Add A Constructor To An Existing Structure?
Oct 31, 2011I've been searching for a while now and can't find a way to add a constructor to the Rectangle Structure.
Is this even possible without inheriting from the class?
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Why It Is Not Necessary To Initialize All Members In Parameterized Constructor Of A Structure
Jan 19, 2012When it comes to constructors in a Structure type ,it is fact that we can not explicitly provide the default constructor .It is provided by the runtime. Ok, another point that is applicable to C# language is that if we are defining a parametrized constructor then it is compulsory to initialize all fields . We can not leave any field uninitialized , since the runtime will not call default constructor if we are calling parametrized constructor .Its logically right , but in VB.NET language , actually you are free to leave any of the fields uninitialized in your parametrized constructor.
[Code]...
Add An Enum To An Existing .NET Structure, Like Date?
Feb 23, 2011What I am wondering is, is it possible to create an enum and attach it to the DateTime structure? Extension Methods come instantly to mind, but I don't know of a way to pull this off using them.
Dim july As DateTime.Months = DateTime.Months.July
Public Enum Months
January = 1
[code]....
Add An Enum To An Existing NET Structure Like Date?
Oct 26, 2011So apparently Microsoft does not have a Months Enum on their Date structure.What I am wondering is, is it possible to create an enum and attach it to the DateTime structure? Extension Methods come instantly to mind, but I don't know of a way to pull this off using them.[code]...
View 3 RepliesIDE :: Creating An Array Of A Structure Based On Existing Project?
May 1, 2009how to write the code for my project.I am to base my new project on an existing one(existing one has code that works 100%)and create an Array of a structure that bascially holds the information from a summary form AND the totals from an AddToOrder_Click event. If you are still with me)... I cant figure out what the code is for my structure and Array so that I STILL have a Summary Form but I have an array that shows when I click my PrintPreview. So an Array is basically a "space" that holds information, like my summary form except it doesnt show until I click PrintPreview right?
If I just wanted to show the table then my code belongs in the PrintDocument1_PrintPage to show the array but the actual structure code belongs in the Click_Event of my AddToOrder? Please Please understand I AM NOT asking for anyone to write my code, basically I am asking for some clarification on what exactly creating an array from a structure is and therefore determing where the structure is to be placed in my code..
Pass A Delegate Into A Constructor Of An Abstract Class From A Descendant's Constructor?
Feb 15, 2010I have an abstract class which requires a delegate to function. I pass the delegate into the constructor. Now that I have a non default constructor I need to call the abstract class's constructors from the concrete class which means that I need to use MyBase.New(...). I have included a quick example below.
Public MustInherit Class BaseClass
Public Delegate Sub WorkMethod()
Private _Work As WorkMethod
[code]....
I have tried to do this but I keep getting the following error: "Implicit reference to object under construction is not valid when calling another constructor".Can I not do what I am trying to do above? I initially had the delegate setup in its own setter method. But then I am creating a deceptive API because it does require a point to a method to work properly.
Why Is Constructor Call Valid Only As The First Statement In An Instance Constructor
Nov 2, 2009what's the rationale behind this limitation: Constructor call is valid only as the first statement in an instance constructor i want to pass an argument to my constructor which validates this argument and calls mybase.new according to this argument but it doesn't let me
example:
Public Class prob
Inherits System.ApplicationException
Public Sub New(ByVal problem As String, ByRef inner_exception As Exception)
[code]....
PDF - Takes A 1 Page Existing Pdf That Ispecify And Inserts That Into Another Existing Pdf?
Nov 11, 2010I need to make a program in vb that takes a 1 page existing pdf that i specify and inserts that into another existing pdf that i specify.
View 4 RepliesStructure Inside Another Structure Receives Null Reference Error?
Jan 5, 2012Module Module1
Public Structure structure1
Public TRANS() As structure2
End Structure
Public Structure structure2
Public X() As Integer
End Structure
End Module
Class Structure - Large Structure That Has Lots Of Properties ?
Jan 5, 2010I'm new to VB 2008 after having spent a long time with VB6, so I apologize if this is a stupid question. But I'd really like to have this straightened out.
Let's say I have a pretty large structure that has lots of properties.
Code:
Now say that I want an internal database with about 10 instances of this structure total, describing, say, 10 different products that a store sells. When these values are loaded from a database, they remain totally static. (However, they can be different each time a program loads)
Now say that I have a class. Each instance of this class is a type of that BaseProduct structure. Meaning, each instance of the class pertains to one of the 10 types of products that the store sells. However, this class has additional properties that pertain specifically to each instance, which are not static.
