a debate has been sparked here about the use of the strategy pattern in my classes.
Basically, I have a 'Shape' object that is an interface 'IShape'. We have 'Circle', 'Rectangle' and 'Elongated' that are the concrete classes that must implement the IShape interface.
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is it possible to implement strategy pattern with different parameters in VB.net? For example I have the following code:
Public Interface InterfaceDataManipulation
Sub updateMyData()
End Interface
How to implemente updateMyData in the class that implements above interface class with different parameter,for example in class x :
Public Class X
Implements InterfaceDataManipulation
Public Sub updateMyData(ByVal x as String)[code]......
But the IDE raises an error "class x must implement updateMyData on interface InterfaceDataManipulation"
I've implemented the Event Based Async Pattern for the first time in a relatively complex class. I'm having some doubts about if I've done it as it should be done, and if there are no better approaches. One of the things that make me frown the most is how I'm currently handling all the cross thread events. This class contains a decent amount of events, about 20. What I've done is created a dictionary in which I have a list of callbacks, one for each event. The keys are a value of an enum containing all keys I created. In the underneath line, eventDelegates is the dictionary, and delegates is the enum.
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I'm seeing a strange build bug a lot. Sometimes after typing some code we receive the following build error.
Class 'clsX' must implement 'Event PropertyChanged(sender As Object, e As PropertyChangedEventArgs)' for interface System.ComponentModel.INotifyPropertyChanged'.
And
'PropertyChanged' cannot implement 'PropertyChanged' because there is no matching event on interface 'System.ComponentModel.INotifyPropertyChanged'.
Those error should never go together! Usually we can just ignore the exception and build the solution but often enough this bug stops our build. (this happens a lot using Edit and Continue which is annoying)Removing the PropertyChanged event and retyping the same code! sometimes fixes this.We're using a code generator that causes this error to surface but just editing some files manually triggers this exception too. This error occur's on multiple machines using various setups.
I have a base class which must be overriden. This base class sits in one dll shared by all. The derived classes will each be in their own dll such that the addition of a new derived class can be done by distributing a new dll. The set of dlls, and therefore the set of derived classes, will be discovered by the main program on startup. That's all pretty straightforward. The problem is that the main program needs to be able to query a database to figure out which type of derived class it needs, then create a class of that type. Naturally, it can't know which types will be available ahead of time because even I don't know that. The program has to be dynamically extensible.The obvious way to do this is to have an interface in the dll that is implemented by a class with a default constructor. The sole purpose of that class would be to return an object of the type (one of the derived types) defined in that dll. The derived types can't really be this class, because they can't have a default constructor since the base class doesn't have a default constructor, and the derived class can't make up the arguments that the base class constructor needs.
So basically, each dll that houses a derived class would also house a simple class that implemented an interface for the sole purpose of creating that particular derived class. The main program would examine the dll to find a class that implemented the interface, and once it found one, it could ask it what type of class it created, or it could ask it to create an instance of that class. It seems like there ought to be an easier way to dynamically add new classes to the project. It seems like the derived class ought to be able to tell the main project what type it was. This could be done, except that the derived class would have to exist before any of its methods could be called unless the methods were shared. Since you can't have a shared method in an interface, the interface itself would make no sense at that point, in which case I would need to discover whether the class in the dll derived from the base class in the second dll, just to figure out whether or not I wanted to create it. That's getting convoluted by now, so I guess I'll leave it there. The basic point is that the base class is known to the main program from a common dll. The number and types of derived classes can't be known at this time, so the program has to be able to discover them dynamically. Each derived class will sit in its own dll (or there could be more than one in a dll), and has to be discovered, and instances created, as needed, by the main program.
I've noticed that in C# XML comments and code comments can have different colors by changing the settings in Tools > Options > Environment > Fonts and Colors > Display Items:
- Comment: controls code comments XML comment: controls XML comments
This works well in C# <summary>This XML comment is green</summary>
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I have a MustInherit class, let's call it BaseClass, with a bunch of MustOverride ReadOnly properties. The user is supposed to inherit this class and override the properties, returning appropriate values.To help the user decide which property does what, I have included XML comments for each property, so the BaseClass looks like this [code]I now want to enable the user to inherit this class (DerivedClass1) instead, so that he can, for example, override only the Name property, and leave the other properties untouched. This way, he can create a slight modification to one of the default classes, instead of having to rewrite it completely (in reality, there are loads more properties). There are no XML comments, because they are in the BaseClass, and not in the DerivedClass1, which is the class I'm inheriting. In other words: the XML comments are not 'inherited'.Do I really have to copy/paste all the XML comments from the BaseClass and put them in the DerivedClass1 too? Or can I somehow tell the DerivedClass1 to use the XML comments from its base class?
