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  • Problems with type and ext attribute of artifact

    - by user315228
    Hi, I have following definition in ivy.xml <dependency org="southbeach" name="ego" rev="4.3.1" conf="properties->asterik" > <artifact name="ego" type="conf" ext="conf" conf="properties->asterik"/> </dependency> I have files with either extension conf or properties which i need at runtime, in ivysettings.xml, i have following: <filesystem name="privateFSa"> <artifact pattern="${localRepositoryLocation}/[artifact].[ext]" /> </filesystem> It always tries to look for ego.jar instead of ego.conf. can please somebody shed light on this? am i doing something wrong or ivy just supports tar,zip,gz, jar and not properties or conf files? I did workaround for now in ivysettings.xml <filesystem name="privateFSa"> <artifact pattern="${localRepositoryLocation}/[artifact].conf" /> </filesystem> but this doesnt looks good to hardcode conf there. Thanks, Almas

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  • Python namespace in between builtins and global?

    - by Paul
    Hello, As I understand it python has the following outermost namespaces: Builtin - This namespace is global across the entire interpreter and all scripts running within an interpreter instance. Globals - This namespace is global across a module, ie across a single file. I am looking for a namespace in between these two, where I can share a few variables declared within the main script to modules called by it. For example, script.py: import Log from Log import foo from foo log = Log() foo() foo.py: def foo(): log.Log('test') # I want this to refer to the callers log object I want to be able to call script.py multiple times and in each case, expose the module level log object to the foo method. Any ideas if this is possible? It won't be too painful to pass down the log object, but I am working with a large chunk of code that has been ported from Javascript. I also understand that this places constraints on the caller of foo to expose its log object. Thanks, Paul

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  • Iteration order of HashSet

    - by eljenso
    If every object added to a java.util.HashSet implements Object.equals() and Object.hashCode() in a deterministic fashion, is the iteration order over the HashSet guaranteed to be identical for every identical set of elements added, irrespective of the order in which they were added?

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  • Android: Send arbitrary objects within Activities?

    - by Sebastian
    I have read some question here but I didn't find a solution. I have read about Parcelable, Intents, and sharing specific data within Activities from the android dev docs (both dev guide and reference). Here's the scenario: I have one ListActivity that fills in an object parsing an xml file, it shows a list of values, and when clicked I want to return the object that represents the item clicked to the activity that has called it, for then, call another activity with this object. I read on how to implement Parcelable but seems not being the way. Implementing Parcelable receives a Parcel for the constructor and then reads the values from it (or at least that was what I understood). This makes no sense for me and I can't see how to implement basing on that issue. I build the object parsing the xml file, not having a Parcel. I appreciate some clarifications on this, regards.

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  • Using a NullTempDataProvider crashes at PossiblyLoadTempData()

    - by Jova
    I'm trying to use a dummy TempDataProvider for some of my controllers. The provider looks like this. public class NullTempDataProvider : ITempDataProvider { public IDictionary<string, object> LoadTempData(ControllerContext controllerContext) { return new TempDataDictionary(); } public void SaveTempData(ControllerContext controllerContext, IDictionary<string, object> values) { } } But I'm getting an error that says System.NullReferenceException: Object reference not set to an instance of an object. at System.Web.Mvc.Controller.PossiblyLoadTempData() Any help for figuring out the reason for it is much appreciated.

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  • Singleton constructor question

    - by gillyb
    Hi, I created a Singleton class in c#, with a public property that I want to initialize when the Singleton is first called. This is the code I wrote : public class BL { private ISessionFactory _sessionFactory; public ISessionFactory SessionFactory { get { return _sessionFactory; } set { _sessionFactory = value; } } private BL() { SessionFactory = Dal.SessionFactory.CreateSessionFactory(); } private object thisLock = new object(); private BL _instance = null; public BL Instance { get { lock (thisLock) { if (_instance == null) { _instance = new BL(); } return _instance; } } } } As far as I know, when I address the Instance BL object in the BL class for the first time, it should load the constructor and that should initialize the SessionFactory object. But when I try : BL.Instance.SessionFactory.OpenSession(); I get a Null Reference Exception, and I see that SessionFactory is null... why?

