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  • How is the default constructor of System.Drawing.Graphics removed?

    - by Albert Iordache
    When I try to create an object of Graphics, why doesn't the following work? System.Drawing.Graphics graphicsObj = new System.Drawing.Graphics(); (I am aware that I could create a private System.Windows.Forms.Panel Obj; and then do CreateGraphics() if I wanted it to work) I tried to find a custom constructor for Graphics, but I couldn't find one. Where did Microsoft define it, or how did it block it?

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  • What does a static modifier on a constructor means?

    - by the_drow
    I saw this kind of code at work: class FooPlugin : IPlugin // IPlugin is a Microsoft CRM component, it has something special about it's execution { static FooPlugin() { SomeObject.StaticFunction(); // The guy who wrote it said it's meaningful to this question but he can't remember why. } } Any idea what does a static modifier on a constructor mean and why in this case it is required?

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  • JavaScript inheritance extend function

    - by Zach
    I'm having some trouble understanding the IF clause at the end of this function from Pro JavaScript Design Patterns: function extend(subClass, superClass) { var F = function() {}; F.prototype = superClass.prototype; subClass.prototype = new F(); subClass.prototype.constructor = subClass; subClass.superclass = superClass.prototype; if(superClass.prototype.constructor == Object.prototype.constructor) { superClass.prototype.constructor = superClass; } } The book explains that these lines ensure that the superclass's constructor attribute is correctly set, even if the superclass is the Object class itself. Yet, if I omit those three lines and do the following: function SubClass() {}; extend(SubClass, Object); alert(Object.prototype.constructor == Object); The alert says 'true', which means the superclass's constructor is set correctly even without those last three lines. Under what conditions, then, does this IF statement do something useful? Thanks.

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  • readonly keyword

    - by nmarun
    This is something new that I learned about the readonly keyword. Have a look at the following class: 1: public class MyClass 2: { 3: public string Name { get; set; } 4: public int Age { get; set; } 5:  6: private readonly double Delta; 7:  8: public MyClass() 9: { 10: Initializer(); 11: } 12:  13: public MyClass(string name = "", int age = 0) 14: { 15: Name = name; 16: Age = age; 17: Initializer(); 18: } 19:  20: private void Initializer() 21: { 22: Delta = 0.2; 23: } 24: } I have a couple of public properties and a private readonly member. There are two constructors – one that doesn’t take any parameters and the other takes two parameters to initialize the public properties. I’m also calling the Initializer method in both constructors to initialize the readonly member. Now when I build this, the code breaks and the Error window says: “A readonly field cannot be assigned to (except in a constructor or a variable initializer)” Two things after I read this message: It’s such a negative statement. I’d prefer something like: “A readonly field can be assigned to (or initialized) only in a constructor or through a variable initializer” But in my defense, I AM assigning it in a constructor (only indirectly). All I’m doing is creating a method that does it and calling it in a constructor. Turns out, .net was not ‘frameworked’ this way. We need to have the member initialized directly in the constructor. If you have multiple constructors, you can just use the ‘this’ keyword on all except the default constructors to call the default constructor. This default constructor can then initialize your readonly members. This will ensure you’re not repeating the code in multiple places. A snippet of what I’m talking can be seen below: 1: public class Person 2: { 3: public int UniqueNumber { get; set; } 4: public string Name { get; set; } 5: public int Age { get; set; } 6: public DateTime DateOfBirth { get; set; } 7: public string InvoiceNumber { get; set; } 8:  9: private readonly string Alpha; 10: private readonly int Beta; 11: private readonly double Delta; 12: private readonly double Gamma; 13:  14: public Person() 15: { 16: Alpha = "FDSA"; 17: Beta = 2; 18: Delta = 3.0; 19: Gamma = 0.0989; 20: } 21:  22: public Person(int uniqueNumber) : this() 23: { 24: UniqueNumber = uniqueNumber; 25: } 26: } See the syntax in line 22 and you’ll know what I’m talking about. So the default constructor gets called before the one in line 22. These are known as constructor initializers and they allow one constructor to call another. The other ‘myth’ I had about readonly members is that you can set it’s value only once. This was busted as well (I recall Adam and Jamie’s show). Say you’ve initialized the readonly member through a variable initializer. You can over-write this value in any of the constructors any number of times. 1: public class Person 2: { 3: public int UniqueNumber { get; set; } 4: public string Name { get; set; } 5: public int Age { get; set; } 6: public DateTime DateOfBirth { get; set; } 7: public string InvoiceNumber { get; set; } 8:  9: private readonly string Alpha = "asdf"; 10: private readonly int Beta = 15; 11: private readonly double Delta = 0.077; 12: private readonly double Gamma = 1.0; 13:  14: public Person() 15: { 16: Alpha = "FDSA"; 17: Beta = 2; 18: Delta = 3.0; 19: Gamma = 0.0989; 20: } 21:  22: public Person(int uniqueNumber) : this() 23: { 24: UniqueNumber = uniqueNumber; 25: Beta = 3; 26: } 27:  28: public Person(string name, DateTime dob) : this() 29: { 30: Name = name; 31: DateOfBirth = dob; 32:  33: Alpha = ";LKJ"; 34: Gamma = 0.0898; 35: } 36:  37: public Person(int uniqueNumber, string name, int age, DateTime dob, string invoiceNumber) : this() 38: { 39: UniqueNumber = uniqueNumber; 40: Name = name; 41: Age = age; 42: DateOfBirth = dob; 43: InvoiceNumber = invoiceNumber; 44:  45: Alpha = "QWER"; 46: Beta = 5; 47: Delta = 1.0; 48: Gamma = 0.0; 49: } 50: } In the above example, every constructor over-writes the values for the readonly members. This is perfectly valid. There is a possibility that based on the way the object is instantiated, the readonly member will have a different value. Well, that’s all I have for today and read this as it’s on a related topic.