View 1 Replieseverytime i try the space then underscore + enter it doesnt work and it lights up red edit - like for example this is a comment:'you must add such and such to this variable and then you must declare it' say i have that for a comment and i want to break the comment after variable. when i do this 'you must add such and such to this variable
View 2 RepliesI am getting the following compilation errors from Microsoft Visual Basic 2010 Express on the first line of my code:
Error 1 Newline in constant C: cdotnetdevsrcvbmain estHelper.vb 1 1 Component Sources
Error 2 Too many characters in character literal C: cdotnetdevsrcvbmainRtestHelper.vb 1 1 Component Sources
The first line of my code is simply:
' Copyright 2011
It is generating the same compilation error for all my comments. Does anyone know why MS VB Express 2010 is acting this weird? Comments in visual basic are supposed to start with a single apostrophe so I don't understand this weird behavior.
I am refining my VS2010 control renderers and I'm working on the TabControl at the moment. If you take a screenshot of the VS2010 IDE and zoom in on the background of the TabControl (where there are no tabs), then you might see that it consists of a pattern of dots with a slightly different color than the surrounding background. I am trying to draw these dots (yes, I'm going for perfection), but I cannot find a brush that allows me to do this.I am pretty sure I'd have to use a HatchBrush with the right HatchStyle, but I cannot find a matching style.Here is a screenshot showing:
1. The VS2010 background I'm trying to draw (higher contrast and brightness otherwise it's hardly visible),
2. The HatchStyle that is closest to this (DottedDiamond)
3. Why this HatchStyle is not correct (it's missing dots where the green dots are, which I photoshopped in).
Now of course I'm going to have to draw the pattern twice (there are two patterns, offset by 1 pixel, with a slightly different color), but the more pressing problem is the green dots seen in the third image. They aren't there with the DottedDiamond style, and no other style (I think I've tried them all, but hey I might have missed some..) produces a better output.
I am trying to parse a string that contains known and unknown characters.here is an example:
[1]Tue Jun 19 17:14:15 2012, 48:17:4C:00:00:74, 4.8, 5449,816324, 26, 31397, 160855, 30775030, 29962782, 812248, 2394476, 71619, -44, -67, 46, -60, 51, 0, 86468, 2547055, 4687358, 44278, 4593, 65076, 65191, 65106, 65166, 65108, 64552, 64572, 64512, 5.1, 2548502, 4690906, 520, 0, 0, 0, 36, 2412
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The known part is the [0] or [1] or whatever number in the brankets.the unknown part is the rest of the message.So if i have this string i want to cut it to smaller substrings that start with [ and end before the next [ .To make it more tough, sometimes, before the next [ there is another message that comes like: Jun 19 17:13:40 2012 timestamp And after that it continues with the next [
Has anyone ever used VB to analyze data to find patterns? I would like to analyze several hundred sequential data points to look for a fairly uniform "up-down" pattern, very similar to a square wave.
View 3 Replieshave a 1mb file, should get the pattern from it
pattern should be like this
6numbers + 10&FF + 6numbers
in the hex binary editor it looks like this
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I need an extremely simple regex pattern that matches anything within square brackets [].
Example:
This is a [test] text with [some] [examples].Required results: [test], [some], [examples].I don't want to get rid of the brackets, they should be included in the result (that should make it easier, right?)
If possible I'd like to exlude results that have whitespace in them, so things like [this string] should not be matched. If that gets too hard (probably not, but hey I can't even manage this :S) then I don't really mind, I can always check if the result contains whitespace myself.
I tried a lot of examples I could find online and ones that I could think of myself but none work. Note: I've been testing with the Visual Studio Find dialog (checking to use regular expressions obviously), maybe that's where the problem lies, because I don't really understand why some of these don't work...
