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  • VB to C# conversion incongruency with lambdas

    - by Jason
    I have a bit of code that I have been tasked with converting to C# from VB. A snippet of mine seems like it cannot be converted from one to the other, and if so, I just don't know how to do it and am getting a little frustrated. Here's some background: OrderForm is an abstract class, inherited by Invoice (and also PurchaseOrder). The following VB snippet works correctly: Dim Invs As List(Of OrderForm) = GetForms(theOrder.OrderID) .... Dim inv As Invoice = Invs.Find( Function(someInv As Invoice) thePO.SubPONumber = someInv.SubInvoiceNumber) In C#, the best I came to converting this is: List<OrderForm> Invs = GetForms(theOrder.OrderID); .... Invoice inv = Invs.Find( (Invoice someInv) => thePO.SubPONumber == someInv.SubInvoiceNumber); However, I get the following error when I do this: Cannot convert lambda expression to delegate type 'System.Predicate' because the parameter types do not match the delegate parameter types Is there any way to fix this without restructuring my whole codebase?

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  • How do I implement a custom Brush in WPF?

    - by MojoFilter
    Where can I find out enough info about how Brushes work to implement my own System.Windows.Media.Brush? I can handle all of the freezable baggage, but it's not really obvious what I need to override to get it to work. Yeah, so I didn't mean that I want to use a predefined brush. I want to extend System.Windows.Media.Brush, which is an abstract class. This is all purely for my own edification. I'm not even sure what kind of brush I could make. I was just trying to learn how brushes work. As in: public AwesomeBrush : Brush { protected override Freezable CreateInstanceCore() { return new AwesomeBrush(); } ... // concrete brush stuff }

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  • Referring to the type of an inner class in Scala

    - by saucisson
    The following code tries to mimic Polymorphic Embedding of DSLs: rather than giving the behavior in Inner, it is encoded in the useInner method of its enclosing class. I added the enclosing method so that user has only to keep a reference to Inner instances, but can always get their enclosing instance. By doing this, all Inner instances from a specific Outer instance are bound to only one behavior (but it is wanted here). abstract class Outer { sealed class Inner { def enclosing = Outer.this } def useInner(x:Inner) : Boolean } def toBoolean(x:Outer#Inner) : Boolean = x.enclosing.useInner(x) It does not compile and scala 2.8 complains about: type mismatch; found: sandbox.Outer#Inner required: _81.Inner where val _81:sandbox.Outer From Programming Scala: Nested classes and A Tour of Scala: Inner Classes, it seems to me that the problem is that useInnerexpects as argument an Inner instance from a specific Outer instance. What is the true explanation and how to solve this problem ?

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  • identifying the type

    - by Gokul
    Hi, In my application, there is a inheritance hierarchy in which only the classes that are at the end of the inheritance chain are non-abstract classes. Also there is some usage of boost::variant. I want to write a function which takes a pointer and a Type and says whether the object belongs to that type. For example template< typename Type, bool TypeisAbstract, typename ptrType > bool checkType( ptrType* t) { return ( typeid(*t) == typeid(Type) ); } template< typename Type, typename ptrType > bool checkType<Type, true, ptrType>( ptrType* t) { return ( dynamic_cast<Type*>(t) != NULL ); } Now if there is a boost variant, i want to find out whether the boost variant stores that particular type. Can someone help me with that? Thanks, Gokul.

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  • Is it possible to overwrite a static method in parent class?

    - by MartinDenny2069
    I have a static method defined in a base class, I want to overwrite this method in its child class, is it possible? I tried this but it did not work as I expected. When I created an instance of class B and invoke its callMe() method, the static foo() method in class A is invoked. public abstract class A { public static void foo() { System.out.println("I am base class"); } public void callMe() { foo(); } } Public class B { public static void foo() { System.out.println("I am child class"); } }

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  • NHibernate with or without Repository

    - by Groo
    There are several similar questions on this matter, by I still haven't found enough reasons to decide which way to go. The real question is, is it reasonable to abstract the NHibernate using a Repository pattern, or not? It seems that the only reason behind abstracting it is to leave yourself an option to replace NHibernate with a different ORM if needed. But creating repositories and abstracting queries seems like adding yet another layer, and doing much of the plumbing by hand. One option is to use expose IQueryable<T> to the business layer and use LINQ, but from my experience LINQ support is still not fully implemented in NHibernate (queries simply don't always work as expected, and I hate spending time on debugging a framework). Although referencing NHibernate in my business layer hurts my eyes, it is supposed to be an abstraction of data access by itself, right? What are you opinions on this?

