.net - Allow Math To Occur On Instances Of Class?

Nov 27, 2010

Is there some interface I can implement to allow basic comparisons and math to happen as it would an integer?

For example, let's say I have the following class:

Public Class Something
Public SomeBigNumber as UInt64
End Class

I would like to do something like this:

Dim SomethingA, SomethingB, SomethingC as New Something
....
If (SomethingA-SomethingB) > SomethingC Then
'Do stuff
End If

I was hoping to be able to implement some interface (if that is even the right term for it) that would return the UInt64 contained in the class for comparison and math, if possible.

View 1 Replies


ADVERTISEMENT

Defining A Class For Multiple Child Class Instances?

Feb 10, 2011

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

View 4 Replies

Only Calculation In Radian In Math Class?

Jan 27, 2010

I use Math.Tan(str) for example (str = 35)

I become 0.47... But how can I calculte it in Deg., and Grad., to?

View 6 Replies

Create A Static Class Like System.Math

Mar 6, 2010

I have a module with generic constants, subs and functions.I would like to be able to use the module in multiple projects in one solution.I also want it to work like the class System.Math, where you do not need to declare and instance of the class before you can reference it.[code]I want to be able to call ClassLibrary1.MyGenerics.Half() just like I can call System.Math.Abs()

View 10 Replies

Multiple Instances Of Class?

Mar 29, 2010

I have the following problem. (VB.Net 2008)I have created a class (myFirstClass). In this class there are a lot of calculations being made wich gets fired by events in that same class.Now i want that same class to be able to fire more instances of itself. However i noticed that each time i fire an event from a Sub the program waits till the event is finished before going to the next line of code. This is a problem since i want the event wich fires a new instance of the class to fire it and forget about it.

View 7 Replies

VS 2010 Hmwk - Display The Largest And Smallest Using Math.max - Math.min

Mar 5, 2012

well i am having a couple of issues with this particular homework problem and this is my first programming class so there is probably quite a few mistakes well the homework problem is to take three double values entered by a user and display the largest and smallest using math.max and math.min and display the smallest and largest so i thought i could use a listbox and take the values that went to the listbox and assign variables to each so i can try to use each variable in the math.max and min but im not making it to far and i actually might be way off

[Code]...

View 4 Replies

Added To Each UserControl (different Instances Of The Same Class), A Little Map?

Apr 28, 2009

I have a form whose purpose is to let the user to load map files.The form may manage a variable classes of maps, and each class have his own UserControl.To make it more user friendly, I added to each UserControl (different instances of the same class), a little map, showing a small picture of the map, and some data, as bound coordinates.

The problem is, that it looks really ugly. The maps are so big, compared with the rest of the UserControl (who contains just a button and a textbox to search for files).I wish to fix it, but I din not see an elegant way to include the pictures and info.I attach a form screen capture with two UserControl.I would like to get some tips for more experienced users. There are some guidelines?

View 5 Replies

Creating Instances Of Own Class At Runtime?

Sep 3, 2011

info on creating instances of my own class at runtime. Simple project for family recipes but would like the option to add new recipes with new instances of my own food Item class at runtime. Creating my own class,no problem. Storing the data in an XML file, OK on that as well. My issue is creating new instances of different food item class as I use this program over time

View 13 Replies

Multiple Instances Of A Custom Class?

Feb 15, 2009

I have a sub that runs on a button click which I want to create a new instance of a custom class and add it to a list of already created instances of this class. I want the result to be a List Of collection of all of my class instances.

My problem is that each time I run the sub, it simply 'overwrites' the first instance of the class and adds a copy of it to the list instead of writing a new instance. My code is along these lines

dim objFixture as new clsFixture
For n As Integer = 1 To intNoOfChannels
objFixture.SetChannelAddress(n, intCurrentChannelTotal + 1)
intCurrentChannelTotal += 1
next
lstFixtures.Add(objFixture)