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  • asp.net session error

    - by umeshchaurasia
    HI all, I am working with asp.net with c#.net Here i am using session state to pass the value from one page to another. i have two pages, in first page i am calculating the value and passing the value to second page using session and in second page i am displaying the message through the value. I am using these two pages for facebook application. I uploaded my two pages then i am checking with facebook by opening through internet explorer and its giving below error. Object reference not set to an instance of an object. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.NullReferenceException: Object reference not set to an instance of an object. But when i open my application using firefox the pages are working fine. please help me...

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  • DRYing out implementation of ICloneable in several classes

    - by Sarah Vessels
    I have several different classes that I want to be cloneable: GenericRow, GenericRows, ParticularRow, and ParticularRows. There is the following class hierarchy: GenericRow is the parent of ParticularRow, and GenericRows is the parent of ParticularRows. Each class implements ICloneable because I want to be able to create deep copies of instances of each. I find myself writing the exact same code for Clone() in each class: object ICloneable.Clone() { object clone; using (var stream = new MemoryStream()) { var formatter = new BinaryFormatter(); // Serialize this object formatter.Serialize(stream, this); stream.Position = 0; // Deserialize to another object clone = formatter.Deserialize(stream); } return clone; } I then provide a convenience wrapper method, for example in GenericRows: public GenericRows Clone() { return (GenericRows)((ICloneable)this).Clone(); } I am fine with the convenience wrapper methods looking about the same in each class because it's very little code and it does differ from class to class by return type, cast, etc. However, ICloneable.Clone() is identical in all four classes. Can I abstract this somehow so it is only defined in one place? My concern was that if I made some utility class/object extension method, it would not correctly make a deep copy of the particular instance I want copied. Is this a good idea anyway?

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  • How can I ignore an http request without clearing the browser?

    - by Timid Developer
    To prevent duplicate requests (i.e. pressing F5 right after clicking a command button), I've setup my page base class to ignore the request if it's detected as a duplicate. When I say 'ignore' I mean Response.End() Now I thought I've seen this work before, where there's an issue, I just Response.End() and the users page just does nothing. I don't know the exact circumstance in which this worked, but I'm unable to repeat it now. Now when I call Response.End(), I just get an empty browser. More specifically, I get this html. <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META http-equiv=Content-Type content="text/html; charset=utf-8"></HEAD> <BODY></BODY></HTML> I setup the following test app to confirm the problem is not elsewhere in my app. Here it is: Add the following to an aspx form <asp:Label ID="lbl" Text="0" runat="server" /><br /> <asp:Button ID="btnAdd1" Text="Add 1" runat="server" /><br /> <asp:Button ID="btnAdd2" Text="Add 2" runat="server" /><br /> <asp:Button ID="btnAdd3" Text="Add 3" runat="server" /><br /> And here's the code behind file using System; namespace TestDupRequestCancellation { public partial class _Default : System.Web.UI.Page { protected void Page_Init(object sender, EventArgs e) { btnAdd1.Click += btnAdd1_Click; btnAdd2.Click += btnAdd2_Click; btnAdd3.Click += btnAdd3_Click; } protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) CurrentValue = 0; else if (Int32.Parse(lbl.Text) != CurrentValue) Response.End(); } protected void Page_PreRender(object sender, EventArgs e) { lbl.Text = CurrentValue.ToString(); } protected int CurrentValue { get { return Int32.Parse(Session["CurrentValue"].ToString()); } set { Session["CurrentValue"] = value.ToString(); } } void btnAdd3_Click(object sender, EventArgs e) { CurrentValue += 3; } void btnAdd2_Click(object sender, EventArgs e) { CurrentValue += 2; } void btnAdd1_Click(object sender, EventArgs e) { CurrentValue += 1; } } } When you load the page, clicking any button does what is expected, but if you press F5 at any time after pressing one of the buttons, it will detect it as a duplicate request and call Response.End() which promptly ends the task. Which leaves the user with an empty browser. Is there anyway to leave the user with the page as it was, so they can just click a button? Also; please note that this code is the simplest code I could come up with to demonstrate my problem. It's not meant to demonstrate how to check for dup requests.

