I am trying to create new variables inside a class after creating its object at runtime. The problem is that I don't know the variable names or the value beforehand so I have to create the new variables at runtime.
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This is a more elaborate explanation of my code. If you observe that in the Eval function I have tried to evaluate Fval(abc). Now the object array abc is not declared in the Test class because it existence is not known beforehand. What I want to do is create an object array abc of length 2 and populate it with some values and when Fval(abc) is called then then the value of index 1 should be the return value of Eval fucntion.
I was create Access database with Access 2003. I create VB project with Visual Studio 2005 Standard With connection wizzard I create coonect with this Access database, select all tablesI see this database inside Data sources and inside Server explorer Test connection is OK When I drag and drop table from Data sources, Wizzard don't create DataGridView, DataSourceBinding etc .. and I see popup window with mesage: Object reference not set to an instance of an object and then "game over"
I understand if i was to create my own class i would need to declare a variable with the new keyword to create an object to access the encapsulated methods properties etc, unless they were declared shared.
dim myVar as myClass = new myClass
But in this next example is where i have become confused. i have added the mschart control to the form and used the hittest function with the following code.
Dim myVar as hittestresult myvar = me.chart1.hittest(e.x,e.y)
Why wasn't it necessary to create a new instance of the class 1st. Does the hittest function return an object or a reference pointer to the object. To clarify what's the protocol for when & when not to create a new instance of the class in use.
VB is telling me to use the "NEW" keyword to create an object instance. For example: Private Sub ScoreTotal(ByVal sender..., ByVal e As System.EventArgs) Handles ListBox1.SelectedIndexChanged
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When I run the "MainStudentScores" form and click on a student with three scores separated by the "|", it should give me a Score Total, Score Count, and Average. However it is giving me an error message at "Scores.Add(intPlaceHolder)" This is where VB is telling me to use the "NEW" keyword. Does this make sense?
I do not want a Windows Media Player control on my form. I am making an alarm clock. I have tried this: Friend WithEvents WindowsMediaPlayer As New Microsoft.Win32. But I do not see a Windows Media Player member. I also asked on the MSDN VB Forum.
I have a class library that contains a number of classes. I would like to dynamically create an instance of one of these classes, set its properties, and call a method.
Example:
Public Interface IExample Sub DoSomething() End Interface Public Class ExampleClass
I am working on an ASP.Net 3.5 solution that I did not originally build. I added a class file named Incident.vb to the App_Code folder like I always do.But in my code behind of a web page, I usually create an instance of a class like:
Dim oIncident as New Incident
But after I type "New", normally I would see my class file he intellisense but I do not. So it does not seem to be able to find Incident.vb. I have not seen this behavior before. Trust me, my class is correct. I have created many class files like this.[code]...
if i create an instance of an object/webpage, is that a complete new object/page based on the original or does it does it just make it accessible? i am almost sure that it creates a new object/page but i would like confirmation. in other words what is the result of this code?
dim Page2 as new Page1 dim Page3 as new Page1
would this create 2 new pages that i can "customize" separately and add different controls to each? heres a brief description of what i want to happen:the user will be viewing Page1 and when he clicks btnCreate i want a page that i created in the designer to be shown and its name and other variables to be determined by what the user chose for room options in Page1. i need "new versions" of this page to be created because multiple users will be creating multiple rooms. i understand that there are more lines of code involved in creating pages and i do have more questions regarding those but i will wait until i confirm that dim Page2 as new Page1 will create a new page. like i said im sure that this does create a new page but i need confirmation. also if it does create a new page, how do i get it to show. i know that response.redirect will redirect me to a dif page but i want show this new room on top of the old one.
when i compile my code i got "use the new keyword to create an object instance" at this line " accounts1(sd).Name = textBoxUser.Text"
My code is below.
Private Sub buttonSave_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles buttonSave.Click If comboBoxAccounts.SelectedIndex >= 0 Then
Private Sub textadd(ByVal sender as Object, ByVal e as System.Windows.Controls.TextChangedEventArgs) txtfirstname.Text = txtdisplayname.Text 'TODO: Add event handler implementation here. End Sub
Do I have to instantiate description every time for different method? Or should I use static? Here's how I'm doing this now: What is the best way of handling this kind of situations. it seems that I repeat this line:Dim description As BLLDescription = New BLLDescription() without any good reasn.
Protected Sub Button8_Click(sender As Object, e As System.EventArgs) Handles Button8.Click Dim description As BLLDescription = New BLLDescription()
I want to create a class that will "search" for something. Basically I load up the "search item" when the class is created and inside the class is logic to do the "search". The result of this logic will be more "searches" that I want to start. How can I have the logic in the class create another instance of the class itself?
