Build A Car Class - Instanciate Many Objects Of Calss To Move More Than One Car
Feb 14, 2009
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I have build a Car class as follows:
Code:
Public Class Car Dim CarState As Integer Dim CarPicture As New PictureBox
Public Sub DriveIn() 'This sub to drive in the car to the lot. CarState = 1 Dim x As Integer For x = 1 To 45 If x <= 12 Then CarPicture.Top -= 3 Threading.Thread.Sleep(100)
[CODE]...
Then i tried to instanciate many objects of this calss to move more than one car as follows:Public Class Form1
Private Sub btnDrive_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDrive.Click 'Dim objCar As New Car() Dim objCar As Car objCar = New Car objCar.DriveIn() End Sub
Base class has one field to hold numeric balance value. With 2 methods that accept arguments for adding and subtracting the new input calculating new balance. Sub class has four fields dates, transaction, memo and amount.I have a deposit form, and withdraw form. Each time one transaction is entered it creates an object with sub class fields, then adds to the account collection. My problem is not understanding how to call the deposit/withdraw method and pass the current transaction amount back to the base class to alculate the new balance. Does anyone have any links to information/tutorials on how to perform something like this? As you can see with my code I have tried various different approaches without any success.
What does this error mean? I havent modified anything in the designer code, but its giving me an error? WithEvents variable 'Move' conflicts with event 'Move' in the base class 'Control' and should be declared 'Shadows'. The error relates to Friend WithEvents Move As System.Windows.Forms.DataGridViewCheckBoxColumn
If I have a class that inherits another class in which there are objects that are disposed in the dispose() procedure, do I use mybase.dispose? ex Class A inherits Class B. [code]
I am extremely new to VB but i have most of the basics down fairly well. I can create buttons and move objects with arrow keys, for example. I am using VB Express Edition 2008. What I am trying to do is make a very basic game. So far it was going great until a little problem stumped me [see title to see where i am going with this]. Before i added buttons onto the form i was able to move my little circle man with the arrow keys up, down, left and right. When i added buttons it no longer allowed me to do such things. Now moving the arrow keys only allows me to select buttons without the mouse. It is really frustrating because i have been working very hard on this and a problem this small could ruin everything! ;)
I was wondering if there is a way to move objects with arrow keys and use buttons on the same form and if so, how do you do it?
Im trying to make a radiobutton move diagonaly, (Dont ask why a radiobutton, i did it in college last week) For some strange reason though I need another radiobutton just going across the screen in order for my diagonal radiobutton to move.I would like to develop this into a game like pong, when I have gone further into VB.
I cannot move objects (such as buttons, listboxes, etc) in the Windows Forms Designer by clicking and dragging them with my mouse. This gets really annoying after a while. However, I can move them with the key pad (up down left right) and by changing the location property. Does anyone know what is going on?
Oh and I'm running vista with all the service packs and latest updates, and I don't have any viruses (scanned with MBAM, Spybot and Avast)
[code]The reason that this is a problem is that this is a collection of EventBase objects, but I'm trying to populate it with child classes instead. For example, I might have a JumpEvent class that inherits EventBase, and this is being put into the EventBaseCollection. That means that value.GetType() returns the type of JumpEvent, which as you might guess does not equal the type of EventBase.The goal of course is to simply loop through all of the various events without having to know anything about the sub-classes. Is there a way to determine the type of the base class so that the OnValidate call will work? Or is this just the wrong way to go about it altogether?
I know that by clicking before an object is finished moving, causes the object to move again, prematurely. I have tried using "If Timer2.Enabled = False Then move. This does not work. Is there another way to disable either the mouse or program execution until the animation objects are finished moving?
I am trying to build a class that works with a form, but I keep getting the dreaded "Object reference not set to an instance of an object" Error.The form basically collects test grades and assigns them to a collection.My class code is as follows:
Public Class Scores Private colScoreCollection As New Collection Public mintSum As Integer Public mdecAverage As Decimal Public mintMinimum As Integer
[Code]...
I had a similar project I was working on that had a collection in it, but now that one is giving me the same error. It there something with my version of Visual Studio that is causing this error possibly?
I am trying to build a class. I am having a difficult time conceptualizing how a class is built and how it works. I want to be able to build a USEFUL class and implement it in an application.
so my question is relatively simple, can I create VB6 application that references a class in a dll, and then substitute that dll for another at runtime?Now my intial guess is... no chance in VB6.
So my thoughts turned to a VB.net interop dll. Could I do it in here, and then call the interop dll from the VB? but I'd be happy if someone knew differently.The only thing that I think would actually work would be DI in .Net, but I'm limited to .net 2, or 3.5 at a big push, so I dont know if that is possible.
I have a dll that a specific site uses, but we dont want to ship that out to everyone. Instead, we want to build a clone dll which just has the interfaces setup so that the VB6 build will complete.When it gets to the site that needs it, they want to replace the dummy dll, and drop in their version instead.
Note: We do use RegFreeCOM when its gets installed, so I do have the manifest files that I could play around with if needed.
