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  • How can I use a prefix for the fields in my strongly typed View?

    - by deadtime
    Hi, I have an EditProfile action in my PersonController, that finds a Person object by ID and does return View(person). The EditProfile view has a bunch of fields that should be filled in with the information from the Person object. One of the fields is named "Person.FirstName", and is not filled in automatically when the View is rendered. However, if I rename the textbox to "FirstName", it gets filled in. My question is: How can I specify to the view that it should use the "Person" prefix when filling in the information from the Person object? The reason I want to do this is because of consistency - in some of my views I allow the user to edit more than one object at the same time, and use prefixes in order to bind these correctly.

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  • How to reflect over T to build an expression tree for a query?

    - by Alex
    Hi all, I'm trying to build a generic class to work with entities from EF. This class talks to repositories, but it's this class that creates the expressions sent to the repositories. Anyway, I'm just trying to implement one virtual method that will act as a base for common querying. Specifically, it will accept a an int and it only needs to perform a query over the primary key of the entity in question. I've been screwing around with it and I've built a reflection which may or may not work. I say that because I get a NotSupportedException with a message of LINQ to Entities does not recognize the method 'System.Object GetValue(System.Object, System.Object[])' method, and this method cannot be translated into a store expression. So then I tried another approach and it produced the same exception but with the error of The LINQ expression node type 'ArrayIndex' is not supported in LINQ to Entities. I know it's because EF will not parse the expression the way L2S will. Anyway, I'm hopping someone with a bit more experience can point me into the right direction on this. I'm posting the entire class with both attempts I've made. public class Provider<T> where T : class { protected readonly Repository<T> Repository = null; private readonly string TEntityName = typeof(T).Name; [Inject] public Provider( Repository<T> Repository) { this.Repository = Repository; } public virtual void Add( T TEntity) { this.Repository.Insert(TEntity); } public virtual T Get( int PrimaryKey) { // The LINQ expression node type 'ArrayIndex' is not supported in // LINQ to Entities. return this.Repository.Select( t => (((int)(t as EntityObject).EntityKey.EntityKeyValues[0].Value) == PrimaryKey)).Single(); // LINQ to Entities does not recognize the method // 'System.Object GetValue(System.Object, System.Object[])' method, // and this method cannot be translated into a store expression. return this.Repository.Select( t => (((int)t.GetType().GetProperties().Single( p => (p.Name == (this.TEntityName + "Id"))).GetValue(t, null)) == PrimaryKey)).Single(); } public virtual IList<T> GetAll() { return this.Repository.Select().ToList(); } protected virtual void Save() { this.Repository.Update(); } }

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  • empty sharepoint user profile property throw an exception

    - by James123
    I have a user profile property. user not assigned any value that property. If I use below code. It is thorwing exception " object reference not set to an instance of an object " userprof["OptOut"].ToString() I tried all types like if (userprof["OptOut"] != null) OR if(userprof["OptOut"].Value != null) nothing worked out for me. Here userProf object has value. userprof["OptOut"].Value is null How to handle this?

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  • String Sharing/Reference issue with objects in Delphi

