So I've been doing some research on the singleton factory design pattern, and I am wondering if my example implementation is correct (warning I did get carried away creating animals):
[Code]...
What i really hate about it is if i have a control that custom paints then a transparent control within that control; it paints the transparent control as *button color* until it calls the transparent controls paint event again.... is there anyway to change the behavior of this so that it either paints the last draw over the control until it is actually repainted- or to @ least set a color other than button color?
you think it would @ least use the forms bg color instead - because it looks horrid when you have a black background with all of these near white boxes on it!
I am normally a c# programmer but am now working in VB for this one project when I use to set up a singleton class I would follow the Jon Skeet model
public sealed class Singleton
{
static Singleton instance = null;
static readonly object padlock = new object();
[code]....
I get StackTracker.Instance.Instance and it keeps going, while it is not the end of the world it looks bad.is there a way in VB to hide the second instance so the user can not recursively call Instance?
I am working on creating a customized UI composite control. This control would be a container to several other custom controls.As a first step, i am creating the container UI using a singleton pattern. This is because at any point in time only one isntance of this container is allowed to be created. This is fine.Now i want to practice interface based desgin. So i introduced a sinple interface calleD IdesignSurface which has two properties. I would like my singleton class to implement this interface,so i tried something like this and got an error saying "end of line
NotInheritable
Class DesignSurface
implements IDesignSurface
[code]......
Im trying to Implement the Singleton Pattern and im wondering if this is "Thread Safe" or if I am going to have to explicitly perform a SyncLock on the object instance? Example:
Public NotInheritable Class SingleTon
Private Shared _singleton As SingleTon
Private Sub New()
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I tried it both ways, using the SyncLock and without, just not sure which one to be using?
when should a trigger in your head go off signifying "Aha! I should use the factory pattern here!"? I find these moments will occur with many other design patterns, but never do I stop myself and think about this pattern.
View 6 RepliesI have a table, Users, with a related child table, UserSecurityGroups. In my GUI, the operator would select a user from a list. The program would retrieve the user record and allow the operator to edit the user data in one form. The operator could also edit the UserSecurityGroups of this user on another form.
I am considering using a singleton class for user instance retrieval and persistance back to the database. If this is a good practice, I want to use this with many other tables in my DB. My question is: Is this a good practice? What pitfalls am I missing? What would you recommend as an alternative? Would your recommendation change since I also have tables with three or four levels of relations (as opposed to two in the example above)?
Here is my proposed code:
Imports System.Data.Linq
Public Class UserConduit
Implements IDisposable
[code]....
I'd like to expose some functionality via a WCF service. I can configure WCF to instantiate a class per-request but am unsure how I can get a reference to a communal singleton if I were to have some functionality to store a list of calls to a method (call it LogMethod) via WCF in memory and return that list when the GetLogs method is called
I'm aware I could use a database/the file system to pass this data back an forth but in many cases, that seems to be overkill. Edit: It seems that nobody has a clear answer - I can't believe this is complex. Am I missing something obvious?
I am a budding MCTS so I am not a 100% sure of whether I am correct in this instance.I am looking through a windows forms application created by a developer who has left our company some time ago. Within the code I have found a custom form derived from the standard form baseclass which explicity implements IDisposable.The custom form does not call any COM object or do any file IO operations and has only one database call which is closed and disposed off in the method that calls it. However within the code of the form there is the following,[code].....
Looking at this am I right in thinking that this should be removed including the implements IDisposable line at the top of the form since,
1. The listeners collection will go out of scope when the form does as the collection only references listener objects (which do not implement IDisposable).
2. The controls do not explicitly need disposing, since when the form goes out of scope this will be done anyway.
I have developed a C++ program code .Now, I want to access this code in VB.net .
View 2 RepliesI have written a base class from which I wish to derive several child classes (in this case Windows Form classes), and I'm using a Factory pattern in order to maintain a collection of the child instances, so that a form can only have one instance per primary key value. (sort of a mash-up of Factory and Singleton patterns.)
I'm using the following code in the base form class[code]...
I need to implement the IBindableComponent to the the following code:
Public Class InfragisticsToolStripBindableButton
Inherits Infragistics.Win.UltraWinToolbars.ButtonTool
Implements IBindableComponent
[CODE]...
1 problem: Warning: event 'Disposed' conflicts with property 'Disposed' in the base class 'DisposableObject' and should be declared 'Shadows'
2 problem: Error: Class 'InfragisticsToolStripBindableButton' must implement 'Property Site As ISite' for interface 'System.ComponentModel.IComponent'. Implementing property must have matching 'ReadOnly' or 'WriteOnly' specifiers.
Why should I implement "IComponent" if I implement "IBindableComponent"?
3 problem: How should I override "Dispose", if it's already implemented in the base class, but is not virtual apparently.
I'm sorting a collection of type "Document" (usually around 100k records). Sorting usually takes around 4-5 seconds, and I'm wondering if there's a way to speed up sorting by modifying my "DocumentComparer" class which implements IComparer(Of Document). Since the Compare() method would be called hundreds of thousands of times, are there any performance improvements that could be made here that I've overlooked?
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I need to implement the IBindableComponent to the the following code:
Public Class InfragisticsToolStripBindableButton
Inherits Infragistics.Win.UltraWinToolbars.ButtonTool
Implements IBindableComponent
[code].....
After some research, I've decided to use the Liang-Barsky line clipping algorithm in my 2D game. Google did not deliver on any VB.NET implementations of this algorithm but plenty C/++ ones. Therefore, as I have knowledge in C++, decided to port one found on Skytopia over to VB.Net. Unfortunately, it does not work with:
Public Class PhysicsObject
Public Function CollideRay(ByVal p0 As Point, ByVal p1 As Point, ByRef clip0 As Point, ByRef clip1 As Point) As Boolean
Dim t0 As Double = 0.0
Dim t1 As Double = 1.0
[code]....
