I'm trying to figure out a way to sort the entries of a listbox... but in a different way instead of the obvious one (sorted property). First of all, I need to explain how the items are populated at first:
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What is an elegant way to create and initialise instances of a class that has several readonly properties? Passing all values in a constructor would not be very convenient.
The purpose is that instances are immutable after initialisation. However if the constructor is not used for initialising all the property values, then how can the readonly properties be changed from another class?
I have an array of people stored in a custom structure array... how can i copy this array to a temp array so that the temp array has all the same values as the original custom array?
View 4 RepliesAm trying to copy contents of file temp.fxl to temp.seq. I want them to look exactly them. I don't want to copy the file though. I use the following code
Dim fs As New FileStream("c:\fxlate\output\temp.fxl", FileMode.Open, FileAccess.Read)
Dim s As New StreamReader(fs)
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With such simple code, the last line in temp.seq is truncated as attached and the size of the file is smaller than temp.fxl. See attached files. What do I need to do on the above code. Is VB.NET failing to write 1024 characters on one line.
I have created a Class, basically like this:
Public Class Person
Implements IEquatable(Of Person)
Public Sub New(ByVal Name As String, Optional ByVal Like As Boolean = True)
Me.Name = Name
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I have a List of FileInfo objects that I want to sort by creation date & file size. Is there a way to do that?
View 5 RepliesI have a .NET class, InstrumentConnector, that has an event, StatusChanged. I want to create several instances of this class (each class handles a separate file) and respond when the StatusChanged event is raised any instance. How would I do this in .NET? Do I want to create a List(Of InstrumentConnector) or a similar IEnumerable? How do I write the event handler to respond to a particular instance's StatusChanged event?
Here is the InstrumentConnector class and the module with the StatusChanged handler:
Public Class InstrumentConnector
Private _inProcessDir As String
Private _doneDir As String
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I have a list (i.e. Dim nList as new List(of className)). Each class has a property named zIndex (i.e. className.zIndex). Is it possible to sort the elements of the list by the zIndex variable in all of the elements of the list?
View 4 RepliesIs it possible to save into temp data a user made class? I have a class with many structures and each structure contains variables and im trying to add to my program a way to save the data of that class object with its structures and everything is that possible? I tried manually making some sort of save but its taking too long and proving way too hard for me. Is there a way to just convert it into some general object format and save the object? Is that possible can you just save undefined objects without having to create a format manually for that object?
View 6 RepliesI'm using the following code to sort a List(of Class) using LINQ. It works fine, but I'm wondering if there is a better way to do it. I'm basically taking one list, applying LINQ to it, then using the result to create a second list in the sorted order. Can I do this without creating a second list? Here is my sample
' KeyMatch is my Class Variable
' mMatchList is the Unsorted List
'
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I wrote a function that copies the properties of one class to another so make a copy of an object.So something like
MyObject myObject = myOtherObject.MyCustomCopy(myObject)
where myObject and myOtherObject are of the same type. I do it by bascually doing
myObject.prop1 = myOtherObject.prop1
[code]....
I am pretty sure in the past I used a .NET object that automaticaly did this, by reflection I guess, but can't remember it ... or an I imagining that such a method exists?
I'm a little out of my comfort zone here having programmed in VB6 quite a few years ago things have changed a lot since then.My issue is I have a class that I've built which works with no issues but I would like to be able to keep a 'handle' of some description on this class so I can also make adjustments to it's parameters when the user changes something. My problem is that I need to do this for an unknown quantity of these class instances.
In the VB.Net language how would I create an instance of this class that could be accessed by any Sub within the application and each instance created can be individually accessed by specifying some sort of identifier?
I'm trying to create a class for storing data on People with another class to store their Bank Transactions.Ideally, this all be hidden away and leave only simple statments, declarations and functions available to the programmer.[code]I know this is possible as these exist in the Listbox Class though can't figure out how it's done.
View 2 RepliesI am trying to understand classes in VB 2010. I am a bit confused with displaying information from a list into a listbox.When I run the following code, the word collection appears in my list box. How do I drill down into 'hostnames' to display the info I want.
Public Class computer
Private _HostName As String
Public Property HostName As String
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I have an application that receives data input from an automated set of devices. This data stream I have managed to capture & get it into a list box which I can sort based on the Device ID & the time that the response was received.There is a set time window for the devices to transmit their data into the application and during this each device is not limited to the number of responses it can send (ie :- Device 1 can send in 2 responses where Device 3 can send in 40 responses, etc).All of the responses are captured, listed & sorted within the listbox (this bit is working ).I now need to extract the last (ie:- latest) entry in the listbox for each Device ID & this is where I am stuck. I can retrieve the last item in the list but cant seem to extract the last item for each Device ID.The code that I am using for the Device response capture, etc is :-
*********Code Start
Private Sub btnPoll_Click(ByVal sender As System.Object, ByVal e As_ System.EventArgs) Handles btnPoll.Click
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Is there a way to validate ALL properties in a class at once? I have a class with various validations added to property "Getter" to validate user inputs. (The problem is that all my validations only invoke if a user input something to the field that bind to the property. Any fields that user simply bypass will not get validated). Ideally I want to loop through each property and validate in a "Save()" method.