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  • ASP.NET MVC IoC usability

    - by Andrew Florko
    Hello everybody, How often do you use IoC for controllers/DAL in real projects? IoC allows to abstract application from concrete implementation with additional layer of interfaces that should be implemented. But how often concrete implementation changes? Should we really have to do job twice adding method to interface then the implementation if implementation hardly will ever be changed? I took part in about 10 asp.net projects and DAL (ORM-like and not) was never rewritten completely. Watching lots of videos I clearly understand that IoC "is cool" and the really nice way to program, but does it really needed?

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  • jquery tabs with form help

    - by sico87
    Hello, I am implementing jQuery tabs on mysite, one of the tabs holds a form and this is my problem, the form is loaded in via ajax as it is used multiple time throughout the site. My issue is that when the form is submitted the page leaves the tabbed area, whereas I need to stay within the tabbed system. Below is the code I am using TABS HTML <div id="tabs"> <ul> <li><a href="#tabs-1">Active Categories</a></li> <li><a href="#tabs-2">De-activated Categories</a></li> <li><a href="<?=base_url();?>admin/addCategory">Add A New Category</a></li> </ul> FORM MARKUP <div id="contact_form"> <?php // open the form echo form_open(base_url().'admin/addCategory'); // categoryTitle echo form_label('Category Name', 'categoryTitle'); echo form_error('categoryTitle'); $data = array( 'name' => 'categoryTitle', 'id' => 'categoryTitle', 'value' => $categoryTitle, ); echo form_input($data); // categoryAbstract $data = array( 'name' => 'categoryAbstract', 'id' => 'categoryAbstract wysiwyg', 'value' => $categoryAbstract, ); echo form_label('Category Abstract', 'categoryAbstract'); echo form_error('categoryAbstract'); echo form_textarea($data); // categorySlug $data = array( 'name' => 'categorySlug', 'id' => 'categorySlug', 'value' => $categorySlug, ); echo form_label('Category Slug', 'categorySlug'); echo form_error('categorySlug'); echo form_input($data); // categoryIsSpecial /*$data = array( 'name' => 'categoryIsSpecial', 'id' => 'categoryIsSpecial', 'value' => '1', 'checked' => $checkedSpecial, ); echo form_label('Is Category Special?', 'categoryIsSpecial'); echo form_error('categoryIsSpecial'); echo form_checkbox($data);*/ // categoryOnline $data = array( 'name' => 'categoryOnline', 'id' => 'categoryOnline', 'value' => '1', 'checked' => $checkedOnline, ); echo form_label('Online?', 'categoryOnline'); echo form_checkbox($data); echo form_error('categoryOnline'); //hidden field check if we are adding or editing echo form_hidden('edit', $edit); echo form_hidden('categoryId', $categoryId); // categorySubmit $data = array('class' => 'submit', 'id' => 'submit', 'value'=>'Submit', 'name' => 'categorySubmit'); echo form_submit($data); echo form_close(); ?> </div> FORM PROCESS function saveCategory() { $data = array(); // we need to set the what element the form errors get displayed in $this->form_validation->set_error_delimiters('<div class="formError">', '</div>'); // we need to estabilsh some rules so the form can be submitted without error, // or if there is error then the form needs show errors. $config = array( array( 'field' => 'categoryTitle', 'label' => 'Category title', 'rules' => 'required|trim|max_length[25]|xss_clean' ), array( 'field' => 'categoryAbstract', 'label' => 'Category abstract', 'rules' => 'required|trim|max_length[150]|xss_clean' ), array( 'field' => 'categorySlug', 'label' => 'Category slug', 'rules' => 'required|trim|alpha|max_length[25]|xss_clean' ), /*array( 'field' => 'categoryIsSpecial', 'label' => 'Special category', 'rules' => 'trim|xss_clean' ),*/ array( 'field' => 'categoryOnline', 'label' => 'Category online', 'rules' => 'trim|xss_clean' ) ); $this->form_validation->set_rules($config); // with the validation rules set we can no run the validation rules over the form // if any the validation returns false then the error messages will be returned to the view // in the delimiters that we set further up the page. if($this->form_validation->run() == FALSE) { // we should reload the form $this->load->view('admin/add_category'); } }