Anyway, first thing I tried was simple: match the two brackets and one or more characters in between (that should be a +, right?)
It seems up until now I've never used Regex, nor even heard of it. But once I did I realized how extremely useful this is. Having said, it's been 2 days since I've began looking into constructing my own patterns. My most recent being for decimals. Is the pattern I provided below "proper"? and are there also any improvements I could be making for a more efficient patter, which would minimize any possibility of a loophole? [code] So for my use, this is doing what it's supposed to being doing under every test I can through at it. But do mind the 0. and .0, I have a function to normalize these as they are proper, I just pad the left and right accordingly. I found most regex questions asked here..and yes I am doing this in vb.net so it fits. If not, then feel free to move this post somewhere else better suited for the topic of discussion.
View 12 RepliesWould it be a good idea to start converting forms into .NET one at a time which you would then invoke from the VB6 app via COM-interop.This way, by the end of the process you would just convert the 'shell' of the VB6 application into a new .NET app, and all your forms are ready to go in .NET.
View 5 RepliesI have inherited a .NET 4 VS2010 solution consisting of a WinForms app and a web service. I don't have access to a server that's running a copy of the web service but I have to run, debug, upgrade and test the project that accesses the web service as well as the web service code.Later, I also want to quickly switch between a deployed web service and the code in my local projectWhat's the best strategy for changing the projects so I can make changes to both projects, test locally, deploy the web service then test against that? If I find issues, I want to switch back to "local" mode to debug.
View 2 RepliesI developed app which accepts user responses. I created secondary labels which I envisioned as larger "tool tips" which prompt the user. ("prompts")As the user inputs to either combo box or text box, the label should go invisible and a "prompt" for the next input should go visible.I am trying to use Selected Index Changed,Leave, or LostFocus events to accomplish the visible invisible change.Is that the most effficient way to accomplish my functionality? A twist I would like to incorporate: the purpose of the "prompts" is to guide an unsophisticated user through the app the first couple times.After familiarity is acheived the "prompts" can be annoying.My strategy is to allow user to turn off the "prompts" by a check box.Then my conditionals will test the checkbox. checked property and either show the "prompts" or not based on the test. [code]
View 7 RepliesWe have a asp.Net vb.net 2008 project on tfs2010. The project has one main branch and for any release we create a new feature branch which is finally deployed. Post production deployment we merge back the branch back into main branch.We are now also adding a db project to manage our SQL too. Question is how to version control the differential scripts. The db project contains all create scripts which is fine if we had to deploy thep project from scratch but the project is already live. So now any new release or hotfix would normally contain alter or change script practically.
View 1 RepliesI'm about to start a new project and want some advice on how to implement.I need a web application which contains a booking module for reserving timeslots, and a time management module which will enable employees to clock in / clock out.
If I am writing an update to the time managment module, I don't want to disrupt the booking engine availability by releasing a new solution containing both modules.to make things more difficult, there is some shared functionality like common users, roles and security.Here's a suggestion I've gotten, which sounds a bit cruddy, but may be functional.Write a 'container' web application which consists of basically a frame, and authentication / security features. This then has links which, will load the 2 independantly built and released web applications into the frame.I can see that say, if I wanted to update the time management module,
I'm trying to bind a WinForms TreeView control to some user-defined objects. In particular, I'd like to bind aTreeNode.Text property to myObject.Name. My strategy is to create xTreeNode, a subclass of TreeNode, add a DataBindings collection, and expose its Text property.
This would allow me to write some code like this:
Dim oBinding as Binding
Dim bs as New BindingSource
bs.DataSource = myObj
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Im a new in this VS2008. But i have some foundation of programming in VB6.0. So im planning to create this application using VB since im familiar in that language.I downloaded a Visual Studio 2008 and SP1 - now on its 90-day trial, and planning to buy the full version depending if it will meet my needs. I just read afterwards the conditions and how to buy it. I hope its free shipping and credit card is acceptable.^^
I need to make an application something like a reporting system, my plan application is a client-server application. Currently im reading the How to topics and some walkthroughs so far so good. Now here are some sort of details and target need to fulfill.
1. An interface from client that will input the data from the multiple-user , including images and these data will be saved in database/table remote server (center database server) LAN.