Code:
Now, the problem here is... If I have 200 different transactions, each one contains an instance of BaseProduct. BaseProduct is HUGE, and is largely redundant (only 10 types possible), so I think it's a little silly to include a whole copy of it with EVERY transaction. However, the Transaction class really needs information regarding the base product it pertains to. Is there a way to, instead of declaring a New BaseProduct in the Transaction class, to simply make one of the properties of the Transaction class a pointer to a BaseProduct variable?
In VB6, I would accomplish this by making a BaseProduct(10) array, and then giving each Transaction an ID number referring to an entry in that array. But in VB 2008, using class structure, this is impossible. I can't define the BaseProduct(10) array outside of a class in a namespace, and if I define it in the actual application's form, then the class loses modularity since it relies on the application that's using it.
Converting Structure Within Structure To Byte Array For Socket
Aug 29, 2009I am trying to communicate with an external device and i am trying to send a byte array to the external device via sockets but i am always getting a response the message size is too small so i am not sure what i have done wrong. Between the data type there should be no alignment present and all numbers are represented in little endian format. The char array is not null terminated as mentioned in the protocol specifications.
I have to send data based on a struct that embeds 2 other struct. So here's my vb.net code for the struct used to convert to byte array and the sending part.
Public Structure MESSAGETYPE_OIP_Login
Dim Header() As COMMANDHEADER
Dim UserName() As PSTRING
[Code]....
Invalid Structure Size When Marshalling C Structure To .NET
Apr 14, 2012I'm experiencing a problem with the following c-structure:
typedef struct tagTEXTUREPROP
{
DWORD dwSize;
[Code].....
The Marshal.SizeOf obviously calculates a size of 76 and it works with the DLL function, but it leaves me with some bad feelings.
VS 2008 Convert The XML Structure Into A Class Structure?
Apr 25, 2010I'm having a problem that's driving me crazy; I can't understand how to convert the XML structure into a class structure (that I want to use to hydrate a XML document).
The XML document looks like this:
xml
<?xml version="1.0" encoding="utf-8"?>
<artists xmlns:opensearch="http://a9.com/-/spec/opensearch/1.1/" xmlns="http://www.spotify.com/ns/music/1">
[code]....
Arraylist Of Structure Within Array Of Structure?
May 23, 2010I want to make a structure within a structure. Basically it will appear like this:
Structure ID
dim CardType as string
im CardCode as string
[code]......
Assign Array Of Structure To Another Of Same Structure?
Oct 12, 2010In Vb.net I am trying to assign an array of structure to another array of same structure[code]...
View 2 RepliesStructure With A Structure Array?
Sep 12, 2011I have two structrures
Public Structure PhoneScheduleEntries
Dim Count As UInteger
Dim PhoneSchedule() As PhoneScheduleEntry
End Structure
C# - Attribute's Constructor Run?
Jul 22, 2009When is it run? Does it run for each object to which I apply it, or just once? Can it do anything, or its actions are restricted?
View 3 RepliesCode The Latter Constructor?
Apr 1, 2010A project has a class (CAR Class) with the folloiwng details and the CARADMIN cLASS with the following details: The cardAdmin class has 2 constructor Public Sub New() & Public Sub New(ByVal rec As Rectangle) I dont know how to code the latter constructor..
cAR Class has this method/properties:
Public Class Car
Inherits HVSprite
Private fSoundFile As String
[code].....
How To Call A Constructor From Another
Jun 27, 2009I have a defualt constructor that has a object of a Database connectivity class:[code]therefore in theory i have to call the defualt constructor of Question from overloaded constructor. [code]How every in realitty is it possible to call the defautl constructor from the overloaded constructor
View 5 RepliesHow To Convert Constructor To C#
Aug 17, 2010Do not know how to convert Me.Base to C#Imports Microsoft.VisualBasic
Public Class ReplaceHTML
Inherits System.IO.Stream
Private Base As System.IO.Stream
[code].....
Pass Value Other Than From Constructor?
Jan 23, 2009how to pass value other than from constructor.
In my code....value are usually passed through constructor.
ie everything is declared in constructor and while executing, these values are defined in new object.
Static Constructor In .Net?
Feb 9, 2010I am rewriting a C# class in VB. The C# class has a static constructor in it:
static Class()
{
...