However, the CollideRay method fails on its 3rd edge iteration (edge = 3), r < t0, therefore the function returns false.
I created an array sorter to sort arrays like in Win Explorer in a DNN module. As in the answer to a preview question: Sorting an array of folder names like Windows Explorer (Numerically and Alphabetically) - VB.NET
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The problems:
I can't use string.Format, I have C style format strings;I can't call the native printf (no P/Invoke);I can't use http://www.codeproject.com/KB/printing/PrintfImplementationinCS.aspx because of the license, I need something GPL-compatible.Is there a free implementation of printf/sprintf for the .net framework? Other than the above link, I couldn't find anything.
I cooked up a sprintf function that supports basic format strings, you can find it here: [URL].. I'll try to make it a complete implementation if I can.
I need to use some functions from a DLL written in C++. Problem is when I try to use those functions in VB (Visual Studio). The only way I get to pass the debugger without errors is if I use the VariantType type, but I get all screwed up values. Can anyone tell me how can I "translate" the use of char [6] into VB from C++? My problem when Implementing is with the variable INFO, the content comes back after execution with errors..This is the original code from the DLL Manual:
Code:
Int Get_Info(A Handle, char *IPAddr, InfoType *Info)
where the parameters:
A [IN] Handle.
IPAddr [IN] IP address
[code]....
I am trying to use some C# code that expands on the GridView functionality in a VB.NET project. The code I'm using is from here.
In the C# code there is an event definition for GroupHeader [code]...
I implemented IDisposable into one of my classes, but don't know if I did it correctly. Can someone tell me what will be cleared from memory and what will remain after calling .Dispose on an instance of this class? [Code]
View 5 RepliesWhat is the diference of using interfaces like ...I have an interface
Public Interface IProDataSource
Function read() As Integer
End Interface[co]....de
The only difference I have notice is that if the method is declare private it will be visible using the first approach only.
I am working on an application which uses multiple threads to work on number of tasks and the parent application receives the output of the task,later to be written to files, currently I am using arraylist to append output to, but that happens to be slow when removing items from queue.I was thinking to convert arraylist part to linkedlist for optimized reads and clears,if linkedList Implementation of .Net is threadsafe or even using arraylist was threadsafe?
View 3 RepliesThe middleware that manages talk between the mainframe and our app is blowing up randomly. It's a "such and such attempted to read/write protected memory..." error.The vendor is saying there we must be running some unmanaged code (I feel they're trying to worm out of it). I know VB's entirely managed, but does anyone know about the server portion of AJAX? Is there any server side javascript stuff that occurs before it actually gets into the .NET framework?
View 1 RepliesI have been reading about design patterns and application architecture and im told that I should program to an interface instead of implementation. This i understand. So I figured I would start with something small. Never programmed with an interface before. So I want to create an encryption program that will allow the user to select which method to encrypt it with, AES, DPAPI, etc. I started designing the Interface but I am unsure if I am doing this right. [Code] Also, when it comes to the DPAPI implementation, how is the client supposed to supply the Protection Scope? I didn't think this should be in the interface as it only applys to the DPAPI.
View 1 RepliesI basically want to remove the formula from the cells but want to retain the calculated values.
SO, I implemented it easily and it works great but REALLY SLOW. (About 2 mins for 1800 cells)
I have : Dim col As Excel.Range = getRange()For Each cell In col cell.Value = cell.Value Next
I tried to do this to the first cell and then autofill the rest, but that copied the value of 1st cell to the rest of the cells in column.
Can anyone point me towards a complete scenario using MSTest,vb.net, with or without mocks,MVP (supervising controller)
View 1 RepliesI need to create a monitoring mechanism using SNMP (in .Net). I think we'll be using an nsoftware component to handle most of the work. It appears we must use 'traps' to communicate from the agent to the server. We'll have a number of different traps and various information detailing each trap. What is the best way to implement custom traps? That is, what is the best way to not only send a trap, but also send the information describing the trap to our 'snmp manager'? I think this is done through "variable bindings". To use "variable bindings" do we need to create our own "enterprise number" and use an "enterpriseSpecific" trap? Should we implement our own, custom MIBs or can we just send the data we need with the trap (via variable bindings)?
View 2 RepliesIn Flash 10 there are methods that require that they are triggered from user-initiated actions like button click, keyboard up/down keys, etc.Is it possible to implement this behaviour in .NET? For example, if we have this subroutine:
void SomeMethod() {
// Here some stuff
}
how to check inside it whether the method was called from a mouse click event handler?Also we can think of this methods like the protected functions in World of Warcraft.
EDIT: Looks like this behaviour is implemented in Silverlight — we can popup file dialogs (open, save) ONLY by mouse click or other user-initiated action, otherwise a SecurityException will be thrown. I want to achieve this bevaviour but in my case it's not a file dialog but our own methods.
just wondering if we could change the implementation functino of IDisposable.Dispose to a private. because the default i've got something like this:
[Code]...
Protected Overridable Sub Dispose(ByVal disposing As Boolean) or could i take away the the Protected Overridable and replace it with a Private access modifier?
This may seem like an obvious answer, but I can't seem to find an answer. I have this code in VB.NET[code]...
The problem with this is that in C#, it would seem you have to name the function the same as the interface function you are implementing. How can I call this method EncryptionVB instead of Encryption, but still implement the Encryption property?