Arraylist Of Objects, Listbox1_SelectedIndexChanged, And Linking Values?
Nov 6, 2010
I'm completely new to VB.NET and this is likely a few steps over my head, but have managed to get myself this far with just Google.I'm reading an XML file and creating an arraylist of classes for the values in there, as seen:
Public Class yresults
'Dim xdate As XmlNodeList = xDoc.GetElementsByTagName("Date")
'Dim link As XmlNodeList = xDoc.GetElementsByTagName("Link")
I use serializer classes for storing data and each class can hold an array of objects for the same class which is a key feature of the class. I declare this array as so:
myClassObjects(1000) as myClass
My question is- can I declare the array as an arraylist so I can sort and count objects in the array(list) quicker and easier and are there any drawbacks to taking this approach?
1. how do you edit objects in an ArrayList? 2. the code below works ok but is it ok to obtain a reference to an object from an ArrayList and then edit the object?
Public Class Form1 Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
I have an ArrayList that is populated with Objects. These Objects raise events at certain times. How can I capture these events from the ArrayList? i.e. I want something like this: Public Sub MyRaisedEvent(ByVal obj as MyObject) Handles MyArrayList.MyEvent End Sub
when i do a count it display a list of 25 items in the folderlist.Now i have a main class when i tried to use the following method
Dim MainClass as New ClassB
Console.writeline(MainClass.FolderList.count()) the value reflects as 0 items meaning is empty.i need to retrieve the arraylist from Class B using the MainClass to retrieve those items inside the arraylist.
How can I sort an ArrayList of custom objects by public member? Example,If I have a list of article objects, and I'd like to sort the list by the rating member after I've filled the ArrayList
Public Class Article Public bulletin As String Public rating As Integer[code].....
Now I'd like to sort uniqueArticles by rating and print articles by rating order.How do I do perform that sort?
I have a group of objects stored in an arraylist. These custom type objects have a number of properties from their underlying class . I want to use one of the properties to sort the array. I cannot determine which Array.Sort method to use.
I want to sort based on an integer property. Virtually every example I can find involves sorting strings.
So, assume the Objects have the following properties.
Obj.name as string Obj.ID as integer Obj.Alive as boolean
The objects are kept in an arraylist called FriendsOfMine.
I want to be able to order the list by Obj.ID, both ascending and descending in value.
I have a class called Tree, it has an arraylist called alTreeNodes. alTreeNodes is an arraylist of TreeNode class. Since I am using ISerializable Interface, I have to provide a specific constructor. I know how to write it for string parameters such as name_value, but how should i do with arraylist of object then? See "???" in the code blog before.
Protected Sub New(ByVal info As SerializationInfo, _ ByVal context As StreamingContext) If info Is Nothing Then
After going through some tutorials I set out to work on my own game. Right now it's simple, I have a ship that moves left, right and shoots. I also have Asteroids that fly at the ship.
The problem is that I have 3 asteroids in an array, and they all act the same... I would like random speeds and directions.
I'm writing a tabbed web browser for someone who is learning VB.NET, and I have got to the point where I can add/remove browser controls into tab pages, controlled by one set of buttons on the main form, but I can't handle events from the WebBrowser objects.I have tried this but it says that 'DocumentTitleChanged' isnt an event of 'Control'...
Dim browser As New ArrayList browser.Add(New WebBrowser) browser(0).parent = TabControl1.SelectedTab browser(0).dock = DockStyle.Fill AddHandler browser(0).DocumentTitleChanged, TitleChangedHandler()
I want to update the tab title with the web page title when it changes. I started using a timer to update the tabs but there must be a way to add an event handler here.
Public Class BasicInformation Public maleFirstNames As New ArrayList Public maleFirstNames.Add("John") Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
I want to declare a set of arraylists and the base values so that they are available throughout the entire program. When I set the declaration for the array list as public and attempt to add a value to the array the add.("john")is underlined in blue and it says end of statement is expected.
I am trying to add values from Arraylist to particular column of grid view. As: If (Arr_NewContacts.Count > 0) Then dgvStayout.Rows.Clear() ' **GETTING ERROR HERE** dgvStayout.Rows.Insert(0, (Arr_NewContacts.Count - 1)) For i As Integer = 0 To Arr_NewContacts.Count - 1 dgvStayout.Rows(i).Cells("Name").Value = Arr_NewContacts(i).ToString [Code] ...... Datagrid property like AllowUserToAddRows and AllowUserToDeleteRows is already set to true.I am using above code on lost focus event of one of text box.
