i am having lot of functions and now i want them to be public function i mean that where and what is the best method of keeping this function in one file or control where i can call them from any where in the VB application , i am using visual studio 2005?
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Mar 23, 2010
I am wondering the best way to store an object in memory that is used in a lot of classes throughout an application. We have multiple databases, 1 per customer. We also have a master table and each row is detailed information about the databases such as database name, server IP it's located and a few config settings.
I have an application that loops through those multiple databases and runs some updates on them. The settings I mentioned above are updated each loop iteration into memory. The application then runs through series of processes that include multiple classes using this data. The data never changes during the processes, only during the loop iteration.
The variables are related to a customer, so I have them stored in a customer class. I suppose I could make all of the members shared or should I use a singleton for the customer class? I've never actually used a singleton, only read they are good in this type of situation. Are there better solutions to this type of scenario? Also, I could have plans for this application to be multithreaded later.
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Aug 22, 2010
I'm trying to store three images from a form (PictureBox's) into a SQL Database (MSSQL2008) The below does what I want but is clearly inefficient. Any pointers on what to change to improve this?
Private Sub SaveImages()
Dim ConStr As String = "Data Source=SERVERSQL2008;Initial Catalog=NorthPole;Integrated Security=True"
[Code].....
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Feb 25, 2012
My problem is storing multiple string in the my settings to clarify more on this ill try explaine as best as i can,
'I set my value like so
Dim strSettings As New My.MySettings
'On the form load i use this
Dim itemz As New ListViewItem
[Code]....
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Mar 4, 2012
How can i use .filenames of a openfiledialog with a string?
[Code]....
but i get error: Error 1 Value of type '1-dimensional array of String' cannot be converted to 'String'.
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Jun 10, 2011
I'm storing images in a List Of Image. When I want to clear/remove all the images it contains should I dispose & set each item to nothing before using .Clear? Or can you just call .Clear? I'm doing it like this for now...
' remove all images in list of image named "images".
For i As Integer = 0 to images.Count - 1
images(i).Dispose()
images(i) = Nothing
Next
images.Clear()
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Jul 11, 2011
I have a VB2010 application that must run as multiple instances on the same PC (it is a controlling/monitoring program of several devices, each instance of the program control one device)
Of course, the same application must save its own setting in different place, one for each device. For example, if I start the application for the device 3, I have to save the setting in a place marked as "3", in this way, when I start the application for device 4 it will load the settings for device 4 and not 3.
Of course all labels and similar stuffs must refer the starting device: i.e. the mdi caption must report "device 4", and so on...
In vb6 I created a shortcut with a command line and made my application accepting command line parameters.
In this way I could start the application passing the device number too. For example "myapp.exe 3" start my application for the device 3.
I stored all settings in several INI file, each one for a device: setting1.ini, setting2.ini, setting3.ini, ....
I was wondering if in vb2010 would be a better way to do that.
1. How could I start multiple instances?
2. How could I store the settings?
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Jun 12, 2011
I have a form displayed where a user can can select a 'function' from a list box. That 'function' has a corresponding ID number which I need to be able to take and use later in the code.The List of functions is preset (about 150+ them and the IDs are already assigned (so I can't just use the index).So if the user selects "Function A", I need the code to set a variable to, for example "42" (or whatever that Funtion's ID is).
I was going to do this using listbox.item and listbox.itemData, but I'm using VB.Net in VS2008 and I understand that function is no longer present (to add ItemData at design time).Here's where it gets complicated. When the form loads it looks at the variable containing the FunctionID and if there is one present, I want it to populate the co-ordinating FunctionName. I can do that if I know the index number, but I don't know how to look at the FunctionID and return it's index (all FunctionIDs are unique).
A) store the info, either in the Listbox using ItemData, in an array (but I'd prefer to do it at design time), or some other way you might suggest.
B) cross-reference the ID and display the name in the listbox when the form loads.
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Sep 19, 2011
What I'm trying to accomplish is first of all, adding items in a list box, but while doing so, store data into that item so when the user clicks on it, the data will be brought up into the correct text boxes.
My idea on how this will all work out has to do with array lists. I'm thinking each time an item is added to the list box, an array list is generated containing all the data from the text boxes. The array list would be named as the text of the list box item.
So then when the user clicks on one of the items, it can find that array list easily because of the selected index, and then update the text boxes with the data.
Is the way I'm thinking of possible? If not, or if there is an easier what, what would that be?
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Dec 7, 2010
In .net, it's possible to use generics so that a function can accept arguments which support one or more interfaces and derive from a base type, even if there does not exist any single type from which all valid argument types derive. For example, one could say: Sub Foo(Of T As {IInterface1, IInterface2, SomeBaseType})(Param as T) And be allowed to pass any derivative of SomeBaseType which implements both IInterface1 and IInterface2. This will work even if SomeBaseType does not support Interface1 and Interface2, and classes which do implement those interfaces don't share any common ancestor that also implements them. This can be very convenient if one won't need to keep the parameter anywhere after the function has exited. Unfortunately, I can't figure out a way to persist the passed-in parameter in such a way that it can later be passed to a similar function, except perhaps by using Reflection. Is there any nice way of doing that?
