I have a function that will be passed an object that contains MANY variables. These variables all get stored in a database. Later a new object will be passed to my function and most of the time it will be identical. But sometimes one or two variables will be different and I'll have to take various actions based on those changes. Other than looping through every variable and comparing it to every stored version of that variable, how might I do this? Can I some how generate a hash value for an entire object? Since the object will be the same most if the times it is passed to me this would be a quick way to determine that nothing has changed.
I'm trying to compare two variables of type nullable(of boolean) in VB.NET 2010. One of the variables has a value False and the other is Nothing. Now I was expecting the following expression to evaluate to true, but this is not the case:
Dim var1 as nullable(of boolean) = False Dim var2 as nullable(of boolean) var2 = Nothing
[Code].....
Why don't I see my MsgBox? How should I compare two nullables (of boolean)?
I created a SRT program in vb6. works great. I thought it would be a good time to port it over to vb2010 for obvious compatibility issues. the following will not work, even though through debug; all the vars are correct - it just wont come up.
' Timer1.Stop() : MsgBox("start: " & CaptionStart & " end: " & CaptionEnd & " smptime: " & WMPTime) : End If (CaptionStart <= WMPTime) And (WMPTime <= CaptionEnd) Then txtCaption.Text = Caption '// HIGHLIGHT IT IN THE LIST
[code]....
in the above its simpler (why I like vb6) and works perfectly. I am most likely "not seeing the forest for the trees" syndrom.
I've got 3 forms that have exactly the same functions, so I decided to create an interface.
public Interface IExample public sub Add() Public sub Edit()
[code]....
At this point, objfrmExample is now instantiated, even though I've not done a "objfrmExpample = new [what-goes-here?] " and I'm curious as to why.I could possibly guess that because you cannot instantiate an interface variable, then vb.net automatically creates an instance. But thats just a guess. The question is , what is meant by declaring a variable of type Interface, and how does it work?
Here's what I'm looking to do. I have an array of objects that all implement a particular interface. What I want to do is search that array of objects for a particular object type.I have to do this in several places, so I'm trying to create a function where I pass in the object array and the type that I'm searching for, and have that function return the object that matches that type - or nothing if no match is found.I wrote the following, but it isn't working, so I'm missing something:
I want to make my own xml-serializer class because I need other formatting than the System.Xml.Serialization.XmlSerializer does. My idea is to treat properties of primitive type (such as Integer, Double, String) as XmlAttributes.To properly implement a usable Xml-Serialization I need to know which variables point to the same object (the binary serialization behaves this way). Because one object should be serialized only once in order that the connections don't get lost.On the side of XmlSerialisation I have the idea to insert a path to the class as a special XmlAttribute.
I'm building a litle console app that involves a control hierarchy -- there are screens, and inside of screens you can compose controls together.
You can add controls to a screen by declaring member variables (which all inherit from AresControl). The control constructor takes a simple coordinate pair. It looks like this:
Public Class IntroScreen : Inherits AresScreen 'Controls Private LabelSelect As New LabelControl(72, 0)
[Code]....
This would result in cleaner, convention-based code. But try as I might, I can't get it to work - I can walk the member variables of a type, but I need to walk the member variables of a live object.
I am writting a VB .net (3.5) applivcation which references a COM object. I can call methods on the COM object fine provided that they don't require any variables to be passed. I have been told that you can only pass a maximum of one varaible to a COM object, I really don't believe that it true
This is my first post here at Xtreme VB Talk. I just started programming 2 semesters ago. I am currently working on a program but I am having a little trouble with the length. I am trying to take the integer entered in a text box and using it inside the name of another object.
I am trying to figure out how to use variables to define which object to update. I could of course use a case statement to pick the object based on a variable, but it seems to me like there should be a more direct way. Here is a smaller example of what I would like to do.In my form I have 4 picture boxes (pbox1, pbox2, pbox3, and pbox4). I then want to change the image in one of the boxes, but the box I want to change will be determined by a variable (say maybe a randomly generated number). Is there some way to dynamically concatenate the "pbox" with the number that VB would understand it and use it as an object?In this example I could easily build a case statement to handle the selection, but in my real program there will be many more than 4 options.
I'm trying to write a simple game ui, it is grid/tile based, and i have the grid built using grid column and row definitions and I'm successfully placing objects in various grid locations. I am currently stuck as trying to build the player object. I want a single object reference to represent the various components of the players piece.
Currently I am using a polygon to represent the piece on the grid. Eventually I want to replace this with images or something. I want to add in properties for what weapon and armor it has equipped I want properties for health
Essentially in code i want something like this
dim player1 as new playerobject player1.polygon.points = 0,0 60,30 0,60 player1.health = 100
[Code]....
I can instantiate all this as separate variables etc, but I'd like to have a singular reference that contains all the variables, properties, objects, controls etc.