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  • How to create a simple adf dashboard application with EJB 3.0

    - by Rodrigues, Raphael
    In this month's Oracle Magazine, Frank Nimphius wrote a very good article about an Oracle ADF Faces dashboard application to support persistent user personalization. You can read this entire article clicking here. The idea in this article is to extend the dashboard application. My idea here is to create a similar dashboard application, but instead ADF BC model layer, I'm intending to use EJB3.0. There are just a one small trick here and I'll show you. I'm using the HR usual oracle schema. The steps are: 1. Create a ADF Fusion Application with EJB as a layer model 2. Generate the entities from table (I'm using Department and Employees only) 3. Create a new Session Bean. I called it: HRSessionEJB 4. Create a new method like that: public List getAllDepartmentsHavingEmployees(){ JpaEntityManager jpaEntityManager = (JpaEntityManager)em.getDelegate(); Query query = jpaEntityManager.createNamedQuery("Departments.allDepartmentsHavingEmployees"); JavaBeanResult.setQueryResultClass(query, AggregatedDepartment.class); return query.getResultList(); } 5. In the Departments entity, create a new native query annotation: @Entity @NamedQueries( { @NamedQuery(name = "Departments.findAll", query = "select o from Departments o") }) @NamedNativeQueries({ @NamedNativeQuery(name="Departments.allDepartmentsHavingEmployees", query = "select e.department_id, d.department_name , sum(e.salary), avg(e.salary) , max(e.salary), min(e.salary) from departments d , employees e where d.department_id = e.department_id group by e.department_id, d.department_name")}) public class Departments implements Serializable {...} 6. Create a new POJO called AggregatedDepartment: package oramag.sample.dashboard.model; import java.io.Serializable; import java.math.BigDecimal; public class AggregatedDepartment implements Serializable{ @SuppressWarnings("compatibility:5167698678781240729") private static final long serialVersionUID = 1L; private BigDecimal departmentId; private String departmentName; private BigDecimal sum; private BigDecimal avg; private BigDecimal max; private BigDecimal min; public AggregatedDepartment() { super(); } public AggregatedDepartment(BigDecimal departmentId, String departmentName, BigDecimal sum, BigDecimal avg, BigDecimal max, BigDecimal min) { super(); this.departmentId = departmentId; this.departmentName = departmentName; this.sum = sum; this.avg = avg; this.max = max; this.min = min; } public void setDepartmentId(BigDecimal departmentId) { this.departmentId = departmentId; } public BigDecimal getDepartmentId() { return departmentId; } public void setDepartmentName(String departmentName) { this.departmentName = departmentName; } public String getDepartmentName() { return departmentName; } public void setSum(BigDecimal sum) { this.sum = sum; } public BigDecimal getSum() { return sum; } public void setAvg(BigDecimal avg) { this.avg = avg; } public BigDecimal getAvg() { return avg; } public void setMax(BigDecimal max) { this.max = max; } public BigDecimal getMax() { return max; } public void setMin(BigDecimal min) { this.min = min; } public BigDecimal getMin() { return min; } } 7. Create the util java class called JavaBeanResult. The function of this class is to configure a native SQL query to return POJOs in a single line of code using the utility class. Credits: http://onpersistence.blogspot.com.br/2010/07/eclipselink-jpa-native-constructor.html package oramag.sample.dashboard.model.util; /******************************************************************************* * Copyright (c) 2010 Oracle. All rights reserved. * This program and the accompanying materials are made available under the * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0 * which accompanies this distribution. * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html * and the Eclipse Distribution License is available at * http://www.eclipse.org/org/documents/edl-v10.php. * * @author shsmith ******************************************************************************/ import java.lang.reflect.Constructor; import java.lang.reflect.InvocationTargetException; import java.util.ArrayList; import java.util.List; import javax.persistence.Query; import org.eclipse.persistence.exceptions.ConversionException; import org.eclipse.persistence.internal.helper.ConversionManager; import org.eclipse.persistence.internal.sessions.AbstractRecord; import org.eclipse.persistence.internal.sessions.AbstractSession; import org.eclipse.persistence.jpa.JpaHelper; import org.eclipse.persistence.queries.DatabaseQuery; import org.eclipse.persistence.queries.QueryRedirector; import org.eclipse.persistence.sessions.Record; import org.eclipse.persistence.sessions.Session; /*** * This class is a simple query redirector that intercepts the result of a * native query and builds an instance of the specified JavaBean class from each * result row. The order of the selected columns musts match the JavaBean class * constructor arguments order. * * To configure a JavaBeanResult on a native SQL query use: * JavaBeanResult.setQueryResultClass(query, SomeBeanClass.class); * where query is either a JPA SQL Query or native EclipseLink DatabaseQuery. * * @author shsmith * */ public final class JavaBeanResult implements QueryRedirector { private static final long serialVersionUID = 3025874987115503731L; protected Class resultClass; public static void setQueryResultClass(Query query, Class resultClass) { JavaBeanResult javaBeanResult = new JavaBeanResult(resultClass); DatabaseQuery databaseQuery = JpaHelper.getDatabaseQuery(query); databaseQuery.setRedirector(javaBeanResult); } public static void setQueryResultClass(DatabaseQuery query, Class resultClass) { JavaBeanResult javaBeanResult = new JavaBeanResult(resultClass); query.setRedirector(javaBeanResult); } protected JavaBeanResult(Class resultClass) { this.resultClass = resultClass; } @SuppressWarnings("unchecked") public Object invokeQuery(DatabaseQuery query, Record arguments, Session session) { List results = new ArrayList(); try { Constructor[] constructors = resultClass.getDeclaredConstructors(); Constructor javaBeanClassConstructor = null; // (Constructor) resultClass.getDeclaredConstructors()[0]; Class[] constructorParameterTypes = null; // javaBeanClassConstructor.getParameterTypes(); List rows = (List) query.execute( (AbstractSession) session, (AbstractRecord) arguments); for (Object[] columns : rows) { boolean found = false; for (Constructor constructor : constructors) { javaBeanClassConstructor = constructor; constructorParameterTypes = javaBeanClassConstructor.getParameterTypes(); if (columns.length == constructorParameterTypes.length) { found = true; break; } // if (columns.length != constructorParameterTypes.length) { // throw new ColumnParameterNumberMismatchException( // resultClass); // } } if (!found) throw new ColumnParameterNumberMismatchException( resultClass); Object[] constructorArgs = new Object[constructorParameterTypes.length]; for (int j = 0; j < columns.length; j++) { Object columnValue = columns[j]; Class parameterType = constructorParameterTypes[j]; // convert the column value to the correct type--if possible constructorArgs[j] = ConversionManager.getDefaultManager() .convertObject(columnValue, parameterType); } results.add(javaBeanClassConstructor.newInstance(constructorArgs)); } } catch (ConversionException e) { throw new ColumnParameterMismatchException(e); } catch (IllegalArgumentException e) { throw new ColumnParameterMismatchException(e); } catch (InstantiationException e) { throw new ColumnParameterMismatchException(e); } catch (IllegalAccessException e) { throw new ColumnParameterMismatchException(e); } catch (InvocationTargetException e) { throw new ColumnParameterMismatchException(e); } return results; } public final class ColumnParameterMismatchException extends RuntimeException { private static final long serialVersionUID = 4752000720859502868L; public ColumnParameterMismatchException(Throwable t) { super( "Exception while processing query results-ensure column order matches constructor parameter order", t); } } public final class ColumnParameterNumberMismatchException extends RuntimeException { private static final long serialVersionUID = 1776794744797667755L; public ColumnParameterNumberMismatchException(Class clazz) { super( "Number of selected columns does not match number of constructor arguments for: " + clazz.getName()); } } } 8. Create the DataControl and a jsf or jspx page 9. Drag allDepartmentsHavingEmployees from DataControl and drop in your page 10. Choose Graph > Type: Bar (Normal) > any layout 11. In the wizard screen, Bars label, adds: sum, avg, max, min. In the X Axis label, adds: departmentName, and click in OK button 12. Run the page, the result is showed below: You can download the workspace here . It was using the latest jdeveloper version 11.1.2.2.