View 8 RepliesI want to read a number of items from a file and then associate each of those items with a new button at run-time, so that when the user clicks one of the buttons I can display some information about that item.Can I use a LIST to manage these buttons and items? Can I create a new class and have each list item of that class, such as 'btnID', 'btnText', etc... ?
View 2 RepliesOk so my boss told me that I can't use DataSet's and dataadapter and such like this because it isnt good for scalability. So, I must change the way I have my 28,000 records binded to my form. The problem is, I'm only 3 months in with VB.NET and I don't know of any other way to accomplish what I need to do. I was reading somewhere that I can use a Class as my "Order" and I can bind the variables/properties to the form and with this, I can navigate through records while having controls on each important part of the "Order". Unfortunately, I don't know what I'm doing, this is as far as [code]Any guidance as to what I am to do from here in order to pull the data from my database and bind to the property, then to a text box/combo box, and a way that I can use my binding navigator to go through the many records.
View 13 RepliesI'm trying to elaberate on some basic examples of .Net programming in using VB. The basic example of creating a new instance of Form1 is:
Dim x as New Form1
x.Show
I've added some OptionButtons to set the StartPosition of the Next Instance of Form1 as well as some Labels that display the Top, Left, Width and Height properties when the new instance of Form1 is Shown.
This is the code I'm using.
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim x As New Form1
If Me.RadioButton1.Checked = True Then
x.Top = 0
x.Left = 0
[Code] ......
I have created a class for a Sports Facility. A facility has a Name, Status, Notes, etc as members of the class. This works well, I can create a new instance of an exisitng Sports Facility from the database, create a new instance, etc. All working well.What I am stuck on is accessing a list of Sports Facilities. I know I can create a new list by doing
Dim List As New List(Of Facility)
For Each fRow As DataRow In ds.Tables("Facilities").Rows
List.Add(New Facility(fRow.Item("FacilityID"))
Next
I'm getting System.NullReferenceException error when I try to add the employee info to the Employees list.
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Is there any way to add new properties to a control? For example, I'm using an "OvalShape" from Microsoft's Powerpacks, these are designated as "Cells". I would like to add properties to the class itself (if I had a physical class to edit) for different processes such as "energy level", "family number", "mutation", etc. General variables that are either Boolean, Integers, or etc. If there isn't a way to edit the powerpack class itself, is there a way I can use the ovalshape power pack in my own class and add extra properties to it myself?
View 3 RepliesI am just learning about making classes and need to make one with 2 properties.Below is the beginning of a class for ingredients in a coffee machine.But I want sugar and water to also hold name (string) ='sugar' and number(integer) = 4 so its like thisIngredients.coffee.name or ingredients.coffee.number[code]
View 3 RepliesI have a listbox control on my form that has SelectionMode as MultiSimple so I can select more than one item with my mouse. I added a contextMenuStrip to my form and added it to my listbox. I'd like the user to be able to select a few items in the listbox and when they right click > Copy it would copy the contents of the selected items to the Clipboard.
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I'm trying to make a very simple audio tag editor. The idea is that the user can select as many audio files as he likes from a ListView, and a PropertyGrid will then display their tags + their values.When multiple files are selected, I want the property grid to display the values of the tags that all files have in common, and display empty values for tags that the files do not have in common.As an example, look at the properties list in your Visual Studio IDE when you select multiple controls (of the same type for this matter). Select a few Button controls, for example, and notice that the properties whose values are the same (often things like Font, ForeColor, etc) are displayed. Also notice that the values for properties that are not the same (Text, Name, etc) are empty.
View 17 RepliesIf I declare and instantiate an instance of class B within class A, how do I make instances of class A member objects/variables accessible from class B?
View 11 RepliesPart of my program is to simple copy a range of cells ~21 000 rows from one WB (oSH) and copy it to another WB (oSHOut). I've red a lot of posts,tried a lot of variants, but nothing works. Strange here is that if I copy less than 8500 rows, the paste to the destination range is OK. But if I copy the whole range ~21000 rows, vb.net trigers an error - "Copy method of Range class failed". So I tried to do this in several parts - 1 row to 8000, 8001 to 16000 etc. The first copy-paste works OK, on the secon - there's an error
Imports Microsoft.Office.Interop
Imports System.Data.Odbc
oRNG = Nothing
oRNGOut = Nothing
oSH = Nothing
oSHOut = Nothing
[Code] .....
How to get the file path of the Temp directory (% temp%)? I use Visual Basic 2010
View 1 RepliesI 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 an OpenFileDialog. I want the program to copy the file that the user selects to my "temp" folder. If the user doesn't select any file, then it doesn't copy any thing. Here is my code:
Dim Temp As String = "Temp"
If Not Form6.OpenFileDialog12.FileName = "" Then
System.IO.File.Copy(Form6.OpenFileDialog12.FileName, Temp & System.IO.Path.GetFileName(Form6.OpenFileDialog12.FileName))
End If
But it doesn't copy any of my files over that are loaded in the OpenFileDialog.