    - by jenakai123
    My application builds many objects in memory based on filenames (among other string based information). I was hoping to optimise memory usage by storing the path and filename separately, and then sharing the path between objects in the same path. I wasn't trying to look at using a string pool or anything, basically my objects are sorted so if I have 10 objects with the same path I want objects 2-10 to have their path "pointed" at object 1's path (eg object[2].Path=object[1].Path); I have a problem though, I don't believe that my objects are in fact sharing a reference to the same string after I think I am telling them to (by the object[2].Path=object[1].Path assignment). When I do an experiment with a string list and set all the values to point to the first value in the list I can see the "memory conservation" in action, but when I use objects I see absolutely no change at all, admittedly I am only using task manager (private working set) to watch for memory use changes. Here's a contrived example, I hope this makes sense. I have an object: TfileObject=class(Tobject) FpathPart: string; FfilePart: string; end; Now I create 1,000,000 instances of the object, using a new string for each one: var x: integer; MyFilePath: string; fo: TfileObject; begin for x := 1 to 1000000 do begin // create a new string for every iteration of the loop MyFilePath:=ExtractFilePath(Application.ExeName); fo:=TfileObject.Create; fo.FpathPart:=MyFilePath; FobjectList.Add(fo); end; end; Run this up and task manager says I am using 68MB of memory or something. (Note that if I allocated MyFilePath outside of the loop then I do save memory because of 1 instance of the string, but this is a contrived example and not actually how it would happen in the app). Now I want to "optimise" my memory usage by making all objects share the same instance of the path string, since it's the same value: var x: integer; begin for x:=1 to FobjectList.Count-1 do begin TfileObject(FobjectList[x]).FpathPart:=TfileObject(FobjectList[0]).FpathPart; end; end; Task Manager shows absouletly no change. However if I do something similar with a TstringList: var x: integer; begin for x := 1 to 1000000 do begin FstringList.Add(ExtractFilePath(Application.ExeName)); end; end; Task Manager says 60MB memory use. Now optimise with: var x: integer; begin for x := 1 to FstringList.Count - 1 do FstringList[x]:=FstringList[0]; end; Task Manager shows the drop in memory usage that I would expect, now 10MB. So I seem to be able to share strings in a string list, but not in objects. I am obviously missing something conceptually, in code or both! I hope this makes sense, I can really see the ability to conserve memory using this technique as I have a lot of objects all with lots of string information, that data is sorted in many different ways and I would like to be able to iterate over this data once it is loaded into memory and free some of that memory back up again by sharing strings in this way. Thanks in advance for any assistance you can offer.

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  • How do I change the auto complete behavior in the VS 2010 editor?

    - by pinkmuppet
    How do I stop VS 2010 (RC) from autocompleting html helpers with new object { ... } when I just want to pass in an anonymous type? Backspacing is driving me crazy. e.g., VS wants: <%=Html.ActionLink("Register", "Register", new object { controller = "Account" }) %> I know the helper is declared expecting object, which is why it does this, but can I change this behavior just for mvc helpers?

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  • LINQ to SQL - database relationships won't update after submit

    - by Quantic Programming
    I have a Database with the tables Users and Uploads. The important columns are: Users -> UserID Uploads -> UploadID, UserID The primary key in the relationship is Users -> UserID and the foreign key is Uploads -> UserID. In LINQ to SQL, I do the following operations: Retrieve files var upload = new Upload(); upload.UserID = user.UserID; upload.UploadID = XXX; db.Uploads.InsertOnSubmit(upload) db.SubmitChanges(); If I do that and rerun the application (and the db object is re-built, of course) - if do something like this: foreach(var upload in user.Uploads) I get all the uploads with that user's ID. (like added in the previous example) The problem is, that my application, after adding an upload an submitting changes, doesn't update the user.Uploads collection. i.e - I don't get the newly added uploads. The user object is stored in the Session object. At first, I though that the LINQ to SQL Framework doesn't update the reference of the object, therefore I should simply "reset" the user object from a new SQL request. I mean this: Session["user"] = db.Users.Where(u => u.UserID == user.UserID).SingleOrDefault(); (Where user is the previous user) But it didn't help. Please note: After rerunning the application, user.Uploads does have the new upload! Did anyone experience this type of problem, or is it normal behavior? I am a newbie to this framework. I would gladly take any advice. Thank you!

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  • Using intermediate array for hashCode and equals

    - by Basilevs
    As its a pain to handle structural changes of the class in two places I often do: class A { private B bChild; private C cChild; private Object[] structure() { return new Object[]{bChild, cChild}; } int hashCode() { Arrays.hashCode(structure); } boolean equals(Object that) { return Arrays.equals(this.structure(), ((A)that).structure()); } } What's bad about this approach besides boxing of primitives? Can it be improved?