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  • FTP could not connect after applying local DNS(private DNS)

    - by Rahul
    I made a software router in CentOS linux and in that made a DNS server. I am using centOS 6..4 for making DNS i applied following steps: changed the host name = abc.zoom.com and domain name = zoom.com. then did changes in the named.rfc.1912 file as per rename named.localhost = forward and named.loopback = reverse in forward lookups i changed zone "zoom.com" IN { type master; file "forward"; allow-update { none; }; and in reverse lookups i changed zone "x.168.192.in-addr.arpa" IN { type master; file "reverse"; allow-update { none; }; and then did changes in the named.conf file options { listen-on port 53 {192.168.x.x;}; listen-on-v6 port 53 { ::1; }; directory "/var/named"; dump-file "/var/named/data/cache_dump.db"; statistics-file "/var/named/data/named_stats.txt"; memstatistics-file "/var/named/data/named_mem_stats.txt"; allow-query {any;}; recursion yes; 192.168.x.x is my local DNS address. then i copied lookups file in /var/named and edited the file "forward" $TTL 1D @ IN SOA abc.zoom.com. rahul.abc.zoom.com. ( 0 ; serial 1D ; refresh 1H ; retry 1W ; expire 3H ) ; minimum NS abc.zoom.com. abc A 192.168.x.x and for " reverse" $TTL 1D @ IN SOA abc.zoom.com. rahul.abc.zoom.com.( 0 ; serial 1D ; refresh 1H ; retry 1W ; expire 3H ) ; minimum NS abc.zoom.com. x PTR abc.zoom.com. when i put the public ip details in the Eth0 it was automatically redirect in to the resolve.conf when i checked through dig command the answer, query all were 1. my system is itself a Software router.In gateway of my all local machine i give my system ip address. however my DNS and Gateway IP is same. Now the problem is that. i gave the static ips to all my local machines when i give the DNS which i made i.e 192.168.x.x that time my ftp is not connect in filezilla software E.g: host : pqr.zoom.com ("zoom.com" is my local domain name) username : pqr password : pqr gives an error: Error: Connection timed out Error: Could not connect to server but if i give the public DNS address it get connected. i want to solve this problem please give solution on this.