View 7 Replies

Passing Variables Between Instances Of A Class

Jun 17, 2009

I created a program a while back, in the traditional VB.NET way by drawing a bunch of forms. I have started playing around with creating the forms at runtime using classes. I have a placeholder form called frmStartup which merely calls the CreateLogin() sub from the CreateFormClass. The CreateLogin() sub creates a new blank form, then calls the grpbxLogin(), btnSave() and btnExit() subs from the FormElementClass which adds all the buttons and textboxes to the form. Within the FormElementClass, I have associated btnSave and btnExit with event handlers. These even handlers call subs from the DataProcessingClass. The event handler for Exit works just fine.I am having a problem with the Save event handler. Precisely, I don't know how to pass either the username or password from the Login form to the btnLogin_Click() sub in the DataProcessingForm. I have tried using Me. and frmLogin., but the program doesn't see either of those. If the Login form is an instance that is disposed of once another Sub is called, then it won't exist later on to call from. I have tried declaring variables and passing those along to btnLogin_Click, but no matter where I put it, the program doesn't see txtbxUsername.Text or txtbxPassword.Text. Not even from within FormElementsClass, which is were the boxes are created.Any ideas on how to pass variables in this case? I am not even sure what you would call this such as passing between classes, or passing between instances.[code]

View 9 Replies

Repor Declaring Class Instances?

Oct 20, 2008

I've decided to forget the d@mned custom code because everything I do with comes up with errors I don't know how to fix and it seems no one else does either. Or they do and they're keeping to themselves.

I put the functions that I needed to use in a class called MsgBoxOperations. The file name is MsgBoxOperations.vb In the report, up on the standard bar where file, edit, view, and all the other stuff is, is one that says report. You click that and go to report properties and it brings up where you can name the report and put in custom code...(hate custom code right now...) and where you can put references and class instances. Clicking on the Reference tab brings up wher you put in your references and classes.

In the classes area it asks for the Class Name, which I put in MsgBoxOperations, and the instance name of that class, this case mbo. I get that far and put in those two things and save it. Then I go to the textboxes where the values need to be. I put in the text box: =Code.mbo.GetStartDate

I've already tried taking the Code. part out and it screams that mbo isn't declared. So it does have to be there. I go to run the code and comes up with this error: QuoteError in class instance declaration for class MsgBoxOperations: [BC30002] Type 'MsgBoxOperations' is not defined.

I've posted before and still have received no help or someone tried to help but then stopped when their suggestion failed and then no one else wanted to help. I've googled this problem to the point where every link that it comes up with I have already clicked and found their information useless. I've got a freaking migraine because of this issue and have been in tears over it more than once.

View 14 Replies

Alphabetize An Array Of Objects That Are Instances Of A Class?

Nov 1, 2011

I have an array of objects 2000 that are instances of a class. I want to alphebatise these objects by a detail of the class.

View 1 Replies

C# - Respond To Events From A List Of Class Instances?

Jan 21, 2011

I 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

[Code].....

View 2 Replies

Creating Instances Of A Class That Has Several Readonly Properties?

May 24, 2011

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?

View 2 Replies

VS 2010 'Infinite' Public Instances Of A Class?

Jan 24, 2012

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?

View 2 Replies

Creating An Array Of Instances Where Instance Could Be Base Or Sub Class?

Oct 31, 2011

I have a class structure and am attempting to create an array of object instances from the class some instances are parents and some are children Code snippets,

Parent Class object
Option Strict On
Option Explicit On
Public Class cTransportItem

[code]....

View 1 Replies

Ensure Instances Of Class Finish Before Main Terminates?

Feb 14, 2012

I have a MultiThreading issue and conceptual question using Visual Basic (but it applies to almost all languages). [code]...

View 2 Replies

MovablePictureBox - Set The Flags In All Other Existing Instances Of The Class, When It Is Set To True In The Selected PictureBox?

Apr 17, 2010

if I have several of these movable PictureBoxes added to a Form (Form1) and want to display a selection rectangle only on that PictureBox, that is just selected,then I think I should use a flag to mark whether a PictureBox is selected or not. The flag could be used in paint event to decide,whether the selection rectangle is to be drawn or no .To add a flag property to the new class is no problem. But how can I set the flags in all other existing instances of the class, when it is set to True in the selected PictureBox?

View 1 Replies

Object Oreinted Random Failure - Define Two Instances Of Class And Configure ?

Oct 27, 2009

I am having a problem with a and OOP class i made that contains a sub that creates random integers.

Problem is if i define two instances of this class and configure them(name in this case) then they both display different names but the random integers are ALWAY the same. in this case having the integers the same kinda kills the idea of the program.

Is it possible that the random part only every works for one class, but if .NET is fully OOP then this should not be possible... right?

Some of my Code (broken down to something smaller) i will display for obvious reasons.

Code:

View 11 Replies

VS 2010 Sorting A Listbox (after Trying To Copy Class Instances Properties To A Temp List)

Jan 25, 2012

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:

[Code]...

View 19 Replies

"Import" A Static Class In C# Such As System.Math?

