Difference Between A Pointer Or A Variable In The Contect Of List Elements?
Apr 25, 2009
Do List's hold the instances of a variable element or just the pointer to the the variable element? My application uses a list of elements, which can be re-ordered at any time, but I need to maintain another list of pointers to those elements, so that the element pointers can be used to access any element irrespective of their order in the main list? the difference between a pointer or a variable in the contect of list elements?
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Aug 31, 2010
What I want to do is either trivial, or likely impossible in the .NET framework.
I have a number of forms, with various pictureboxes, labels, etc. in each. Same names for the same items on each form. Only one form is visible at a time. What I need is some way to assign to a variable in the code which form is currently in use, such that I can reference the control on that form in a single statement.
That is, I have set up (already) references to the individual forms (call them frmForm1, frmForm2, etc.). So I can write to a textbox as:
frmForm1.textbox1.text="Hi there."
frmForm2.textbox1.text="Hello world."
What I need to be able to do is something like:
currentform = frmForm2
currentform.textbox1.text="Display on visible box"
Is such a thing even possible? Obviously, the way .Net normally wants to work is to verify everything at compile, and there is (of course) no way for it to know if whatever "currentform" points to even has a "textbox1" control.
save me a LOT of long-winded IF-THEN-ELSE to see which form is currently displayed for each and every time I want to display something. [FWIW, I *could* right everything out to every form, but I feel that would waste to much CPU time.]
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Oct 26, 2011
This is probably a really basic question - but I have a list of items (custom objects) being passed from one winform (.net 3.5) to another. I want to create a local list to store changes that only get persisted if the user clicks save. Currently if the user clicks cancel - the changes are still applied in the first form because I assume the objects are reference type.I have the save working as it calls a service layer to do the save and then refreshes the other form - but not the cancel.
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Oct 1, 2010
I have two pictureboxes in my form. When I hover my mouse over Picturebox1, I would like to make picturebox2 visible. Here is what I could not manage: This second picturebox should magnify the photo inside Picturebox1 according to the place of mouse. For an instance, if the mouse pointer is on the upperleft part of the Picturebox1, Picturebox2 should show the magnified status of this upperleft part.
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Mar 5, 2012
I long variable in vb.net which contains the following information,
Dim g As String = "$C:Program FilesCavaj Java Decompilercavaj.exe$C:UsersYoosufAppDataLocalGoogleChromeApplicationchrome.exe$C:Program FilesDVD Makerdvdmaker.exe$C:Program FilesAdobeAdobe Photoshop CS2ImageReady.exe$C:Program FilesJavajre6injavaws.exe$"
The $ symbol is used as a delimiter to separate each item from the other. I need to add the exe file name at the end of each path to a listbox. However the initial process of retrieving the variable to individual array elements is not working properly.
Dim strArr() As String = g.Split("$") 'This variable is empty
For count = 0 To strArr.Length - 1
Dim arr As String = strArr(count).Split("")
[code]....
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Mar 11, 2012
I want to copy the elements from one list to another.
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Apr 11, 2011
I'm Having trouble getting a list of elements to load. The data is defined like this:
Public Class NavEquipmentMgr
Shared M_ps_NavQuit As Boolean
Shared M_ps_No_Nav_Equip As Boolean
[Code].....
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Apr 7, 2011
I got a list of objects. Each object has a property called Z (integer).There will come a point during run-time I will want to re-arrange such objects in my list depending on their Z property. The objects with lower Z go first in the list, and the ones with higher will go last.I have thought of a couple things, like making a new List, then loop through each object in the original list as many times as the amount of objects such list has (so if it has 10 objects, I would loop 100 times), and each iteration will check the Z values. When a cycle is done (for every 10 iterations), I will remove the object with the lowest Z number in cycle and add it to the new List. And so on until the 100 iterations are done.
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Feb 6, 2010
I have a List of a custom class (barData) that I need to remove elements form based on a date.
The bardata class holds data of stock price information.[cod]e...
Is there a way to do it without looping through each bar as I may have 2000 plus bars for each stock and may have 2000+ plus stocks to look at. It can be done by looping but it is slow.
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Jul 15, 2010
I have an open source project I converted to vb.net. I solved all the errors, except for one. This is the C# line
[Code]....
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Jul 13, 2009
I would like a function generate all of the k-combinations of elements from a List of n elements. Note that I am looking for combinations, not permutations, and that we need a solution for varying k (i.e., hard-coding the loops is a no-no).
I am looking for a solution that is a) elegant, and b) can be coded in VB10/.Net 4.0.
This means a) solutions requiring LINQ are ok, b) those using the C# "yield" command are not.
The order of the combinations is not important (i.e., lexicographical, Gray-code, what-have-you) and elegance is favored over performance, if the two are in conflict.
(The OCaml and C# solutions here would be perfect, if they could be coded in VB10.)
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Oct 31, 2010
I am creating a dynamic clone method to be used in my custom classes. I want the clone function to be completely generic, so I do not have to make any changes when I add new properties to the class. I am having an issue with regards to making a deep copy a property that is a List. sample code that will enable me to identify with reflection that a property of my class is a List, and then more importantly the code to loop through the the List elements and copy of each of them. I have been able to identify a property as a List by using the NameSpace of the property type, but I'm not a big fan of that method. Either way, I have yet been able to dynamically loop and deep copy the elements of the property that's a List using reflection.