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  • JavaScript Class Patterns Revisited: Endgame

    - by Liam McLennan
    I recently described some of the patterns used to simulate classes (types) in JavaScript. But I missed the best pattern of them all. I described a pattern I called constructor function with a prototype that looks like this: function Person(name, age) { this.name = name; this.age = age; } Person.prototype = { toString: function() { return this.name + " is " + this.age + " years old."; } }; var john = new Person("John Galt", 50); console.log(john.toString()); and I mentioned that the problem with this pattern is that it does not provide any encapsulation, that is, it does not allow private variables. Jan Van Ryswyck recently posted the solution, obvious in hindsight, of wrapping the constructor function in another function, thereby allowing private variables through closure. The above example becomes: var Person = (function() { // private variables go here var name,age; function constructor(n, a) { name = n; age = a; } constructor.prototype = { toString: function() { return name + " is " + age + " years old."; } }; return constructor; })(); var john = new Person("John Galt", 50); console.log(john.toString()); Now we have prototypal inheritance and encapsulation. The important thing to understand is that the constructor, and the toString function both have access to the name and age private variables because they are in an outer scope and they become part of the closure.

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  • TypeError: Error #1007: Instantiation attempted on a non-constructor. on port to Flex 4

    - by Josh Handel
    I have been porting an app from Flex 3.4.x to 4.0.. I have successfully ported the app and its libraries to flex 4.0, I've also removed ALL the references to http://www.adobe.com/2006/flex/mx in any of my mxml files... In short I "think" I have moved everything over to the new mx framework (2009).. But I still get the following error (which never happend in 3.4 or 3.5 with this same app) when I try to run my flex app. TypeError: Error #1007: Instantiation attempted on a non-constructor. at mx.preloaders::Preloader/initialize()[E:\dev\4.0.0\frameworks\projects\framework\src\mx\preloaders\Preloader.as:253] at mx.managers::SystemManager/http://www.adobe.com/2006/flex/mx/internal::initialize()[E:\dev\4.0.0\frameworks\projects\framework\src\mx\managers\SystemManager.as:1925] at mx.managers::SystemManager/initHandler()[E:\dev\4.0.0\frameworks\projects\framework\src\mx\managers\SystemManager.as:2419] At this point I am completely stumped.. anyone have any ideas? Thanks

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  • Can I pass constructor parameters to Unity's Resolve() method?

    - by NotDan
    I am using Microsoft's Unity for dependency injection and I want to do something like this: IDataContext context = _unityContainer.Resolve<IDataContext>(); var repositoryA = _unityContainer.Resolve<IRepositoryA>(context); //Same instance of context var repositoryB = _unityContainer.Resolve<IRepositoryB>(context); //Same instance of context IDataContext context2 = _unityContainer.Resolve<IDataContext>(); //New instance var repositoryA2 = _unityContainer.Resolve<IRepositoryA>(context2); RepositoryA and RepositoryB both have a constructor that takes an IDataContext parameter, and I want Unity to initialize the repository with the context that I pass it. Also note that IDataContext is not registered with Unity (I dont want 3 instances of IDataContext).

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  • Java: how to initialize private final int value with if-else in constructor?

    - by HH
    $ javac InitInt.java InitInt.java:7: variable right might not have been initialized InitInt(){} ^ 1 error $ cat InitInt.java import java.util.*; import java.io.*; public class InitInt { private final int right; InitInt(){} public static void main(String[] args) { // I don't want to assign any value. // just initialize it, how? InitInt test = new InitInt(); System.out.println(test.getRight()); // later assiging a value } public int getRight(){return right;} } Initialization problem with Constructor, due to if-else -loop InitInt{ // Still the error, "may not be initialized" // How to initialise it, without removing if-else? if(snippetBuilder.length()>(charwisePos+25)){ right=charwisePos+25; }else{ right=snippetBuilder.length()-1; } }

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  • Overriding Page class constructor in ASP.NET code-behind file -- when is it called?

    - by CSharp Noob
    If I override the System.Web.UI.Page constructor, as shown, when does DoSomething() get called in terms of the page lifecycle? I can't seem to find this documented anywhere. namespace NameSpace1 { public partial class MyClass : System.Web.UI.Page { public MyClass() { DoSomething(); } protected void Page_Load(object sender, EventArgs e) { } } } For reference, here is the ASP.NET Page Lifecycle Overview: http://msdn.microsoft.com/en-us/library/ms178472.aspx Turns out the best answer was right in the MSDN article. I just had to look carefully at the diagram.

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  • Is there a pattern that allows a constructor to be called only from a specific factory and from nowh

    - by willem
    We have a class, say LegacyUserSettingsService. LegacyUserSettingsService implements an interface, IUserSettingsService. You can get an instance of the IUserSettingsService by calling our ApplicationServicesFactory. The factory uses Spring.NET to construct the concrete LegacyUserSettingsService. The trouble is that new developers sometimes do their own thing and construct new instances of the LegacyUserSettingsService directly (instead of going via the factory). Is there a way to protect the constructor of the concrete class so it can only be called from the factory? A well-known pattern perhaps? Note that the concrete class resides in a different assembly (separate from the Factory's assembly, so the internal keyword is not a solution). The factory assembly references the other assembly that contains the concrete class. Any ideas?

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  • Best way to insert items from a Derived class's constructor into a Base class's private std::vector?