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  • Hibernate: Walk millions of rows and don't leak memory

    - by Autocracy
    The below code functions, but Hibernate never lets go of its grip of any object. Calling session.clear() causes exceptions regarding fetching a joined class, and calling session.evict(currentObject) before retrieving the next object also fails to free the memory. Eventually I exhaust my heap space. Checking my heap dumps, StatefulPersistenceContext is the garbage collector's root for all references pointing to my objects. public class CriteriaReportSource implements JRDataSource { private ScrollableResults sr; private Object currentObject; private Criteria c; private static final int scrollSize = 10; private int offset = 1; public CriteriaReportSource(Criteria c) { this.c = c; advanceScroll(); } private void advanceScroll() { // ((Session) Main.em.getDelegate()).clear(); this.sr = c.setFirstResult(offset) .setMaxResults(scrollSize) .scroll(ScrollMode.FORWARD_ONLY); offset += scrollSize; } public boolean next() { if (sr.next()) { currentObject = sr.get(0); if (sr.isLast()) { advanceScroll(); } return true; } return false; } public Object getFieldValue(JRField jrf) throws JRException { Object retVal = null; if(currentObject == null) { return null; } try { retVal = PropertyUtils.getProperty(currentObject, jrf.getName()); } catch (Exception ex) { Logger.getLogger(CriteriaReportSource.class.getName()).log(Level.SEVERE, null, ex); } return retVal; } }

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  • LINQ - Select Statement - The null value cannot be assigned to a member with type System.Int32 which

    - by thiag0
    I am trying to achieve the following... _4S.NJB_Request request = (from r in db.NJB_Requests where r.RequestId == referenceId select r).Take(1).SingleOrDefault(); Getting the following exception... Message: The null value cannot be assigned to a member with type System.Int32 which is a non-nullable value type. StackTrace: at System.Data.Linq.SqlClient.SqlProvider.Execute(Expression query, QueryInfo queryInfo, IObjectReaderFactory factory, Object[] parentArgs, Object[] userArgs, ICompiledSubQuery[] subQueries, Object lastResult) at System.Data.Linq.SqlClient.SqlProvider.ExecuteAll(Expression query, QueryInfo[] queryInfos, IObjectReaderFactory factory, Object[] userArguments, ICompiledSubQuery[] subQueries) at System.Data.Linq.SqlClient.SqlProvider.System.Data.Linq.Provider.IProvider.Execute(Expression query) at System.Data.Linq.DataQuery`1.System.Linq.IQueryProvider.Execute[S](Expression expression) at System.Linq.Queryable.SingleOrDefault[TSource](IQueryable`1 source) at DAL.SqlDataProvider.MarkNJBPCRequestAsComplete(Int32 referenceId, Int32 processState) I have verified that 'referenceId' does have a value. Anyone know why this would happen in a select statement? Thanks!

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  • Problem while adding a new value to a hashtable when it is enumerated

    - by karthik
    `hi I am doing a simple synchronous socket programming,in which i employed twothreads one for accepting the client and put the socket object into a collection,other thread will loop through the collection and send message to each client through the socket object. the problem is 1.i connect to clients to the server and start send messages 2.now i want to connect a new client,while doing this i cant update the collection and add a new client to my hashtable.it raises an exception "collection modified .Enumeration operation may not execute" how to add a NEW value without having problems in a hashtable. private void Listen() { try { //lblStatus.Text = "Server Started Listening"; while (true) { Socket ReceiveSock = ServerSock.Accept(); //keys.Clear(); ConnectedClients = new ListViewItem(); ConnectedClients.Text = ReceiveSock.RemoteEndPoint.ToString(); ConnectedClients.SubItems.Add("Connected"); ConnectedList.Items.Add(ConnectedClients); ClientTable.Add(ReceiveSock.RemoteEndPoint.ToString(), ReceiveSock); //foreach (System.Collections.DictionaryEntry de in ClientTable) //{ // keys.Add(de.Key.ToString()); //} //ClientTab.Add( //keys.Add( } //lblStatus.Text = "Client Connected Successfully."; } catch (Exception ex) { MessageBox.Show(ex.Message); } } private void btn_receive_Click(object sender, EventArgs e) { Thread receiveThread = new Thread(new ThreadStart(Receive)); receiveThread.IsBackground = true; receiveThread.Start(); } private void Receive() { while (true) { //lblMsg.Text = ""; byte[] Byt = new byte[2048]; //ReceiveSock.Receive(Byt); lblMsg.Text = Encoding.ASCII.GetString(Byt); } } private void btn_Send_Click(object sender, EventArgs e) { Thread SendThread = new Thread(new ThreadStart(SendMsg)); SendThread.IsBackground = true; SendThread.Start(); } private void btnlist_Click(object sender, EventArgs e) { //Thread ListThread = new Thread(new ThreadStart(Configure)); //ListThread.IsBackground = true; //ListThread.Start(); } private void SendMsg() { while (true) { try { foreach (object SockObj in ClientTable.Keys) { byte[] Tosend = new byte[2048]; Socket s = (Socket)ClientTable[SockObj]; Tosend = Encoding.ASCII.GetBytes("FirstValue&" + GenerateRandom.Next(6, 10).ToString()); s.Send(Tosend); //ReceiveSock.Send(Tosend); Thread.Sleep(300); } } catch (Exception ex) { MessageBox.Show(ex.Message); } } }