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we changed the mapping from the table per concrete class to the subclass strategy and now the UnitTests fail, but I cannot recognize why.There's one base class Article and a child one SemifinishedArticle with no specific properties.
Article.hbm.xml:
<?xml version="1.0" encoding="utf-8" ?>
<ibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
[code].....
I have a usercontrol with a picturebox and a few buttons related to it, such as LoadFromFile, Paste and Zoom (that last one pops up a new form). Is there a way to override the basic Enabled property of the usercontrol so that I can keep the Zoom button active all the time, while turning off the other buttons?
I realize there are 2 "obvious" replies. don't do Enabled=False, create a custom method. do everything in the one form, not a usercontrol, so you can pick and choose disabling. Both are less than ideal, given that I'm putting this control into a couple of existing forms, so I'd like to work around how those forms already behave. So is there a way to override the behavior of my usercontrol when it gets disabled? What would be my best strategy?
I have to compare two columns in two different Excel sheets and delete the duplicates. I have come up with several strategies that work, but I am searching for the most efficient way to do this. At first, I was sorting the columns and looping through them in the manner of a sequential update and deleting when the cell values were equal. But I discovered here an article by Mike Rosenblum that explained that it is much more efficient to stick the columns into an array and iterate them from there. So I was able to do that. There was a complication in that once I had deleted a row, then the array and the spreadsheet were out of sync. So I had to compensate by incrementing a variable each time a row was deleted, and subtracting this variable from the array index to calculate the row to be deleted in the spreadsheet.
So now I am wondering whether there is a better strategy. I thought that if I could merely hide the rows to be deleted and then find a way to delete all hidden rows at once after the loop was over, then this would eliminate the problem of the array and the spreadsheet getting out of sync and would make the code easier to understand. I thought of putting the row numbers of the duplicates into another array and deleting the rows after the comparing loop. But this creates the same problem of having to compensate the row numbers in the array.
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The garbage collector in .NET moves objects, so the object's address is not stable. How is Object's GetHashCode() method implemented?
I found the line in a program that references UrlNormalizerUtil.UrlNormalizer to validate a url. It calls it from a GeneralPurposeUtilities file which is added to the project properties in references as a .dll file.
My question is: where does this file come from? Is is self coded or from some library? how else can the UrlNormalizer be implemented?
I have an Entity class which Implements IWeightable:
Public Interface IWeightable
Property WeightState As WeightState
End Interface
I have a WeightCalculator class:
Public Class WeightsCalculator
Public Sub New(...)
..
End Sub
Why can I not do wc.Calculate(entities)? I receive:
Unable to cast object of type
'System.Collections.Generic.List1[mynameSpace.Entity]'
to type
'System.Collections.Generic.IList1[myNamespace.IWeightable]'.
If Entity implements IWeightable why is this not possible?
I saw the question posed here: Have I implemented Equals()/GetHashCode() correctly? but my c# is not as strong, and I am unfimiliar with IEquatable enough that I would like to see this in VB.NET if possible please.My example code (The class will eventually use INotifyPropertyChanged when I get there):[code]
View 2 RepliesI've boxed in red. The class displayed here does implement INotifyPropertyChanged, but the VB compiler seems to think that the PropertyChanged event as declared does not match the signature of INotifyPropertyChanged.PropertyChanged.Here I've selected the offending line of code. Between this and the next screenshot I literally just cut and paste the exact same line back into the file (i.e., I hit Ctrl + X followed by Ctrl + V).I have this happen sometimes, particularly with the INotifyPropertyChanged interface in my experience but I have no idea if the problem is limited to that single interface (which would seem bizarre) or not.Let's say I have some code set up like this. There's an interface with a single event. A class implements that interface. It includes the event. [code] Every now and then, when I build my project, the compiler will suddenly start acting like the above code is broken. It will report that the Person class does not implement INotifyPropertyChanged because it doesn't have a PropertyChanged event; or it will say the PropertyChanged event can't implement INotifyPropertyChanged.PropertyChanged because their signatures don't match.This is weird enough as it is, but here's the weirdest part: if I just cut out the line starting with Event PropertyChanged and then paste it back in, the error goes away. The project builds.
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