    - by Will
    I have these classes: class Base { ... private: std::vector<X> v; }; class Derived { Derived(X*, int n); } where the constructor of Derived is passed an array of item Xs, which I need to insert into my vector v in the Base class. (X is a smart pointer) Currently I see two ways to do this: 1) Create a function in Base: InsertItem(X*) that will insert an item into the vector. 2) Create a vector in Derived that contains the full list, then get it into Base by moving the entire vector. I dont see any advantages to #2, but was wondering if #1 was a good solution, or if there are better ways to do this. Thanks!

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  • How to define a static array without a contant size in a constructor of a class? (C++)

    - by Keand64
    I have a class defined as: class Obj { public: int width, height; Obj(int w, int h); } and I need it to contain a static array like so: int presc[width][height]; however, I cannot define within the class, so it it possible to create a pointer to a 2D array (and, out of curiosity, 3, 4, and 5D arrays), have that as a member of the class, and intitalize it in the constructor like: int ar[5][6]; Obj o(5, 6, &ar); If that isn't possible, is there any way to get a static array without a contant size in a class, or am I going to have to use a dynamic array? (Something I don't want to do because I don't plan on ever changing the size of the array after it's created.)

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  • Why does jQuery do this in its constructor function implementation?

    - by mattcodes
    If we look at the latest jQuery source at http://code.jquery.com/jquery-latest.js we see the following: var jQuery = function( selector, context ) { // The jQuery object is actually just the init constructor 'enhanced' return new jQuery.fn.init( selector, context ); } My understanding of the new keyword in Javascript is essentially JavaScript passes the function an empty object {} and the function sets stuff on it via this.blah. Also from my understanding new differs from .call/.apply etc.. in that the return object also has the prototype set to that of the function. So the return value should have a prototype that the same as jQuery.prototype.init.prototype (or jQuery.fn.init.prototype). However from what I see its prototype is set to jQuery.prototype thus all the commands available to work on the set. Why is this? What am I missing in my understanding?

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  • ASP.NET MVC View Not posting back to Post method and expecting a parameterless Constructor?

    - by VJ
    Hi, I am trying to post back some data using a viewmodel i have created and it works for me for one of the projects.But I am doin this right now public ActionResult Foo(string userkey) { vm.Value="Xvalue"; return View(vm); } [HttpPost] public ActionResult Foo( MyViewModel vm) { // process input if (inputOK) string value=vm.Value return RedirectToAction("Index"); return View(); } public class MyViewModel { public string Value { get; set; } public SomeClass newobj {get;set;} } public class SomeClass { public int id{get;set;} public string str{get;set;} } So it on debugging never goes into the parameter method for Post although on the view i have added a form and a button that submits and the page inherits from the viewmodel.I get an error saying it expects a parameterless constructor how do I fix this ? . I wrote an post method with no parameters and it does go into that method

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  • C#, Can I move dictionary initial code out from the constructor?

    - by 5YrsLaterDBA
    Here is my code right now. But I would like to move those "Add" out from the constructor. Can we initialize Dictionary when we new it? or you have another better idea. Basically I want to define few characters which are used in many places. public class User { public enum actionEnum { In, Out, Fail } public static Dictionary<actionEnum, String> loginAction = new Dictionary<actionEnum, string>(); public User() { loginAction.Add(actionEnum.In, "I"); loginAction.Add(actionEnum.Out, "O"); loginAction.Add(actionEnum.Fail, "F"); } ..... }

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  • will destroyed() be emitted if the constructor of a class derived from QObject throws?

    - by PorkyBrain
    Ive seen Qt GUI syntax like the following all over the place: myDialog::myDialog(QWidget *parent, Qt::WFlags flags):QDialog(parent, flags) { QPushButton *button = new QPushButton("&Download", this); QVBoxLayout *layout = new QVBoxLayout(this); //something that can throw here layout ->addWidget(button ); setLayout(layout); } I've always wondered if this can leak in the event of an exception because the "this" I'm giving as a parent to button and layout is not fully constructed so it might not destroy its children. I tried it out in MSVC2010 Qt4.8.3 and it looks like as soon as the base QObject class is fully created (which is done first of course) it is ok to pass "this" to other objects in the constructor, they will destroyed correctly. I haven't found the spot in the Qt docs guaranteeing this though, can someone point me to it so I have assurance that this will not change in the future?

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  • why can not create instance from any class out side of constructor?

    - by Phsika
    why i generate instance outside of class. i give inheritance snifC to sinifD i need to create instance sinifC sinifc= new sinifC() in SinifD out side of constructor? public class sinifC { public void method3() { Console.WriteLine("Deneme3"); } } public class sinifD : sinifC { void method4() { Console.WriteLine("Deneme4"); } public sinifD() { sinifC sinifc = new sinifC(); sinifc.method3(); } } i want to make it below: public class sinifC { public void method3() { Console.WriteLine("Deneme3"); } } public class sinifD : sinifC { void method4() { Console.WriteLine("Deneme4"); } sinifC sinifc = new sinifC(); sinifc.method3(); } Error: Invalid token '(' in class, struct, or interface member declaration

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  • Spring security ldap authentication with different ldap for authorities