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Jan 17, 2012
I'm making a bot to auto-reply to my PMs on a website, and I'd like to get all of the HTML elements with a class name 'InboxRow'. I can get the HTML element one at time, but the problem is that these will be dynamic, so the id and amt. of them will always change, so I want to put them in an array, where I can call each one up and perform the rest of my code for it. I just can't seem to be able to figure out how to find all the HTML elements with the class name and put them in an array, and I can't seem to find any tutorials online
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Mar 9, 2010
Is there any difference between the 2 methods below for calculating c ... specifically boxing/unboxing issues?
Dim a As Integer? = 10
Dim b As Integer? = Nothing
Dim c As Integer
' Method 1
[code]....
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Nov 4, 2010
Will the elements in myList always be visited in the same order with a For Each loop (assuming I don't alter the list)?
Dim myList As New List(Of MyElement)
....
For Each myElem As MyElement In myList
' yadda yadda yadda
Next
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Mar 25, 2012
Is there a succint way in vb.net to create an array or similar of each of the properties in a list?
E.g. If I have a list of 'a' and each 'a' has a property 'b', I want to create an array which contains all the 'b's, in the same index positions as the original list.
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Aug 19, 2011
I have a user defined structure in a list that I am trying to change the value for in an individual element within the list of structures. Accessing the element is not a problem. However, the compiler complains
"Expression is a value and therefore cannot be the target of the assignment"when I try to update the value.For example:
Public Structure Person
Dim first as String
Dim last as String
Dim age as Integer
[code]....
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Feb 27, 2009
I need to set up a list consisting of arrays of two elements. Simple, right?
Like: (code snippet):
Dim strDataPoint(1) As String '2-element array
Dim lBiasCurve As New List(Of strDataPoint) 'list of 2-element arrays
Dim lPwrCurve As New List(Of strDataPoint) 'another list of 2-element arrays
But this gives me an error msg on 2nd and 3rd line: type strDataPoint is not defined....
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Sep 21, 2010
I'm trying to copy the elements from a List(Of Frequency) where Frequency is a custom class I have made. Everything in the other places seems alright but the problem seems to be with the copying, where it still references the original table, so changing the values of one changes the original. I've tried the List.CopyTo() method and tried converting to and array with List.ToArray and then using Array.Copy but it seems they always change the original. I've also tried a for loop and create and New instance of the classes but that doesn't work either. What I'm using it for is to pass the List(Of Frequency) to a new Task to do multitasking(), if anyone can think of a better method to pass a List(Of Frequency), or an array to to a task and have it not change the original.
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Mar 8, 2010
I have got an xml document which looks something like this.
<Root>
<Info>
</Info>
<Info>
[Code]...
How can i write a linqToXML query so that it returns me an IEnumerable containing each child element, in this case all five child elements of , so that i could iterate over them. The order of child elements is not definite, neither is number of times the may appear.
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Jul 6, 2011
I have to get all the Entity Source,Entity Target,Property Source and Property Target values in list respectively.[code]...
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May 17, 2011
I have a string with xml data.Dim appManifest As String = New System.IO.StreamReader(Application.GetResourceStream(New System.Windows.Resources.StreamResourceInfo(e.Result, Nothing), New Uri("AppManifest.xaml", UriKind.Relative)).Stream).ReadToEnd()
[Code]...
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Feb 2, 2011
I use the removeRange function to remove a couple elements from a list, but the Count of the list seems to be intact, so I assume it didn't work the way I expected it too.... so, how do you remove elements? I mean, reduce the list's Count value ultimately.
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Aug 4, 2009
I am using VB 2008 and wonder if there is a way to draw lines between the data elements in two listviews to bind the elements together?
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Jul 18, 2011
I have the following "contact" data (exampled below) stored in an xml file.I've created a frmContacts windows form and placed a list box control inside it.I'm new to the list box but plan to have the users manage the list by letting them add, delete, and pick from it. For searching there should also be a sort function/button (by last name then first name).If the user deletes from the list the corresponding data in the file will be deleted.If the user picks from or adds to the list, I'd like to find the best way to populate the corresponding data elements on another form (i.e., in their respective text boxes). This will include the ability to edit/save from this other form too.
<?xml version="1.0" encoding="utf-8"?>
<Rows>
<Row>[code]......
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Apr 13, 2012
What is the difference between a queue(of t) and list(of t)? I've been working a lot with list(of t), but up until recently I haven't even heard of queue(of t). I know that they are both general list.
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Apr 4, 2011
How would I create a list of elements in VB.NET, save it to a .dat file, and make Ruby re-create such list (as an array) with such elements (they will be strings, booleans and integers)?
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Sep 10, 2010
I'm having a problem where I have elements such as Listboxes and Rich Text boxes that I want to set to size automatically in xaml according to the size of the window, but I only want it to resize to the size of the window and then put scrollbars if the content is any bigger than that.
Unfortunately, the only way I can get scroll bars to work is if I set a specific height of the listbox/rich text box (which does not work because I want it to automatically resize to the height of the grid that it is contained within, which is generally the height of the window (auto).
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Jul 27, 2010
I need to create a remoteable object with a method that sums up elements in an array list. How do i go about it?
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Dec 20, 2010
I know boxing and unboxing part in arraylist but question is if I define only string in arraylist then there is no question of boxing or unboxing. What will be the difference.
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