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  • Load an Assembly from Bin in ASP.NET

    - by Pete Michaud
    I have a file name, like "Foo.dll," for a library that I know is in the bin directory. I want to create an Assembly object for it. I'm trying to instantiate this object from a class that's not a page, so I don't have the Request object to get the path. How do I get the path I need to use Assembly.Load()?

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  • PHP: SimpleXML and Arrays

    - by acemasta
    When I run this code: foreach($xml->movie as $movie) { if(isset($movie->photos)) { foreach ($movie->photos as $photo) { echo $photo."&nbsp;"; } echo "<hr/>"; } } I get nice output of the actual data, e.g. a row looks like 06397001.jpg 06397002.jpg 06397003.jpg 06397004.jpg 06397005.jpg But when I throw it in an array, it includes all the SimpleXML wrapper tags and the jpgs are not at the root of the array. code: foreach($xml->movie as $movie) { if(isset($movie->photos)) { $photos = array(); foreach ($movie->photos as $photo) { $photos[] = $photo; } } else $photos = ""; var_dump($photos); echo "<hr />"; } e.g. same row looks like array(5) { [0]= object(SimpleXMLElement)#11 (1) { [0]= string(12) "06397001.jpg" } [1]= object(SimpleXMLElement)#12 (1) { [0]= string(12) "06397002.jpg" } [2]= object(SimpleXMLElement)#13 (1) { [0]= string(12) "06397003.jpg" } [3]= object(SimpleXMLElement)#14 (1) { [0]= string(12) "06397004.jpg" } [4]= object(SimpleXMLElement)#15 (1) { [0]= string(12) "06397005.jpg" } } Why is this happening/how can I remove this so I just get an array of the photos at root level like when I echo it? Thanks, sorry for the single line code formatting; was messing up when I tried to paste directly with line breaks.

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  • Can't instantiate javax.servlet.ServletException

    - by Denis
    Hello, experts! I am trying to create instance of class javax.servlet.ServletException with following code public class MyTroubleViewer { public static void main(String[] args) { javax.servlet.ServletException servletException = new javax.servlet.ServletException("Hello"); System.out.println(servletException.getMessage()); } } But I get exception on creating: Exception in thread "main" java.lang.ClassFormatError: Absent Code attribute in method that is not native or abstract in class file javax/servlet/ServletException ... Maven helps me with dependecies: <dependency> <groupId>javax</groupId> <artifactId>javaee-api</artifactId> <version>6.0</version> <type>jar</type> <scope>compile</scope> </dependency> What am I doing wrong?

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  • Is there a Firebug console -vsdoc.js?

    - by David Murdoch
    If not, does anyone care to write one? I would do it myself...but I don't have time right now...maybe next week (unless someone beats me to it). If you are bored and want to compile the vsdoc: Here is the Firebug API. Here is a blog post about the format for VS doc comments for intellisense. Here is an example vsdoc (jquery-1.4.1-vsdoc.js). I created the following because I kept typing cosnole instead of console. You can use it as a starting point (ish). console = { /// <summary> /// 1: The javascript console /// </summary> /// <returns type="Object" /> }; console.log = function (object) { /// <summary> /// Write to the console's log /// </summary> /// <returns type="null" /> /// <param name="object" type="Object"> /// Write the object to the console's log /// </param> };

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  • nHibernate query by example with multiple associated objects

    - by BurnWithLife
    I'm trying to use nhibernate's query by example to build dynamic queries. I'm stuck on how to code for an example object with multiple associations. Here's an example from NHibernate in Action. Its a User object with Items. Example exampleUser = Example.Create(u).IgnoreCase().EnableLike(MatchMode.Anywhere); Example exampleItem = Example.Create(i).IgnoreCase().EnableLike(MatchMode.Anywhere); return GetSession().CreateCriteria(typeof(User)) .Add( exampleUser ) .CreateCriteria("Items") .Add( exampleItem ) .List<User>(); If the User object has let's say a Category object as a property, how could I add that in to the above example? If i put another CreateCriteria at the end it refers to the Items, not the User.