    - by wuntee
    I am trying to set up an ldap authentication context where the authorities is a separate ldap instance (with the same principal name). I am having trouble setting up the authentication part, the logs dont show any search results for the following context. Can anyone see what I am doing wrong? <beans:bean id="ldapAuthProvider" class="org.springframework.security.ldap.authentication.LdapAuthenticationProvider"> <beans:constructor-arg> <beans:bean class="org.springframework.security.ldap.authentication.BindAuthenticator"> <beans:constructor-arg ref="adContextSource" /> <beans:property name="userSearch"> <beans:bean class="org.springframework.security.ldap.search.FilterBasedLdapUserSearch"> <beans:constructor-arg index="0" value=""/> <beans:constructor-arg index="1" value="(samaccountname={0})"/> <beans:constructor-arg index="2" ref="adContextSource" /> <beans:property name="searchSubtree" value="true" /> <beans:property name="returningAttributes"> <beans:list> <beans:value>DN</beans:value> </beans:list> </beans:property> </beans:bean> </beans:property> </beans:bean> </beans:constructor-arg> <beans:constructor-arg> <beans:bean class="org.springframework.security.ldap.userdetails.DefaultLdapAuthoritiesPopulator"> <beans:constructor-arg ref="cadaContextSource" /> <beans:constructor-arg value="ou=groups" /> <beans:property name="groupRoleAttribute" value="cn" /> </beans:bean> </beans:constructor-arg> </beans:bean> The logs simply show this when trying to authenticate: [DEBUG,UsernamePasswordAuthenticationFilter] Request is to process authentication [DEBUG,ProviderManager] Authentication attempt using org.springframework.security.ldap.authentication.LdapAuthenticationProvider [DEBUG,LdapAuthenticationProvider] Processing authentication request for user: wuntee [DEBUG,FilterBasedLdapUserSearch] Searching for user 'wuntee', with user search [ searchFilter: '(samaccountname={0})', searchBase: '', scope: subtree, searchTimeLimit: 0, derefLinkFlag: false ] [DEBUG,AbstractContextSource] Got Ldap context on server 'ldap://adapps.cable.comcast.com:3268/dc=comcast,dc=com/dc=comcast,dc=com' [DEBUG,XmlWebApplicationContext] Publishing event in Root WebApplicationContext: org.springframework.security.authentication.event.AuthenticationFailureServiceExceptionEvent[source=org.springframework.security.authentication.UsernamePasswordAuthenticationToken@b777617d: Principal: wuntee; Password: [PROTECTED]; Authenticated: false; Details: org.springframework.security.web.authentication.WebAuthenticationDetails@12afc: RemoteIpAddress: 127.0.0.1; SessionId: 191F70ED4E8351F8638868C34C6A076A; Not granted any authorities] [DEBUG,DefaultListableBeanFactory] Returning cached instance of singleton bean 'org.springframework.security.core.session.SessionRegistryImpl#0' [DEBUG,UsernamePasswordAuthenticationFilter] Authentication request failed: org.springframework.security.authentication.AuthenticationServiceException: Failed to parse DN; nested exception is org.springframework.ldap.core.TokenMgrError: Lexical error at line 1, column 21. Encountered: "=" (61), after : "" [DEBUG,UsernamePasswordAuthenticationFilter] Updated SecurityContextHolder to contain null Authentication [DEBUG,UsernamePasswordAuthenticationFilter] Delegating to authentication failure handlerorg.springframework.security.web.authentication.SimpleUrlAuthenticationFailureHandler@28651c

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  • JPA Entity Manager resource handling