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  • ActionScript: Type coercion problem with BlazeDS/AMF and class interfaces

    - by mike
    Hi, I've got a problem with type coercion in a Java/Hibernate/BlazeDS/Flex-Setup. First of all, my classes look like this: --- JAVA --- Interface I (Abstract) Class A implements I Class B extends A --- ActionScript --- Interface I Class A implements I Class B extends A I got RemoteClass-Meta-Tags in all ActionScript-Classes/Interfaces I, A and B. Package structure and Class/Interface names are exactly the same. Now here's the problem: My Java Service successfully retrieves objects of class B from my database via Hibernate. I got another class C which has a member property of interface type I, so it should be possible to assign an object of type B. But for some reason i get the following error message: TypeError: Error #1034: cannot convert Object@28b44a89 to package.name.I I checked the Java object type in the service and it is of type B and seems to be totally fine. Why can't the object of type B be assigned to a member variable of type I? This is driving me nuts. Thanks in advance.

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  • Programmatically access document properties

    - by ngm
    Is there a way in which I can programmatically access the document properties of a Word 2007 document? I am open to using any language for this, but ideally it might be via a PowerShell script. My overall aim is to traverse the documents somewhere on a filesystem, parse some document properties from these documents, and then collate all of these properties back together into a new Word document. (I essentially want to automatically create a document which is a list of all documents beneath a certain folder of the filesystem; and this list would contain such things as the Title, Abstract and Author document properties; the CreateDate field; etc. for each document)

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  • Fastest method for SQL Server inserts, updates, selects from C# ASP.Net 2.0+

    - by Ian
    Hi All, long time listener, first time caller. I use SPs and this isn't an SP vs code-behind "Build your SQL command" question. I'm looking for a high-throughput method for a backend app that handles many small transactions. I use SQLDataReader for most of the returns since forward only works in most cases for me. I've seen it done many ways, and used most of them myself. Methods that define and accept the stored procedure parameters as parameters themselves and build using cmd.Parameters.Add (with or without specifying the DB value type and/or length) Assembling your SP params and their values into an array or hashtable, then passing to a more abstract method that parses the collection and then runs cmd.Parameters.Add Classes that represent tables, initializing the class upon need, setting the public properties that represent the table fields, and calling methods like Save, Load, etc I'm sure there are others I've seen but can't think of at the moment as well. I'm open to all suggestions.

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  • In ASP.NET MVC (3.0/Razor), do you prefer multiple views, or conditionals within views? Why?

    - by Chad
    For my new web app, I'm debating on using multiple views, or conditionals within views. An example scenario would be showing different info to users who are authenticated vs non-authenticated. This could be handled a couple ways. In the controller, check IsAuthenticated and return a view based on that In the view, check IsAuthenticated and show blocks of info based on that Pros of multiple views: Smaller, less complicated view - next to no logic in the view Pros of single views: less view files to maintain The obvious cons are the opposites of the pros: more files to maintain or more complicated view files. Which do you prefer? Why? Any pros/cons I haven't outlined here? Update: Assume each view uses a layout page and partial views to abstract the obviously repetitive code.

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  • What's the reason both Image and Bitmap classes don't implement a custom equality/hashcode logic?

    - by devoured elysium
    From MSDN documentation, it seems as both GetHashCode() and Equals() haven't been overriden in Bitmap. Neither have them been overriden in Image. So both classes are using the Object's version of them just compares references. I wasn't too convinced so I decided to fire up Reflector to check it out. It seems MSDN is correct in that matter. So, is there any special reason why MS guys wouldn't implement "comparison logic", at least for the Bitmap class? I find it is kinda acceptable for Image, as it is an abstract class, but not so much for the Bitmap class. I can see in a lot of situations calculating the hash code can be an expensive operation, but it'd be alright if it used some kind of lazy evaluation (storing the computed hash code integer in a variable a variable, so it wouldn't have to calculate it later again). When wanting to compare 2 bitmaps, will I have to resort to having to run all over the picture comparing each one of its pixels? Thanks

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  • Self-type mismatch in Scala