}
which, through the Call Stack, I found is called by the main window's InitializeComponent() method.Everywhere I've looked has told me that the corresponding static constructor in VB is just:Shared Sub New()
but this method is never invoked. Am I creating my VB static constructor right? Is it likely something else that has nothing to do with my static constructor?
<Attribute>: ParamArray In Constructor
Nov 10, 2010A former co-worker wrote a class in C# that was to be used as an attribute. I'm having to convert his work to VB (yeah, it's pointless and way more work than necessary, but management thinks it's a good idea). Unfortunately I'm having an issue because one of the main properties of the class is an ArrayList which is set with a ParamArray in the constructor. The class looks like this (note I've tried to abstract out the problem, so this is a simplified version of the class only)
<AttributeUsage(AttributeTargets.Field Or AttributeTargets.[Property])> _
Public Class LabelAttribute
Inherits Attribute
Public Sub New()
[CODE]........
In the first one, there is just the single label being added. No Problem. In the second one there are 2 different labels being added. Again, no problem. The third one, however, is a problem because it's assuming that the "Description", which is supposed to be the description is instead being interpreted as another label.
This wasn't a problem in C# because it could be set as follows:
[CODE].................
Of course this doesn't work in VB because optional parameters aren't referred to by name as they are in C#. As a stopgap I've changed the constructor to allow only a single label like this
CODE]..................
But that undermines some of what this class is meant to do. Does anyone know how, or even if I can get the same basic functionality to work in VB?
Think there must be a way to make the existing design work. Imagine this class was built into a library that I could not modify. Would I be forever forbidden from setting Description because of this design?
.NET Constructor With Parameters And Inheritance?
Jun 29, 2010Why VB.NET (vs C#) does not "inherit" the constructors with parameters?
Public Class StopLine
Inherits Microsoft.VisualBasic.PowerPacks.LineShape
Public Sub New()
MyBase.New()
[code]....
Assigning A Rectangle To This Constructor?
Oct 15, 2010Im having trouble with assigning a Rectangle to this constructor
fTrainAdmin = New TrainAdmin( )
C# - What Is Startup Form Constructor
Feb 16, 2012I need to put following code in the Constructor of my startup form.
JohnKenedy.BusinessSQLEXPRInstaller _ins = new JohnKenedy.BusinessSQLEXPRInstaller(" _ <Installation Display Name>", "localhost", "<New database instance name>", _
"<new database name>", "<database password>", "<database backup filename>");
if (_ins.IsDone == false) _ins.ShowDialog();
if (_ins.IsRestart == true) {
Application.Exit();
this.Close();
return;
}
But I really do not know what the Constructor is and how to access it?
C# - Why Are Not Allowed To Specify A Constructor In An Interface
Mar 27, 2009I know that you cannot specify a constructor in an interface in .Net, but why can we not?
It would be really useful for my current project to be able to specify that an 'engine' must be passed in with the constructor, but as I cant, I have to suffice with an XML comment on the class.
Calling Constructor When Using Generics
Mar 9, 2011I'm not sure if this is possible or not. I have a number of different classes that implement interface IBar, and have constructors that take a couple of values. Rather than create a bunch of almost identical method, is it possible to have a generic method that will create the appropriate constructor?
private function GetFoo(Of T)(byval p1, byval p2) as List(Of IBar)
dim list as new List(Of IBar)
dim foo as T
' a loop here for different values of x
foo = new T(x,p1)
list.Add(foo)
' end of loop
return list
end function
I get:
'New' cannot be used on a type parameter that does not have a 'New' constraint.
Constructor With Parameters And Inheritance?
Jun 23, 2011I searched quickly and not find an explicit answer at the following question:Why VB.NET (vs C#) does not "inherit" the constructors with parameters?
Public Class StopLine
Inherits Microsoft.VisualBasic.PowerPacks.LineShape
Public Sub New()
[code].....
Create Application For The BMP Constructor?
Feb 7, 2012I trying create Application for the BMP Constructor, I already write the code in C# but I can't translate it into VB.NET, because its require pointer, and as far as i know, there are no pointer function in vb.net @@ so how I can translate this:
FileStream fs = new FileStream(OJSPathBox.Text, FileMode.Open);
BinaryReader rdr = new BinaryReader(fs);
int width = 555; // its just for example
int height = 555; //its just for example
[code]....
ptr declaration is using Pointer and I throught, there are no unsafe in vb.net, how I can translate to vb.net language?