    - by chiragshahkapadia
    Every time I call JPA method its creating entity and binding query. My persistence properties are: <property name="hibernate.dialect" value="org.hibernate.dialect.Oracle10gDialect"/> <property name="hibernate.cache.provider_class" value="net.sf.ehcache.hibernate.SingletonEhCacheProvider"/> <property name="hibernate.cache.use_second_level_cache" value="true"/> <property name="hibernate.cache.use_query_cache" value="true"/> And I am creating entity manager the way shown below: emf = Persistence.createEntityManagerFactory("pu"); em = emf.createEntityManager(); em = Persistence.createEntityManagerFactory("pu").createEntityManager(); Is there any nice way to manage entity manager resource instead create new every time or any property can set in persistence. Remember it's JPA. See below binding log every time : 15:35:15,527 INFO [AnnotationBinder] Binding entity from annotated class: * 15:35:15,527 INFO [QueryBinder] Binding Named query: * = * 15:35:15,527 INFO [QueryBinder] Binding Named query: * = * 15:35:15,527 INFO [QueryBinder] Binding Named query: 15:35:15,527 INFO [QueryBinder] Binding Named query: 15:35:15,527 INFO [QueryBinder] Binding Named query: 15:35:15,527 INFO [QueryBinder] Binding Named query: 15:35:15,527 INFO [QueryBinder] Binding Named query: 15:35:15,527 INFO [QueryBinder] Binding Named query: 15:35:15,527 INFO [QueryBinder] Binding Named query: 15:35:15,527 INFO [EntityBinder] Bind entity com.* on table * 15:35:15,542 INFO [HibernateSearchEventListenerRegister] Unable to find org.hibernate.search.event.FullTextIndexEventListener on the classpath. Hibernate Search is not enabled. 15:35:15,542 INFO [NamingHelper] JNDI InitialContext properties:{} 15:35:15,542 INFO [DatasourceConnectionProvider] Using datasource: 15:35:15,542 INFO [SettingsFactory] RDBMS: and Real Application Testing options 15:35:15,542 INFO [SettingsFactory] JDBC driver: Oracle JDBC driver, version: 9.2.0.1.0 15:35:15,542 INFO [Dialect] Using dialect: org.hibernate.dialect.Oracle10gDialect 15:35:15,542 INFO [TransactionFactoryFactory] Transaction strategy: org.hibernate.transaction.JDBCTransactionFactory 15:35:15,542 INFO [TransactionManagerLookupFactory] No TransactionManagerLookup configured (in JTA environment, use of read-write or transactional second-level cache is not recomm ended) 15:35:15,542 INFO [SettingsFactory] Automatic flush during beforeCompletion(): disabled 15:35:15,542 INFO [SettingsFactory] Automatic session close at end of transaction: disabled 15:35:15,542 INFO [SettingsFactory] JDBC batch size: 15 15:35:15,542 INFO [SettingsFactory] JDBC batch updates for versioned data: disabled 15:35:15,542 INFO [SettingsFactory] Scrollable result sets: enabled 15:35:15,542 INFO [SettingsFactory] JDBC3 getGeneratedKeys(): disabled 15:35:15,542 INFO [SettingsFactory] Connection release mode: auto 15:35:15,542 INFO [SettingsFactory] Default batch fetch size: 1 15:35:15,542 INFO [SettingsFactory] Generate SQL with comments: disabled 15:35:15,542 INFO [SettingsFactory] Order SQL updates by primary key: disabled 15:35:15,542 INFO [SettingsFactory] Order SQL inserts for batching: disabled 15:35:15,542 INFO [SettingsFactory] Query translator: org.hibernate.hql.ast.ASTQueryTranslatorFactory 15:35:15,542 INFO [ASTQueryTranslatorFactory] Using ASTQueryTranslatorFactory 15:35:15,542 INFO [SettingsFactory] Query language substitutions: {} 15:35:15,542 INFO [SettingsFactory] JPA-QL strict compliance: enabled 15:35:15,542 INFO [SettingsFactory] Second-level cache: enabled 15:35:15,542 INFO [SettingsFactory] Query cache: enabled 15:35:15,542 INFO [SettingsFactory] Cache region factory : org.hibernate.cache.impl.bridge.RegionFactoryCacheProviderBridge 15:35:15,542 INFO [RegionFactoryCacheProviderBridge] Cache provider: net.sf.ehcache.hibernate.SingletonEhCacheProvider 15:35:15,542 INFO [SettingsFactory] Optimize cache for minimal puts: disabled 15:35:15,542 INFO [SettingsFactory] Structured second-level cache entries: disabled 15:35:15,542 INFO [SettingsFactory] Query cache factory: org.hibernate.cache.StandardQueryCacheFactory 15:35:15,542 INFO [SettingsFactory] Statistics: disabled 15:35:15,542 INFO [SettingsFactory] Deleted entity synthetic identifier rollback: disabled 15:35:15,542 INFO [SettingsFactory] Default entity-mode: pojo 15:35:15,542 INFO [SettingsFactory] Named query checking : enabled 15:35:15,542 INFO [SessionFactoryImpl] building session factory 15:35:15,542 INFO [SessionFactoryObjectFactory] Not binding factory to JNDI, no JNDI name configured 15:35:15,542 INFO [UpdateTimestampsCache] starting update timestamps cache at region: org.hibernate.cache.UpdateTimestampsCache 15:35:15,542 INFO [StandardQueryCache] starting query cache at region: org.hibernate.cache.StandardQueryCache

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  • DNS request timed out. timeout was 2 seconds

    - by sahil007
    i had setup bind dns server on centos. from local lan it will work fine but from remote when i tried to nslookup ..it will give reply like "DNS request timed out...timeout was 2 seconds." what is the problem? this is my bind config---- // Red Hat BIND Configuration Tool options { directory "/var/named"; dump-file "/var/named/data/cache_dump.db"; statistics-file "/var/named/data/named_stats.txt"; query-source address * port 53; }; controls { inet 127.0.0.1 allow {localhost; } keys {rndckey; }; }; acl internals { 127.0.0.0/8; 192.168.0.0/24; 10.0.0.0/8; }; view "internal" { match-clients { internals; }; recursion yes; zone "mydomain.com" { type master; file "mydomain.com.zone"; }; zone "0.168.192.in-addr.arpa" { type master; file "0.168.192.in-addr.arpa.zone"; }; zone "." IN { type hint; file "named.root"; }; zone "localdomain." IN { type master; file "localdomain.zone"; allow-update { none; }; }; zone "localhost." IN { type master; file "localhost.zone"; allow-update { none; }; }; zone "0.0.127.in-addr.arpa." IN { type master; file "named.local"; allow-update { none; }; }; zone "0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa." I N { type master; file "named.ip6.local"; allow-update { none; }; }; zone "255.in-addr.arpa." IN { type master; file "named.broadcast"; allow-update { none; }; }; zone "0.in-addr.arpa." IN { type master; file "named.zero"; allow-update { none; }; }; }; view "external" { match-clients { any; }; recursion no; zone "mydomain.com" { type master; file "mydomain.com.zone"; // file "/var/named/chroot/var/named/mydomain.com.zone"; }; zone "0.168.192.in-addr.arpa" { type master; file "0.168.192.in-addr.arpa.zone"; }; }; include "/etc/rndc.key";

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  • How should an object that uses composition set its composed components?