The closest I've been able to come up with is to define an interface INest (perhaps not the best name-- thus:
Interface INest(Of Out T)
Function Nest() As T
End Interface
And for any interface that will be used in combination with others or with base-class "constraint", define a generic version as illustrated below:
Interface IFun1
' Any members of the interface go here, e.g. ...'
Sub DoFun1()
[CODE]...
A class which will support multiple interfaces should declare itself as implementing the generic ones, with itself as the type argument.
Class test123a
Inherits sampleBase
Implements IFun1(Of test123a), IFun2(Of test123a), IFun3(Of test123a)
End Class
If that is done, one can define a function argument or class variable that supports multiple constraints thusly: Dim SomeField as IFun1(Of IFun2(Of IFun3(Of sampleBase)))
And then assign to it any class derived from sampleBase, which implements those interfaces. SomeField will implement IFun1; SomeField.Nest will implement IFun2; SomeField.Nest.Nest will implement IFun3. Note that there's no requirement that IFun1, IFun2, IFun3, or sampleBase share any common derivation other than the generic interfaces inheriting from INest(Of T). Note also that, no matter how many INest-derived interfaces a class implements, it only needs to define one implementation of INest(Of T).Nest. Not exactly beautiful, but there are two nice things about it: (1) any concrete class which in fact implements the necessary interfaces can be assigned directly to a field declared as above, without a typecast; (2) while fields which chain the types in a different order are not assignment compatible, they may be typecast to each other. Is there any better way to store something in such a way that it's "known" to support multiple interfaces and derive from a certain base type? Given that one can write such code in a type-safe manner, it would seem like the .net 2.0 CLR could probably support such a thing quite nicely if compilers offered a little assistance.
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Jan 24, 2012
I was looking through some legacy code we have and I noticed something that struck me as particularly odd.Say we have the concrete class TestClass. TestClass implements the interface ITestClass.What sort of behavior should I expect in the following case, then? (I didn't realize this was even possible)
Dim testClass as TestClass = Nothing
Try
testClass = New ITestClass
[code].....
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Oct 24, 2009
In a resource string, not one that you declare in the code, but rather in the resources itself, how do I store multiple pieces of data in it?
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May 7, 2009
I'm new to this, so sorry if my question has been asked before. I have searched but have not been able to find, or perhaps recognise, an answer. I am using visual studio 2008 and creating an app in vb.net.
I have 4 arrays named:- account1 account2 account3 account4. They all have 4 elements.I want to assign values to the elements in the arrays in an efficient manner. I thought two for next loops would do it. [code]....
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Apr 29, 2010
trying to save users names and passwords from input boxes and save it as arrays in text file that in future multiple users will log in with their names and passwords
have this code so far but doesnt realy save the user info to file, dont even create file.
Imports System.IO
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
[Code].....
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Mar 13, 2009
I want to go to a class.vb file that has a function from an aspx page and I want to return mutiple arrays. Is that possible? If so, how would I call it from the aspx page and how would I return it?
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Jan 8, 2009
I'm trying to find out a way to search multiple arrays for a specific value. I looked through here, yahoo, google and msdn and couldn't find anything specific to what I'm looking for. Don't have any sample code as I'm not quite sure where to start.
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Apr 28, 2011
how to take a text file that was provided for my homework assignment, and put the information within it into 3 different arrays.[code]
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Jun 10, 2011
i'm having issues where I can't figure out how to take a text file that was provided for my homework assignment, and put the information within it into 3 different arrays.The .txt file looks like so:tc.Amanda/Ashley have to be in the same array as well as 4/2, 166/20.This is what I've come up with for the snippet of code, and so far, it hasn't really been working right.
Dim namearray(MaxItems), rankarray1990(MaxItems), rankarray2009(MaxItems) As String
Dim Numitems As Integer
Dim sr As System.IO.StreamReader
[code].....
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Nov 10, 2010
I have the following code... in an MDI application. [code] Various lines of code which put data into the Myinstance and then save the instance into the ArrayList.I have buttons which run procedures and functions in the formchild and also in the Class1. I need it so you can jump between formchild instances, and when you do so and click a button on that form, it will run the Class1 code but using the data in the arraylist and myinstance that was set previously by the selected formchild. Then if you switch to another child it uses data from this form. Can this be done by declaring the arraylist with more dimensions and then refer to the records with the index of the selected form instance, e.g.Selected Child is index(3)
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Nov 6, 2010
I have created an MDIparent form and a MDIchild. There is a button on the parent which makes multiple 'clones' of the child form, each time its clicked.I also want (maybe with a module) a set of variables, and array of a structure but these are available to each copy of the child, but each copy's variables, arraylist etc contain its own data?Therefore if you select child1 the variables and array will have different data to child2, child3...etc...
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Apr 9, 2010
if its possible to split an array into multiple smaller arrays?
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