Oct 9, 2010

Is there a way to "Import" a static class in C# such as System.Math? I have included a comparison.[code]...

View 3 Replies

Use A Decimal Instead Of A Double (why Then Do Microsoft Use A Double For Most Math Class Functions)

Aug 15, 2011

For greater accuracy I should use a Decimal instead of a Double ( so I've been told ). Why then have Microsoft chosen to use DOUBLE for most of the functions that return a floating point value in the Math Class?

[Code]....

View 9 Replies

Windows Service: Multiple Instances Of The Same Service Class?

May 3, 2011

When you create a Windows Service, you create a list of the services you want to start. The default is this:

ServicesToRun = New System.ServiceProcess.ServiceBase() {New Service}

Can you have multiple instances of the same Service class (that bind to different addresses or ports), like this?

ServicesToRun = New System.ServiceProcess.ServiceBase() {New Service("Option1"), New Service("Option2")}

Or will that cause problems? Should we use two different classes instead?

View 1 Replies

Create A "shared" Variable That Is Shared With All Instances Of A Class?

Jan 14, 2011

I seem to be drawing a blank. I'd like to create a "shared" variable that is shared with all instances of a class but not classes that inherit from it. For example.Class A: Shared list As New List(Of String): list.Add("A")

Class B Inherits A: list.Add("B")Class C Inherits B: list.Add("C")The end result I'd like is that any instance of A has just A in the list. Any instance of B has A and B in the list. Any instance of C has A, B, and C in the list. I can accomplish it by creating Instance variables, but I have to construct the list for each instance of a class. I'd like to construct it once for a specific point in the Hierarchy and then share it accross other instances of that class.

View 12 Replies

Save Prompt If Changes Occur?

Mar 15, 2012

In my application, i have put a question on form closing if the user wants to save the changes?. But right now, i have just put it in default whether they make changes or not.I thought of prompting it on text change.. but the text automatically changes on load as it retrieves data from sql server.

View 15 Replies

Using Catch For An Exception That Does Not Occur

Mar 25, 2012

What is the code that I can use to describe what happens when there is not just one exception in a'Try...Catch..Finally...End Try' statement? For example: 'Catch' is used to describe what happens when a certain exception occurs, but what can I use to describe what happens when a certain exception does NOT occur?

View 11 Replies

Play Sounds When Certain Events Occur?

Oct 22, 2009

me and a partner need to play sounds when certain events occur, however, every method we try..

My.Computer.Audo.Play("file.wav")
or?
Sound.PlayWaveFile("file.wav") from this class: http:[url]....etc they all don't work

They do NOT throw any exceptions, they just dont play the music, the test demo of the Sound Class works like a charm, its just not working in our project..same with My.Computer. Audio. Play.what could we have done to make it so that we can't play sounds from our application?

PS: this problem occurs on all of the computers we test it on, yet the normal sound-playing methods seem to work on all of those computers when they are implemented in other projects.. its just not working in these instances

View 5 Replies

When Click The Button The Event Occur Twice

Dec 11, 2009

Private Sub done_Click(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs) Handles done.Click
Dim s As Integer = ComboBox1.SelectedIndex
Dim t As Integer = ComboBox2.SelectedIndex
Dim x As Integer

[code].....

When i go for r <> 0 then it occur twice.

View 16 Replies

When Does DataBinding Occur For Drop Down Lists

Jun 12, 2012

Here is my drop down list and data source. My question is.. when is it possible to set a defaulted selected option for the drop down list, aka when have all the dropdownlists been databound and their ListItems populated? I have tried Page_PreRender, age_PreRenderComplete, Page_Load.I have read over MSDN's Page Life cycle event which suggest Page_PreRender.

<asp:DropDownList ID="ddlRampStandard" runat="server"
DataSourceID="RampStandardDataSource" DataTextField="StandardName"
DataValueField="StandardName" RepeatDirection="Horizontal"

[code].....

View 1 Replies

Why Does System.Reflection.TargetInvocationException Occur

Feb 11, 2012

I am making a program that is sort of a frontend to all my other apps. I put the EXEs of those apps into the resources of my frontend. The problem occurs when I try to run the EXEs from memory.

I keep getting System.Reflection.TargetInvocationException on the line:
entryPoint.Invoke(RuntimeHelpers.GetObjectValue(objectValue), New Object() {New String() {"1"}})

[code].....

View 12 Replies







Copyrights 2005-15 www.BigResource.com, All rights reserved