Actually values are not stored in that array list permanently. its storing temporarily and then destroying. i want to store that values in that arraylist permanently.
What I am doing is iterating through all the groups that belong to the top group (Generic reports). Then I take advantage of the GroupPrincipal.GetMembers(True) which will recurse through a given group name. I test to see if the user exits under that group and if true I put the group name in an arraylist.
I use the for each principal in GroupPrincipal.GetMembers to loop through each returned user to see if they exist.
Is there a way to put all the returned users Principal.Name from a given group in GroupPrincipal.GetMembers into an ArrayList? This would allow me to to use Arraylist1.IndexOf to search for user. Which would be much faster then iterating through a returned list using the for each construct.
Sub RetAllMbrs(strUser As String) Dim oPC As PrincipalContext = GetPrincipalContext() '<- this is function somewhere else in the code
I am having a problem with objects and arrays of objects. Basically obj_stored holds how many objects I have stored in my text file, in this case t shirts. line(y) is an array that holds each line that has been read from the text file. I then use this to assign values to my array objects properties. For example I know the first line is the color of the first t shirt, second size, third price etc. Then I know the next line will be the color of a new t shirt. There are 6 t shirts in the file.
Dim t_shirt(5) As Clothing.t_shirt Dim t_shirt_purchased As New Clothing.t_shirt For x = 0 To obj_stored t_shirt(x) = Clothing t_shirt(x).color = line(y) y = y + 1 t_shirt(x).size = line(y) y = y + 1 t_shirt(x).price = line(y) y = y + 1 Next MsgBox (t_shirt(4).size)
My problem is it seems to be resetting these values after it has finished. Im creating the object each time and assigning values to it's properties but when it's finished it all resets and says 'Object reference not set to an instance of an object'. I'm new to OOP and was wondering what sort of approach i would take to doing this, if the one i am taking is wrong.
So I am aiming to: Read everything in from the text file. Create new instances of the objects depending on how many t shirts are stored, (5 t shirts = 5 objects) Assign the values to my objects properties.
I'm new in this forum. I am also quite a rookie programming in VB2008. In fact I'm not even a professional programmer. The situation is as follows.
I was hired by a company to do an Industrial Engineering job, but after some time, I realized that my job was also to design a database manager in VB2008 for the train wheel stock. So I am terribly lost. My problem here is that I dont know how to compare values and assign the biggest with the biggest, the smallest with the smallest etc. So I want to create a table and auto-arrange the values. An example of what I want to do in a macro of Excel is[code]...
I have used XML serialization to persist objects in my application but I am now interested in using null- able Data types for properties. Will I still be able to serialize?
Im doing the same thing as him but in vb express 2008 what i have is a checklist box of 10 toppings, all of which can be selected, (no max or min) to put on a pizza, and i have 3 radio buttons grouped together for pizza size (S, M, L) i cant figure out how to give them vaules in which(for sake of demonstration) s=$5 m=$7 l=$9 and each topping is $0.25 then make them add up to an order total in a msg box or something like that
I coded a class that scans an object and maps data from a data table into each one of the corresponding properties, it works very well, however I am not able to set the property of one of the child (coplex objects)
Public Class CntrConfHdr Private m_CntrConfHdrID As Double Private m_HeaderCode As String
[Code]...
I want to set the value for the child object TypeCurrency.TypeCurrencyID thus I set the value of the variable sTargetPropertyName to TypeCurrency.TypeCurrencyID but the application willnot work stating that the property can not be found.
I am having so trouble with the ToUpper() procedure with strings. I am using LINQ to find unique values in a list of objects. In that whole process I set the values to compare to all lowercase in order to get a proper list. My goal is to populate a dropdown list with the values. I'm attempting to set the first letter of of the string to uppercase and keep the rest lowercase however the toUpper() procedure is not working?
Private Function FixCase(ByVal strIn) As String Dim strOutput As String Dim intStringLength As Integer = strIn.Length - 1 strOutput = strIn.Substring(0, 1)