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  • rvalues and temporary objects in the FCD

    - by FredOverflow
    It took me quite some time to understand the difference between an rvalue and a temporary object. But now the final committee draft states on page 75: An rvalue [...] is an xvalue, a temporary object or subobject thereof, or a value that is not associated with an object. I can't believe my eyes. This must be an error, right?

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  • How to draw mutiple rectangles using c#

    - by Nivas
    I have drawn and saved the Rectangle on the image i loaded in the picture box. How i like to draw multiple rectangles for that i tried array in the rectangle but it gives error ("Object reference not set to an instance of an object." (Null reference Exception was unhandled). enter code here private void pictureBox1_MouseDown(object sender, MouseEventArgs e) { if (mybitmap == null) { mybitmap = new Bitmap(sz.Width, sz.Height); } rect = new Rectangle(e.X, e.Y, 0, 0); this.Invalidate(); } private void pictureBox1_MouseMove(object sender, MouseEventArgs e) { if (stayToolStripMenuItem.Checked == true) { switch (e.Button) { case MouseButtons.Left: { rect = new Rectangle(rect.Left, rect.Top, e.X - rect.Left, e.Y - rect.Top); pictureBox1.Invalidate(); break; } } } } private void pictureBox1_Paint(object sender, PaintEventArgs e) { if (stayToolStripMenuItem.Checked == true) { button1.Visible = true; button2.Visible = true; if (mybitmap == null) { return; } using (g = Graphics.FromImage(mybitmap)) { using (Pen pen = new Pen(Color.Red, 2)) { //g.Clear(Color.Transparent); e.Graphics.DrawRectangle(pen, rect); label1.Top = rect.Top; label1.Left = rect.Left; label1.Width = rect.Width; label1.Height = rect.Height; if (label1.TextAlign == ContentAlignment.TopLeft) { e.Graphics.DrawString(label1.Text, label1.Font, new SolidBrush(label1.ForeColor), rect); g.DrawString(label1.Text, label1.Font, new SolidBrush(label1.ForeColor), rect); g.DrawRectangle(pen, rect); } } } } } How can i do this.....

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  • Is It Possible To Cast A Range

    - by Brad Rhoads
    I'd like to do something like this: def results = Item.findAll("from Item c, Tag b, ItemTag a where c = a.item and b = a.tag and (b.tag like :q or c.uri like :q) " + ob,[q:q]) def items = (Item) results[0..1][0] but I get Cannot cast object '[Ljava.lang.Object;@1e224a5' with class '[Ljava.lang.Object;' to class 'org.maflt.ibidem.Item' I can get what I need with this, but it doesn't seem like it's the best solution: def items = [] as Set def cnt = results.size() for (i=0;i<cnt-1;i++) { items << results[i][0] } items = items as List

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  • Why Is the sender type null when dealing with events

    - by ChloeRadshaw
    From C# Via CLR: Note A lot of people wonder why the event pattern requires the sender parameter to always be of type Object After all, since the MailManager will be the only type raising an event with a NewMail EventArgs object, it makes more sense for the callback method to be prototyped like this: void MethodName(Mai l Manager sender, NewMail EventArgs e); The pattern requires the sender parameter to be of type Object mostly because of inheritance What if Mai lManager were used as a base class for SmtpMailManager? In this case, the callback method should have the sender parameter prototyped as SmtpMailManager instead of Mail Manager, but this can’t happen because SmtpMai lManager just inherited the NewMai l event So the code that was expecting SmtpMail Manager to raise the event must still have to cast the sender argument to SmtpMailManager In other words, the cast is still required, so the sender parameter might as well be typed as Obj ect The next reason for typing the sender parameter as Obj ect is just fexibility It allows the delegate to be used by multiple types that offer an event that passes a NewMail EventArgs object For example, a PopMai lManager class could use the delegate even if this class were not derived from Mail Manager I just simply cannot understand why the sender is an object - Why can it not be generified? so most of the time we do not need to do generic casts

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  • GAE transaction exception suggestion

    - by bach
    Hi, The current situation encourages the design of the system to split object fields to seperate objects in order to reduce the chance of the JDOCanRetryException to be thrown. If we could have the fields that were changed by the other client who changed the object in the exception content itself we could deside whether to re-retrieve the object or ignore...

