I'm stuck on a problem that I haven't been able solve. I'm making a visual basic program that communicates with an SQL-database. The problem emerged when I tried to retrieve data from the database with the help of SqlDataReader and save data from every row to a list (Customer) with the help of Add-method. It turned out that eventually the list had correct number of objects, but the information was the very same in each object of the list.
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.
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")
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.
I want to retrieve an object by using a string representation of the objects name. For example lets say i want to change the font of 3 labels on a form programatically. Instead of changing the font property for each individual label like so:
I'm using a mysql as my backend database and i'm using the mysqldata adapter for binding the data, i have my data in the database, but the problem is i don't know how to retrieve it, for example when i want to add a record, before i add that record, i want to retrieve the data in my database to trap that the record i'm adding is an existing record
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 need to summarize data from an arraylist in vb. For example, I have a list of dates with different times. I want to summarize the dates and be able to display the times when I click on each date.I am new to vb, and I am struggling with this. I am able to read the file(ofd) with this info but I can't get it summarize, instead I am showing the date multiple times.
How can I read data from a .csv file I have opened into a variable for later use (i.e. plotting with zedgraph)? My csv file contains 100+ columns and 12000+ rows of data, with each column a different variable.
I've searched around a ton on this subject, and combined many methods I found on the net to my project but none actually do what I am required to do.
I have an arraylist (arrFirstArry) which I use to populate another arraylist (arrNoDuplicates) preventing any duplicates from being added. This works fine. What I would also like my code to do is prevent adding any partial values which may exist from being added. i.e. my array is like this
I have two structures Public Structure myResearchData
Public batchName As String Public arraylistRData As ArrayList End Structure Public Structure myResearchSubData Public researchDescription As String
[Code]...
Cleared MyResearchData.arraylistRData for new data to be put in but it also clears the arraylist inside MyResearchDataAList and didn't old the contents of the arraylist
What I need to do is read an ArrayList in My.Settings and add another ArrayList to it. The first think I'm trying to do is load My.Settings.Records into myArrayList. I'm not quite sure on the proper way to do this. I've tried things such as Dim myArrayList As ArrayList = My.Settings.Records, I'm not sure if I need New and I'm not sure if I need .Clone or .CopyTo.
Then I have another ArrayList myArrayList2. To get this into myArrayList I've done: [Code] Then to save it back to My.Settings I've done. My.Settings.Records = myArrayList. The problem is I keep on getting Object reference not set to an instance of an object error on the AddRange line. My.Settings.Records is definitely an ArrayList and it will sometimes = Nothing. The objects will only ever be strings.
I got a weird problem here like I got a site that users can post comments on a friend profile page.Everytime a user post a comment my application sends e-mail to that page owner, you know to inform for a new posted comment on his/her profile page.The problem is I want to stop the application from sending email if that user has just recently posted a comment say like 5 hours ago/earlier.Here is the function I use that would try to check it:
I have MSaccess database.I have 2 tables 1) CUSTOMER TABLE=----CUSTOMER ID-Primary --AUTO NUMBER2) ORDER TABLE =----(CUSTOMER ID--Foreign KEY) Now From the front end using VB.net I have an page in which if i enter Customer details and press button add .I have to INSERT into values into CUSTOMER TABLE and I Also at the same time INSERT into ORDER TABLE with this CUSTOMER ID which i generated now.How is it possibl