    - by Alexey Romanov
    Given this: abstract class ViewPresenterPair { type V <: View type P <: Presenter trait View {self: V => val presenter: P } trait Presenter {self: P => var view: V } } I am trying to define an implementation in this way: case class SensorViewPresenter[T] extends ViewPresenterPair { type V = SensorView[T] type P = SensorPresenter[T] trait SensorView[T] extends View { } class SensorViewImpl[T](val presenter: P) extends SensorView[T] { presenter.view = this } class SensorPresenter[T] extends Presenter { var view: V } } Which gives me the following errors: error: illegal inheritance; self-type SensorViewPresenter.this.SensorView[T] does not conform to SensorViewPresenter.this.View's selftype SensorViewPresenter.this.V trait SensorView[T] extends View { ^ <console>:13: error: type mismatch; found : SensorViewPresenter.this.SensorViewImpl[T] required: SensorViewPresenter.this.V presenter.view = this ^ <console>:16: error: illegal inheritance; self-type SensorViewPresenter.this.SensorPresenter[T] does not conform to SensorViewPresenter.this.Presenter's selftype SensorViewPresenter.this.P class SensorPresenter[T] extends Presenter { ^ I don't understand why. After all, V is just an alias for SensorView[T], and the paths are the same, so how can it not conform?

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  • extend web server to serve static files

    - by Turtle
    Hello, I want to extend a web server which is only able to handle RPC handling now. The web server is written in C#. It provides a abstract handler function like following: public string owsHandler(string request, string path, string param, OSHttpRequest httpRequest, OSHttpResponse httpResponse) And I wrote following code to handle image files: Bitmap queryImg = new Bitmap(path); System.IO.MemoryStream stream = new System.IO.MemoryStream(); queryImg.Save(stream, System.Drawing.Imaging.ImageFormat.Bmp); queryImg.Dispose(); byte[] byteImage = stream.ToArray(); stream.Dispose(); return Convert.ToBase64String(byteImage); And I test it in the browser, the image is returned but the image dimension info is missed. Shall I add something more to the code? Or is any general way to server static files? I do not want to serve it in a ASP.net server. Thanks

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  • how can I implement Comparable more than once?

    - by codeman73
    I'm upgrading some code to Java 5 and am clearly not understanding something with Generics. I have other classes which implement Comparable once, which I've been able to implement. But now I've got a class which, due to inheritance, ends up trying to implement Comparable for 2 types. Here's my situation: I've got the following classes/interfaces: interface Foo extends Comparable<Foo> interface Bar extends Comparable<Bar> abstract class BarDescription implements Bar class FooBar extends BarDescription implements Foo With this, I get the error 'interface Comparable cannot be implemented more than once with different arguments...' Why can't I have a compareTo(Foo foo) implemented in FooBar, and also a compareTo(Bar) implemented in BarDescription? Isn't this simply method overloading?

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  • EntityManager and two DAO with PersistenceContextType.EXTENDED

    - by hsd
    Hi All, I have a problem with my entity manager in my application. I have two DAO clasess like this: @Repository public abstract class DaoA { protected ClassA persistentClass; @PersistenceContext(name="my.persistence", type=PersistenceContextType.EXTENDED) protected EntityManager entityManager; -------------- some typical action for DAO -------------- } Second DAO is for ClassB and looks similar to DaoA. The rest of things are done for me by the Spring framework. When I'm debugging the application I recognize that both DAO objects have different instances of EntityManager. In the result my two different DAOs are connected with different PersistenceContext. Question is if this is correct behaviour or not? I would like to have the same PersistenceContext for all my DAO classes. Please give me a hint if this is possible and if I understood the JPA correctly? Regards Hsd

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  • Is testability alone justification for dependency injection?

    - by fearofawhackplanet
    The advantages of DI, as far as I am aware, are: Reduced Dependencies More Reusable Code More Testable Code More Readable Code Say I have a repository, OrderRepository, which acts as a repository for an Order object generated through a Linq to Sql dbml. I can't make my orders repository generic as it performs mapping between the Linq Order entity and my own Order POCO domain class. Since the OrderRepository by necessity is dependent on a specific Linq to Sql DataContext, parameter passing of the DataContext can't really be said to make the code reuseable or reduce dependencies in any meaningful way. It also makes the code harder to read, as to instantiate the repository I now need to write new OrdersRepository(new MyLinqDataContext()) which additionally is contrary to the main purpose of the repository, that being to abstract/hide the existence of the DataContext from consuming code. So in general I think this would be a pretty horrible design, but it would give the benefit of facilitating unit testing. Is this enough justification? Or is there a third way? I'd be very interested in hearing opinions.

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  • Why is the base() constructor not necessary?