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  • StreamSocket to Stream in windows phone 8

    - by Abouzar Nouri
    I am trying to use Bluetooth in WP8 to send an image from my app on a device and show it in my app on another device. The receiver has a StreamSocket object to read the data from it like the code below await _dataReader.LoadAsync(4); uint messageLen = (uint)_dataReader.ReadInt32(); await _dataReader.LoadAsync(messageLen); string imageData _dataReader.ReadString(messageLen); Then I have to save all the received data (image) on the device and then create a Stream object from the stored data to give it to the BitmapSource.SetSource(Stream) function to be able to show this image on my app. var image = new BitmapImage(); image.SetSource(stream); All I want to do is not to skip this double work and directly convert the StreamSocket object (from Bluetooth connection) to a Stream object and make the BitmapSource image. Is there any way to do this?

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  • Get Youtube Video ID from html code with PHP

    - by asumaran
    I want to get all only youtube video ID from html code look the (or multiple) object/embed code for youtube video // html from database <p>loremm ipsum dolor sit amet enot <a href="link" attribute=""blah blah blah">anchor link</a> </p> <object width="425" height="344"> <param name="movie" value="http://www.youtube.com/v/Ou5eVl5eqtg&hl=es_ES&fs=1&"></param> <param name="allowFullScreen" value="true"></param> <param name="allowscriptaccess" value="always"></param> <embed src="http://www.youtube.com/v/Ou5eVl5eqtg&hl=es_ES&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"> </embed> </object> <image src="path/to/image.ext" > <p>lorem ipsum dolor sit amet... blah</p> <p>lorem ipsum dolor sit amet... blah</p> <object width="425" height="344"> <param name="movie" value="http://www.youtube.com/v/Ou5eVl5eqtg&hl=es_ES&fs=1&"></param> <param name="allowFullScreen" value="true"></param> <param name="allowscriptaccess" value="always"></param> <embed src="http://www.youtube.com/v/Ou5eVl5eqtg&hl=es_ES&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"> </embed> </object> <p>blah</p> blah<br/> blah<br/> blah<br/>

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  • How can I center a box of unknown width in CSS?

    - by NXTBoy
    I have this html: <div class="object-box"> <img ... /> <span class="caption">This is the caption</span> </div> Which is accompanied with this CSS: .object-box .caption, .object-box img { display: block; } .object-box { border: 1px solid; } I would like the surrounding div to shrink-wrap to its contents. I can achieve this by using float: ... or display: inline-block. However, I'd also like it to be centered on the page, using margin: auto. The two approaches don't seem to be compatible. Is it possible to create such a shrink-wrapped, centered container, without adding a wrapper element?

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  • When to retain a "delegate"

    - by Jose
    I know that in Objective-C you should never retain your delegates because it may cause a retain-cycle, however, how do you know the difference between a delegate and a non-delegate object ? Can't it be said that just sending a message to any object is delegating work to that object ?

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  • Force deletion of slot in boost::signals2