I have an application that reads another processes memory.I initially had multiple scanning threads for the various areas I needed to read.This was processor intensive so I decided to go with the observer pattern.All was well except that I am having a weird behavior.Here is what is happening.I have 2 radars (overlay and mapped)Both have a watcher class that attaches to the memory scanner and is notified on a new list of mobs.so I open radar 1 (mapped) it attaches it's watcher to the scanner and waits for mob list update notifications
Open radar 2 (overlay). same thing happens and another watcher is attached.all is well and good so far.Now there are properies on the mobs in the list, one of which is IsFilteredOut.This property is set in the radar code after it receives the list. Now the weird behavior is that no matter what I do, the second radar to be opened changes all the properties of the mobs in the list of both radars.It is as if I am passing the list by ref, but I am not.I actually create a new instance of the moblist class every time I pass the list.Here is the notify code. As you can see I create a new instance of the moblist class each pass.
Private Sub NotifyMobListUpdated(ByVal Mobs As List(Of MobData)) If Mobs IsNot Nothing Then For Each w As Watcher In _watchers[code].....
I'm creating what I believe is an mdi app.I have a login form.I have a class for security.My login form creates an instance of the security class. There are all kinds of security parameters for each user (permissions to different things, etc.)These parameters are part of my security class.Once the user logs in, many other forms will all be opened and closed within the main mdi frame.All of these other forms need the information of the security class to know what the user has permission to do.Do I have to create a new instance of security class for every form in my project? Isn't there a way to store this stuff globally somehow. Retrieve once from the db at the start of the app during login and just get it from this global area everytime?
I have this class Framework.Asd.Human with a public empty constructor. and i want to be able to dynamically create an instance of it from a string input "Framework.Asd.Human". Is this achievable? (in java and C#)
I have a class inside a class.I need to expose the properties of the 2nd class to other classes, therefore it is public.However, I do not wish other classes to be able to create instances of this 2nd class, it should only be instantitated from its parent class.I thought I could resolve this issue by making the constructor of the 2nd class private, but this even prevents the parent class from instantiating its child class! How can I work around this, do I have to make the constructor public and allow anybody to create an instance of the class?
I am attempting to create a new mobile app using VB in visual studio 2008. I select "File" "New Project". Select "Smart Device" in new project window. Select the "Smart Device Project" from templates. Select ".NET Framework 3.5". Select "OK" and get the dreaded "object reference not set to an instance of an object"
Use the "new" keyword to create an object instance & Check to determine if the object is null before calling the method. I'm reading text from a text file using the following [Code]
I have created a class (pasted below in case I did something wrong) for which I want to create an instance that is usable across forms/modules. I can create an instance of the class in a single form/module no problem via DIM User as New User but how do I go about create a public instance accessible from all parts of my program?
I am developing an IT Asset Tracking application using VB 2005 and SQL Server 2005 Express edition. Will I need to create classes to represent objects such as Computers, Printers, Scanners/Faxes, Contracts, Purchase Orders etc or are there any other approaches.For example, if I am correct, I will have a class called Computer and its properties will include Make,Model,CPU,Hard Disk,Memory etc. Is this the right approach.
Computers can be split up into Desktop PC's, Servers and Notebooks. Would I have to create separate classes for these as well or would they be ok under the Computer class.Once I create an object from the class, how can I use the object to interact with the SQL db.I am a beginner to VB.NET 2005 therefore I am slowly getting to grips with OOP.
I have created a synchronized queue and am using SyncLock on the SyncRoot property of that queue when I invoke the Enqueue/Dequeue methods. The methods are invoked from instances of standard producer/consumer classes.Is that a proper use of the SyncRoot property?
Would it be better practice to create a private shared object in each class and lock on that instead?
String s = "test"; String is a class, so to use it we should create an object of it. But rather we just make a reference of it and give it a value. How is it possible and what concepts are used in it. The metadata of String class shows the following :
is it possible to use a dll in my project without having to create an instance of the dll? for example I have a dll that has three basic math functions:
I have 3 controls sharing the same Bindingsource.Each control will require a different parameter for the query call to the DB to populate the proper controls data.However each control is filled with the same data and using one ctrl has the same effect to the thre controls. The controls all mirror eachother.how can i create a new instance of the table adapter?
VB is telling me to use the "NEW" keyword to create an object instance on the highlighted line in the code below, when I click on the button to add a row to the datagrid. Here's my