    - by Earlz
    Hello, I have a class structure like abstract class Animal { public Animal(){ //init stuff.. } } class Cat : Animal { public Cat(bool is_keyboard) : base() //NOTE here { //other init stuff } } Now then, look at the noted line. If you remove : base() then it will compile without an error. Why is this? Is there a way to disable this behavior? I have had multiple bugs now from forgetting the base() which I would have thought to be required on such a special thing as a constructor.

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  • Code don't work, can't read property 'className' of undefined

    - by Arlen Beiler
    What is wrong with this code? var divarray = []; var articleHTML = []; var absHTML; var keyHTML; var bodyHTML = []; var i = 0; divarray = document.getElementById("yui-main").getElementsByTagName("div"); for ( var j in divarray) { if(divarray[i].className == "articleBody"){ alert("found"); articleHTML = divarray[i]; break; } bodyHTML[i] = ''; if(articleHTML[i].className == "issueMiniFeature"){continue;} if(articleHTML[i].className == "abstract"){absHTML = articleHTML[i]; continue;} if(articleHTML[i].className == "journalKeywords"){keyHTML = articleHTML[i]; continue;} bodyHTML[i] = articleHTML[i]; i++; } The error I get is: TypeError: Cannot read property 'className' of undefined I am using Google Chrome.

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  • Is there any graphics library in a higher level than OpenGL

    - by Turtle
    Hello, I am looking for a graphics library for 3D reconstruction research to develop my specific viewer based on some library. OpenGL seems in a low level and I have to remake the wheel everywhere. And I also tried VTK(visualization toolkit). However, it seems too abstract that I need to master many conceptions before I start. Is there any other graphics library? I prefer to program in python. So I would like the library has a python wrapper. I think something like O3D would be better. But O3D is for javascript and it seems that Google already stops the development.

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  • Capturing USB Plug/Unplug events in Firemonkey

    - by radsdau
    [RAD Studio XE3 / C++] I have a FMX project running in Windows only at this stage, but I need to detect events when USB devices are connected and disconnected. I have a similar VCL app that can do this fine, but the Application-HookMainWindow is not exposed in FMX (only VCL). Is there an elegant way to handle this? Or do I have to hack some VCL stuff into my FMX app to make that work? I'd imagine I have to abstract it so I can support other platforms down the track. For the meantime though I need to get the Windows solution working. If the 'VCL hack' thing is required, how would I reference the vcl::Forms::Application from within my Fmx app? Cheers.

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  • C# BinarySearch breaks when inheriting from something that implements IComparable<T>?

    - by Ender
    In .NET the BinarySearch algorithm (in Lists, Arrays, etc.) appears to fail if the items you are trying to search inherit from an IComparable instead of implementing it directly: List<B> foo = new List<B>(); // B inherits from A, which implements IComparable<A> foo.Add(new B()); foo.BinarySearch(new B()); // InvalidOperationException, "Failed to compare two elements in the array." Where: public abstract class A : IComparable<A> { public int x; public int CompareTo(A other) { return x.CompareTo(other.x); } } public class B : A {} Is there a way around this? Implementing CompareTo(B other) in class B doesn't seem to work.

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  • Auto-Complete Suggestions in Source Code Editor

    - by Jim
    Hello, Most IDEs (Eclipse, Netbeans, Intelij) provide contextually smart suggestions about the current statement you're writing. We would like to do the same thing (In Java for Java). We considered tokenizing the input and building our own abstract syntax trees, but quickly realized that could be a month long project in and of its self. We also started digging through the source code for the above mentioned IDEs, but it appears (correct me if I'm wrong) that the auto-complete code is pretty tightly woven with the rest of the IDE. We're wondering if anyone knows of a relatively isolated package that we could pull into our project to provide this auto-complete functionality. Thanks!

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  • Rails - building an absolute url in a model's virtual attribute without url helper

    - by Nick
    I have a model that has paperclip attachments. The model might be used in multiple rails apps I need to return a full (non-relative) url to the attachment as part of a JSON API being consumed elsewhere. I'd like to abstract the paperclip aspect and have a simple virtual attribute like this: def thumbnail_url self.photo.url(:thumb) end This however only gives me the relative path. Since it's in the model I can't use the URL helper methods, right? What would be a good approach to prepending the application root url since I don't have helper support? I would like to avoid hardcoding something or adding code to the controller method that assembles my JSON. Thank you

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