    - by villintehaspam
    Hi! I have found that boost::signals2 uses sort of a lazy deletion of connected slots, which makes it difficult to use connections as something that manages lifetimes of objects. I am looking for a way to force slots to be deleted directly when disconnected. Any ideas on how to work around the problem by designing my code differently are also appreciated! This is my scenario: I have a Command class responsible for doing something that takes time asynchronously, looking something like this (simplified): class ActualWorker { public: boost::signals2<void ()> OnWorkComplete; }; class Command : boost::enable_shared_from_this<Command> { public: ... void Execute() { m_WorkerConnection = m_MyWorker.OnWorkDone.connect(boost::bind(&Command::Handle_OnWorkComplete, shared_from_this()); // launch asynchronous work here and return } boost::signals2<void ()> OnComplete; private: void Handle_OnWorkComplete() { // get a shared_ptr to ourselves to make sure that we live through // this function but don't keep ourselves alive if an exception occurs. shared_ptr<Command> me = shared_from_this(); // Disconnect from the signal, ideally deleting the slot object m_WorkerConnection.disconnect(); OnComplete(); // the shared_ptr now goes out of scope, ideally deleting this } ActualWorker m_MyWorker; boost::signals2::connection m_WorkerConnection; }; The class is invoked about like this: ... boost::shared_ptr<Command> cmd(new Command); cmd->OnComplete.connect( foo ); cmd->Execute(); // now go do something else, forget all about the cmd variable etcetera. the Command class keeps itself alive by getting a shared_ptr to itself which is bound to the ActualWorker signal using boost::bind. When the worker completes, the handler in Command is invoked. Now, since I would like the Command object to be destroyed, I disconnect from the signal as can be seen in the code above. The problem is that the actual slot object is not deleted when disconnected, it is only marked as invalid and then deleted at a later time. This in turn appears to depend on the signal to fire again, which it doesn't do in my case, leading to the slot never expiring. The boost::bind object thus never goes out of scope, holding a shared_ptr to my object that will never get deleted. I can work around this by binding using the this pointer instead of a shared_ptr and then keeping my object alive using a member shared_ptr which I then release in the handler function, but it kind of makes the design feel a bit overcomplicated. Is there a way to force signals2 to delete the slot when disconnecting? Or is there something else I could do to simplify the design? Any comments are appreciated!

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  • How solve consumer/producer task using semaphores

    - by user1074896
    I have SimpleProducerConsumer class that illustrate consumer/producer problem (I am not sure that it's correct). public class SimpleProducerConsumer { private Stack<Object> stack = new Stack<Object>(); private static final int STACK_MAX_SIZE = 10; public static void main(String[] args) { SimpleProducerConsumer pc = new SimpleProducerConsumer(); new Thread(pc.new Producer(), "p1").start(); new Thread(pc.new Producer(), "p2").start(); new Thread(pc.new Consumer(), "c1").start(); new Thread(pc.new Consumer(), "c2").start(); new Thread(pc.new Consumer(), "c3").start(); } public synchronized void push(Object d) { while (stack.size() >= STACK_MAX_SIZE) try { wait(); } catch (InterruptedException e) { e.printStackTrace(); } try { Thread.sleep(1000); } catch (InterruptedException e) { e.printStackTrace(); } stack.push(new Object()); System.out.println("push " + Thread.currentThread().getName() + " " + stack.size()); notify(); } public synchronized Object pop() { while (stack.size() == 0) try { wait(); } catch (InterruptedException e) { e.printStackTrace(); } try { Thread.sleep(50); } catch (InterruptedException e) { e.printStackTrace(); } stack.pop(); System.out.println("pop " + Thread.currentThread().getName() + " " + stack.size()); notify(); return null; } class Consumer implements Runnable { @Override public void run() { while (true) { pop(); } } } class Producer implements Runnable { @Override public void run() { while (true) { push(new Object()); } } } } I found simple realization of semaphore(here:http://docs.oracle.com/javase/tutorial/essential/concurrency/guardmeth.html I know that there is concurrency package) How I need to change code to exchange java objects monitors to my custom semaphore. (To illustrate C/P problem using semaphores) Semaphore: class Semaphore { private int counter; public Semaphore() { this(0); } public Semaphore(int i) { if (i < 0) throw new IllegalArgumentException(i + " < 0"); counter = i; } public synchronized void release() { if (counter == 0) { notify(); } counter++; } public synchronized void acquire() throws InterruptedException { while (counter == 0) { wait(); } counter--; } }

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  • C# Casting system.__comobject to class type