I'm using vb .net in vs 2010 (and no, I'm not looking to write in something else)
I'm trying to write a simple game ui, it is grid/tile based, and i have the grid built using grid column and row definitions and I'm successfully placing objects in various grid locations.I am currently stuck as trying to build the player object. I want a single object reference to represent the various components of the players piece.
Currently I am using a polygon to represent the piece on the grid. Eventually I want to replace this with images or something.I want to add in properties for what weapon and armor it has equipped I want properties for health Essentially in code i want something like this
dim player1 as new playerobject player1.polygon.points = 0,0 60,30 0,60 player1.health = 100 player1.weapon = "axe" etc
I can instantiate all this as separate variables etc, but I'd like to have a singular reference that contains all the variables, properties, objects, controls etc.I'm using vb .net in vs 2010.
I have created a class called 'MyAddress' and in the form load event i am adding few objects of that class to the combobox. I want to know how should i set and read the values of the member variables of that selected item of the combobox. I have tried this and is working, but i am not sure whether it is the way to do
vb Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
I have a listbox of a object called Account, which has 2 fields, password, and username. How can I compare a New Account to all the accounts in the list and see if the password matches?
So, how can I set (if it's possible) the localization for these labels? I've this kind of assignment in modules and not in the form. It's possible to set a resources file also for modules?
Last year (2010) I came across a FANTASTIC command that allowed me to take a string of variables with a common delimiter and break it all back out into separate variables (possibly an array) with one statement.
[Code]...
As long as the delimiter was a unique specifiable character, this one-statement command could break it out into elements. my memory and point me in the right direction.
they need to make some compare version between host version and client version.. and each 1 version different will download the file to the client..[URL]..with both example, how can i make a program in VB.NET just like i said just now?
I have code, shown below, that works all except for 1 thing: The variables being passed byRef get passed, but once modified in the else section of the "if me.invokerequired" code of RecordData, the variables are never updated in the calling function. To reiterate, the calling function does not receive the updated data that is in the variables custid and amt.When debugging, I see the data change in the else section of "if me.invokerequired", but once it returns from the callback the data is missing.[code]
I define some global variables of a class as follows:
Private Class MyClass Private var1 as Decimal Private list1 as List(Of string)[code].....
But I found that after this form is closed, all above variables, var1, list1, list2 still exist in memory. I thought they should be collected by gc since the form is already disposed as I confirmed.
Add: I have monitored half an hour after the form is closed. But these variables are not collected by gc. I have an automatic update procedure on the form which uses above variables.Since the above variables still hold values, the automatic update procedure is always called which causes exception. (One quick fix is to check if form.isDisposed in update procedure. But I do not think this is elegeant. Besides, these variables occupy memory.)
Does the memory used in declaring variables are reclaimed by the OS when these variables go out of scope?Does the memory used be released by setting thier value to nothing? if not, then how can I force the garbage collector to run or excecute at a certain/desired time..How about in Windows Forms..How can we make sure that the memory used in initializing and showing forms be released if those forms were closed?
Question 1: What is the difference between "Background Worker" and "Worker Pool" as indicated within the MSDN samples provided.
Question 2: I noticed while using, AddressOf _Function_, variables cannot be passed; what would be an efficient solution to this?
Question 3: While using multithreading is it required to invoke before setting variables, or only form properties?
Question 4: While using System.Net.Sockets is it safe/efficient to use Application.DoEvents while waiting for new data; or would be using a Do While loop be fine without DoEvents since the action would be multithreaded? Note: there can be up to 2000-3000 sockets in use at a time.
I'm new in .NET programming.I have a class Form1 that includes Button1_Click event.Button1_Click creates a multiple Text Boxies at run time)Here is the class:
Public Class Form1 Dim shiftDown As Integer Dim counter As Integer
I am somewhat new to object oriented programming and am attempting to flatten a Linq object hierarchy by using a shim class.how to initalize a derived class with property values from a base class?I have two objects, a base object with about 100 properties, and a derived object which inherits from the base object and adds a few additional properties beyond those of the base object. My simple constructor creates the derived object, but I am looking for a way to initialize the derived object properties with values from the base object.Right now I am using reflection to iterate over the properties individually and I suspect there may be a better way. The following example shows my shim class constructor for the derived class, and two properties:
newProperty1 - a new string property of the derived class
flattenedProperty2 - a new string property of the derived class, copied from a 2nd-level object of the base class
Code example:
Public Class derivedObj Inherits baseObj Private _newProperty1 As String[code].......
Is this the correct constructor approach to flatten the object hierarchy using a shim class? My second question relates to initialization of properties in the derived class. The constructor above creates the derived object, but what is the best way to initialize the derived object properties with values from the base object? The following code uses reflection to iterate over the properties individually, but I suspect there may be a better way.
Code example:
' property names are in the string array fieldNames
'baseObjQuery is an ienumerable of baseObj
'derivedObjList is a list of derivedObj[code].....
Is there a simple way to initialize values for the properties in the derived object based upon the values of the common properties in the base object?