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  • Request-local storage in ASP.NET (accessible to the code from IHttpModule implementation)

    - by IgorK
    I need to have some object hanging around between two events I'm interested in: PreRequestHandlerExecute (where I create an instance of my object and want to save it) and PostRequestHandlerExecute (where I want to get to the object). After the second event the object is not needed for my purposes and should be discarded either by storage or my explicit action. So the ideal context where my object should be stored is per request (with guaranteed no sharing issues when different threads are serving requests... or processes/servers :) ) Take into account that actual implementation I can do is being made from a HttpModule and is supposed to be a pluggable solution for already written web apps (so the option to provide some state using static/instance variables in Global.asax doesn't look good - I will have to modify Global.asax on every web application). Cache seems to be too broad for this use. I tried to see whether httpContext.Application (of type HttpApplicationState) is good for me or not, but cannot get whether it is exactly per HttpApplication instance or not (AFAIK you can have several instances of HttpApplications used on different threads and therefore serving several requests simultaneously - then using storage shared between threads will not work correctly; otherwise I would use it because one HttpApplication instance serves exactly one request at a time). Something could be done with storing state on the HttpModule instances if I know for sure that it's exactly bound 1-to-1 with every HttpApplication instance running (but again I need a proof that HttpApplication instance is 1-to-1 with my HttpModule's instance). Any valuable and reputable links on these topics are much appreciated... Would be great to find something particularly well-suited for per request situation (because otherwise I may end up with something ulgy... probably either some 'broader' scoped storage and some hacks to have different keys in the storage for different requests, OR using a thread-local thing and in this way commit to the theory that IIS/ASP.NET will not ever serve first event from one thread and the second event from the other thread and so on)

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  • Internet Explorer Automation: how to suppress Open/Save dialog?

    - by Vladimir Dyuzhev
    When controlling IE instance via MSHTML, how to suppress Open/Save dialogs for non-HTML content? I need to get data from another system and import it into our one. Due to budget constraints no development (e.g. WS) can be done on the other side for some time, so my only option for now is to do web scrapping. The remote site is ASP.NET-based, so simple HTML requests won't work -- too much JS. I wrote a simple C# application that uses MSHTML and SHDocView to control an IE instance. So far so good: I can perform login, navigate to desired page, populate required fields and do submit. Then I face a couple of problems: First is that report is opening in another window. I suspect I can attach to that window too by enumerating IE windows in the system. Second, more troublesome, is that report itself is CSV file, and triggers Open/Save dialog. I'd like to avoid it and make IE save the file into given location OR I'm fine with programmatically clicking dialog buttons too (how?) I'm actually totally non-Windows guy (unix/J2EE), and hope someone with better knowledge would give me a hint how to do those tasks. Thanks! UPDATE I've found a promising document on MSDN: http://msdn.microsoft.com/en-ca/library/aa770041.aspx Control the kinds of content that are downloaded and what the WebBrowser Control does with them once they are downloaded. For example, you can prevent videos from playing, script from running, or new windows from opening when users click on links, or prevent Microsoft ActiveX controls from downloading or executing. Slowly reading through... UPDATE 2: MADE IT WORK, SORT OF... Finally I made it work, but in an ugly way. Essentially, I register a handler "before navigate", then, in the handler, if the URL is matching my target file, I cancel the navigation, but remember the URL, and use WebClient class to access and download that temporal URL directly. I cannot copy the whole code here, it contains a lot of garbage, but here are the essential parts: Installing handler: _IE2.FileDownload += new DWebBrowserEvents2_FileDownloadEventHandler(IE2_FileDownload); _IE.BeforeNavigate2 += new DWebBrowserEvents2_BeforeNavigate2EventHandler(IE_OnBeforeNavigate2); Recording URL and then cancelling download (thus preventing Save dialog to appear): public string downloadUrl; void IE_OnBeforeNavigate2(Object ob1, ref Object URL, ref Object Flags, ref Object Name, ref Object da, ref Object Head, ref bool Cancel) { Console.WriteLine("Before Navigate2 "+URL); if (URL.ToString().EndsWith(".csv")) { Console.WriteLine("CSV file"); downloadUrl = URL.ToString(); } Cancel = false; } void IE2_FileDownload(bool activeDocument, ref bool cancel) { Console.WriteLine("FileDownload, downloading "+downloadUrl+" instead"); cancel = true; } void IE_OnNewWindow2(ref Object o, ref bool cancel) { Console.WriteLine("OnNewWindow2"); _IE2 = new SHDocVw.InternetExplorer(); _IE2.BeforeNavigate2 += new DWebBrowserEvents2_BeforeNavigate2EventHandler(IE_OnBeforeNavigate2); _IE2.Visible = true; o = _IE2; _IE2.FileDownload += new DWebBrowserEvents2_FileDownloadEventHandler(IE2_FileDownload); _IE2.Silent = true; cancel = false; return; } And in the calling code using the found URL for direct download: ... driver.ClickButton(".*_btnRunReport"); driver.WaitForComplete(); Thread.Sleep(10000); WebClient Client = new WebClient(); Client.DownloadFile(driver.downloadUrl, "C:\\affinity.dump"); (driver is a simple wrapper over IE instance = _IE) Hope that helps someone.