    - by ijrufus
    I have an Excel Add-In that I'm currently trying to set up a unit test framework for. For the unit tests I've followed this guide: http://blogs.msdn.com/b/varsha/archive/2010/08/17/writing-automated-test-cases-for-vsto-application.aspx It seems to work fine, until I want to return a class object from my interface. Specifying the class object as the return type throws a "return argument has an invalid type" exception when calling the method. Changing the return type from the class to an object allows me to call the method and get the object, but now I'm unable to cast it as the class and use it as intended, getting this exception message when I try: > Unable to cast COM object of type 'System.__ComObject' to class type > 'anaplan.Utility.XYCoordinates'. Instances of types that represent COM > components cannot be cast to types that do not represent COM > components; however they can be cast to interfaces as long as the > underlying COM component supports QueryInterface calls for the IID of > the interface. I've retrieved the Type name using VisualBasic.Information.TypeName and it's showing it as the class I expect. Is there any way to get the comobject cast back to the class? Or another way to access the properties it has? Or am I just being a bit stupid here?

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  • Is it any loose coupling mechanism in Objective-C + Cocoa like C# delegates or C++Qt signals+slots?

    - by Eye of Hell
    Hello. For a large programs, the standard way to chalenge a complexity is to divide a program code into small objects. Most of the actual programming languages offer this functionality via classes, so is Objective-C. But after source code is separated into small object, the second challenge is to somehow connect them with each over. Standard approaches, supported by most languages are compositon (one object is a member field of another), inheritance, templates (generics) and callbacks. More cryptic techniques include method-level delagates (C#) and signals+slots (C++Qt). I like the delegates / signals idea, since while connecting two objects i can connect individual methods with each over, without objects knowing anything of each over. For C#, it will look like this: var object1 = new CObject1(); var object2 = new CObject2(); object1.SomethingHappened += object2.HandleSomething; In this code, is object1 calls it's SomethingHappened delegate (like a normal method call) the HandleSomething method of object2 will be called. For C++Qt, it will look like this: var object1 = new CObject1(); var object2 = new CObject2(); connect( object1, SIGNAL(SomethingHappened()), object2, SLOT(HandleSomething()) ); The result will be exactly the same. This technique has some advantages and disadvantages, but generally i like it more than interfaces since if program code base grows i can change connections and add new ones without creating tons of interfaces. After examination of Objective-C i havn't found any way to use this technique i like :(. It seems that Objective-C supports message passing perfectly well, but it requres for object1 to have a pointer to object2 in order to pass it a message. If some object needs to be connected to lots of other objects, in Objective-C i will be forced to give him pointers to each of the objects it must be connected. So, the question :). Is it any approach in Objective-C programming that will closely resemble delegate / signal+slot types of connection, not a 'give first object an entire pointer to second object so it can pass a message to it'. Method-level connections are a bit more preferable to me than object-level connection ^_^.

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  • How to stop attributes from being pickled in Python

    - by Ries
    I am using gnosis.xml.pickle to convert an object of my own class to xml. The object is initialized so that: self.logger = MyLogger() But when I do dump the object to a string I get an exception stating that the pickler encountered an unpickleable type . Is there a way to 'tag' the logger attribute so that pickler will know not to try and pickle that attribute?

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  • Long time to load first sql connection in .NET

    - by Shrage Smilowitz
    For some reason it takes 7 seconds to open a connection to a sql server database for the firt time, subsequent connections takes a second. any idea what could be the reason? I'm using C# and asp.net Its after compilation, i essence every time i restart the site, which means every time it needs to actualy create the "first" connection. i understand that setting up connection pooling has overhead, but i have never seen that i should take 7 second to set it up.

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  • C# == operator in Immediate window behaves differently than at run-time

    - by Damiano
    Try the following in the Immediate window: object a1 = "a"; object a2 = "a"; a1==a2 // outputs false and you'll see that a1 == a2 outputs false. However, at runtime in either a window app or console, you'll get true: object t1 = "a"; object t2 = "a"; MessageBox.Show((t1 == t2).ToString()); // outputs true The runtime behavior is consistent with the definition for the == operator and strings. Does anybody know if this a bug in the Immediate window?

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