I have this application that users can make exams that contain exercises of different ... whatever. Anyway when student takes the exam he chooses it from a list and then all exercises are loaded from database. I wanted to make loading process faster by loading only first exercise data and putting others in background thread.
Actually in other parts of this application something like that is done but not by me. Basicaly an api class is built around BackgroudWorker and i can use this class to put certain functions of objects to be executed in background. The idea sounds great but in real life there are some problems with it. For example for historical reasons this application uses global functions and reader and uses global connection to Access database which means if in background something is being fectched from data base and you try to fetch from database in main thread then a „reader is already open" error occurs. To avoid this error if im doing something in main thread and want to fetch some data i have to move my function from main thread into background worker function list. And basically this in my opinion stinks cuz you end up with many delegātes, invoked checking and thre result... I was just thinking that there maybe is another way to allow (maybe with events) not put everything in background in case something is happening in bakcground but rather allow bgworker to finsih current thing, then do my thing and then resume bgWorker and not create havoc in code.
Basically i have to classes - exam and exercise that each implement many interfaces (like IExercise, IExerciseResult, IExerciseYesNo, IExerciseMultipleChoise etc.)And then i have DataBase classes like ExerciseDB, ExerciseResult etc. That have functions that preparē the sql params and call sqlHelper functions.And for example when i load up exam i go throug all exercises and call LoadData function that in turn calls ExerciseDB function selectData and then i put the returned data in Exercise object. And this type of thing of course would producē error if i at the same time would try to register the answer in database for another exercise. Ofcourse i could always check and put this in background... but as i said i'd rather want to work with database from both threads.
I'd like to build a class where I always have a button at the bottom of a form.Then when I drag and drop the button, It has to make a copy of that button called "button1", if I drag and drop the button again I'll have another button called "button2" and so on.But If I drag and drop the "button1" or "button2" they shouldn't duplicate as the original. And this is the problem I can't sort out.
This is my class:
Imports System.Windows.Forms Imports System.Drawing Public Class frmTablesEditor Inherits Form
I am working on a VB NET project and had the strangest thing happen.I created a class file(just like a dozen or so I have already created). I wrote in the code to access it. The autocomplete found the class, filled it in and colored it blue, just as it should.But, when I run the app, I get a type is undefined error.
There is nothing in the class yet. And there is really no code to post..it is as straight forward as I described.I tried restarting VS; Deleting and recreating the class; Deleting the class and creating a new one with a different name.
Is there something in the VB NET configuration I can check to see if it is not being added somewhere?
I found the problem. I have 2 projects in one solution. They both share some classes that were trying to use my new classes. When I hit F5, both projects are compiled, and since I hadn't shared the classes with the second project, it errored.
So, now my question is changed; How do I specify to only build the specified Startup Project when debugging?
I'm fairly new to the concepts of OO programming - actually programming in general as I am still a student. I'm currently working as an intern in a department that has me coding a new structure that will probably be the base for all their applications to come. So I believe I have the idea behind OO down where you create "basic building blocks" and then expand, expand and expand, until you arrive at the most complex object (for the time being). I need to put all these "advanced" objects into one but how many is too many? Can I have 100 objects inside of this bigger object if it requires all these "parts".I really hope this question makes sense to everyone. I'm sure the answer is not going to be a definite answer either but I just need a rule of thumb to go by. I'd really hate to have 100 objects inside of 1 big one if there is a better design/programming technique. [code]
I'm moving some stuff around in a program. How do I move a class (or enum, etc) to a different namespace? Right now I am getting 102 errors because even though VS can update name changes, I don't see how to get it to update a move to a difference namespace.
EDIT: Okay, to be more precise, I am moving a class up the namespace tree. So, not just a different namespace, but actually getting rid of the last namespace qualifier.
when using variables in object names.I have a Public class which is called "Tank".In that class, there is a public property called "direction" of an integer type.I keep getting the error:
"Tank is a type and cannot be used as an expression"What I'm doing wrong here ?
Public Class mainroutines() Create Instances of tank Private Tank1 As New Tank()[code]....
I need to create an array of a class type. Populate the values in the class and then pass the array to a subroutine. I havent figured out how to do this properly as I get a null reference exception. Can someone show me how to create/instantiate the array of objects? Here is a simple example with only one property named "_momentum". My actuall class has about 10 properties/variables in actuality
I'm wondering on how you would go abouts instantiating a class that contains other complex objects. for example an Payment Class which has Date,Time, etc.. and it also holds a reference to a paymethod object which has id,Type,Description etc.. How do you instantiate the payment class with all the other objects without one or the other failing, how do you create the payment class which doesn
How can I make an array of objects in VB.net. Here is the requirement. Basically I have a class named hotel. I need to dynamically add customers to the hotel class using the Customer class. So basically if in the Hotel class I can have an array of Customer objects that would be great. How can I do this in VB .net ?
Public Class Hotel ' I need an array of Customer objects. objCustomers End Class
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.