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  • What is the meaning of ": base" in the costructor definition ?

    - by DotNetBeginner
    What is the meaning of ": base" in the costructor of following class(MyClass) ? Please explain the concept behind constructor definition given below for class MyClass. public class MyClass: WorkerThread { public MyClass(object data): base(data) { // some code } } public abstract class WorkerThread { private object ThreadData; private Thread thisThread; public WorkerThread(object data) { this.ThreadData = data; } public WorkerThread() { ThreadData = null; } }

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  • Copy constructor with more than one parameter

    - by Ravi Gupta
    I am learning C++ and was reading copy constructor from the C++: The Complete Reference. The books says that It is permissible for a copy constructor to have additional parameters as long as they have default arguments defined for them. However, in all cases the first parameter must be a reference to the object doing the initializing. But I am confused that how we are going to pass those additional parameters? I am sure there should be some way which is not given in the book and which I am unable to figure out. Can anyone help me out? EDIT: Also is it possible to pass these extra parameters in all three cases i.e. ¦ When one object explicitly initializes another, such as in a declaration ¦ When a copy of an object is made to be passed to a function ¦ When a temporary object is generated (most commonly, as a return value)

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  • Design Patterns: What is a type

    - by contactmatt
    A very basic question, but after reading the "Design Patterns: Elements of reusable OO Software" book, I'm a little confused. The book states, "An object's type only refers to its interface-the set of request to which it can respond. An object can have many types, and objects of different classes can have the same type." Could someone please better explain what a Type is? I also don't understand how one object can have multiple types...unless the book is speaking of polymorphism....

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  • wpf observableCollection

    - by Asha
    I have an ObservableCollection which is dataContext for my treeview when I try to remove an Item from ObservableCollection I will get an error that Object reference not set to an instance of an object . can you please tell me why this error is happening and what is the solution thanks EDIT 1: The code is something like : class MyClass : INotifyPropertyChanged { //my class code here } public partial class UC_myUserControl : UserControl { private ObservableCollection<MyClass> myCollection = new ObservableCollection<MyClass>(); private void UserControl_Loaded(object sender, RoutedEventArgs e) { myCollection.add(new myClass); myTreeView.DataContext = myCollection ; } private void deleteItem() { myCollection.RemoveAt(0); //after removing I get error Which I guess should be something related //to interface update but I don't know how can I solve it } } Exception Detail : System.NullReferenceException was unhandled Message="Object reference not set to an instance of an object." Source="PresentationFramework" EDIT 3: I have a style which is for my treeitem to keep the treeitems expanded <Style TargetType="TreeViewItem"> <Setter Property="IsExpanded" Value="True" /> </Style> and with commenting this part I wont get any error !!! Now I want to change my question to why having this style is causing error ?

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