    - by Casey
    After struggling with various problems and reading up on component-based systems and reading Bob Nystrom's excellent book "Game Programming Patterns" and in particular the chapter on Components I determined that this is a horrible idea: //Class intended to be inherited by all objects. Engine uses Objects exclusively. class Object : public IUpdatable, public IDrawable { public: Object(); Object(const Object& other); Object& operator=(const Object& rhs); virtual ~Object() =0; virtual void SetBody(const RigidBodyDef& body); virtual const RigidBody* GetBody() const; virtual RigidBody* GetBody(); //Inherited from IUpdatable virtual void Update(double deltaTime); //Inherited from IDrawable virtual void Draw(BITMAP* dest); protected: private: }; I'm attempting to refactor it into a more manageable system. Mr. Nystrom uses the constructor to set the individual components; CHANGING these components at run-time is impossible. It's intended to be derived and be used in derivative classes or factory methods where their constructors do not change at run-time. i.e. his Bjorne object is just a call to a factory method with a specific call to the GameObject constructor. Is this a good idea? Should the object have a default constructor and setters to facilitate run-time changes or no default constructor without setters and instead use a factory method? Given: class Object { public: //...See below for constructor implementation concerns. Object(const Object& other); Object& operator=(const Object& rhs); virtual ~Object() =0; //See below for Setter concerns IUpdatable* GetUpdater(); IDrawable* GetRenderer(); protected: IUpdatable* _updater; IDrawable* _renderer; private: }; Should the components be read-only and passed in to the constructor via: class Object { public: //No default constructor. Object(IUpdatable* updater, IDrawable* renderer); //...remainder is same as above... }; or Should a default constructor be provided and then the components can be set at run-time? class Object { public: Object(); //... SetUpdater(IUpdater* updater); SetRenderer(IDrawable* renderer); //...remainder is same as above... }; or both? class Object { public: Object(); Object(IUpdater* updater, IDrawable* renderer); //... SetUpdater(IUpdater* updater); SetRenderer(IDrawable* renderer); //...remainder is same as above... };

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  • Errors when trying to compile the driver for the rtl8192su wireless adapter

    - by Tom Brito
    I have a wireless to usb adapter, and I'm having some trouble to install the drivers on Ubuntu. First of all, the readme says to use the make command, and I already got errors: $ make make[1]: Entering directory `/usr/src/linux-headers-2.6.35-22-generic' CC [M] /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.o /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c: In function ‘rtl8192_usb_probe’: /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12325: error: ‘struct net_device’ has no member named ‘open’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12326: error: ‘struct net_device’ has no member named ‘stop’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12327: error: ‘struct net_device’ has no member named ‘tx_timeout’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12328: error: ‘struct net_device’ has no member named ‘do_ioctl’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12329: error: ‘struct net_device’ has no member named ‘set_multicast_list’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12330: error: ‘struct net_device’ has no member named ‘set_mac_address’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12331: error: ‘struct net_device’ has no member named ‘get_stats’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12332: error: ‘struct net_device’ has no member named ‘hard_start_xmit’ make[2]: *** [/home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.o] Error 1 make[1]: *** [_module_/home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u] Error 2 make[1]: Leaving directory `/usr/src/linux-headers-2.6.35-22-generic' make: *** [all] Error 2 /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/ is the path where I copied the drivers on my computer. Any idea how to solve this? (I don't even know what the error is...) update: sudo lshw -class network *-network description: Ethernet interface product: RTL8111/8168B PCI Express Gigabit Ethernet controller vendor: Realtek Semiconductor Co., Ltd. physical id: 0 bus info: pci@0000:01:00.0 logical name: eth0 version: 03 serial: 78:e3:b5:e7:5f:6e size: 10MB/s capacity: 1GB/s width: 64 bits clock: 33MHz capabilities: pm msi pciexpress msix vpd bus_master cap_list rom ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=half latency=0 link=no multicast=yes port=MII speed=10MB/s resources: irq:42 ioport:d800(size=256) memory:fbeff000-fbefffff memory:faffc000-faffffff memory:fbec0000-fbedffff *-network DISABLED description: Wireless interface physical id: 2 logical name: wlan0 serial: 00:26:18:a1:ae:64 capabilities: ethernet physical wireless configuration: broadcast=yes multicast=yes wireless=802.11b/g sudo lspci 00:00.0 Host bridge: Intel Corporation Core Processor DRAM Controller (rev 18) 00:02.0 VGA compatible controller: Intel Corporation Core Processor Integrated Graphics Controller (rev 18) 00:16.0 Communication controller: Intel Corporation 5 Series/3400 Series Chipset HECI Controller (rev 06) 00:1a.0 USB Controller: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller (rev 06) 00:1b.0 Audio device: Intel Corporation 5 Series/3400 Series Chipset High Definition Audio (rev 06) 00:1c.0 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 1 (rev 06) 00:1c.2 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 3 (rev 06) 00:1d.0 USB Controller: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller (rev 06) 00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev a6) 00:1f.0 ISA bridge: Intel Corporation 5 Series Chipset LPC Interface Controller (rev 06) 00:1f.2 SATA controller: Intel Corporation 5 Series/3400 Series Chipset 6 port SATA AHCI Controller (rev 06) 00:1f.3 SMBus: Intel Corporation 5 Series/3400 Series Chipset SMBus Controller (rev 06) 01:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 03) 02:00.0 FireWire (IEEE 1394): VIA Technologies, Inc. VT6315 Series Firewire Controller (rev 01) sudo lsusb Bus 002 Device 003: ID 0bda:0158 Realtek Semiconductor Corp. USB 2.0 multicard reader Bus 002 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 001 Device 004: ID 045e:00f9 Microsoft Corp. Wireless Desktop Receiver 3.1 Bus 001 Device 003: ID 0b05:1786 ASUSTek Computer, Inc. Bus 001 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

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