Web Service Constructor error
Dear All, When I'm adding a default constructor to my ASP.NET web service I get a server error when calling a web method, but it works fine when I remove that constructor. Can you explain? ...
constructor
What is the full list of actions performed by placement new in C++?
In this question creating a factory method when the compiler doesn't support new and placement new is discussed. Obviously some suitable solution could be crafted using malloc() if all necessary steps done by placement new are reproduced in some way. What does placement new do - I'll try to list and hope not to miss anything - except th...
Parameterized Constructor Cascading
Consider the following situation class URISplit { var $REQ_URI; //some more variables function __construct($uri) { //some code $this->REQ_URI = $uri; //some code yet again } } and the following class URIResolve extends URISplit { //some variables function __construct($uri) { ...
What are practical uses of a protected constructor?
Why would anyone declare a constructor protected? I know that constructors are declared private for the purpose of not allowing their creation on stack. ...
CA1062: ValidateArgumentsOfPublicMethods on co-constructor calls
I have a class with two constructors that look like this: public MyClass(SomeOtherClass source) : this(source, source.Name) { } public MyClass(SomeOtherClass source, string name) { /* ... */ } When I run FxCop, it correctly reports a violation of CA1062: ValidateArgumentsOfPublicMethods, because if source is null in the first construc...
Passing information to a constructor without using a parameter in C#
I have backed myself into a a bit of a corner. Here is a simplified version of what I have (in C#): class OuterClass { private class BadClass { private int Data; public BadClass() { Data = 0; ... } } T Build<T>(Object Input) { T x = new T(); ...
C++ - Calling a function inside a class with the same name as the class
I was trying to write up a class in c++, and I came across a rather odd problem: calling outside functions inside of a class that have the same name as the class. It's kinda confusing, so here's an example: void A(char* D) { printf(D); } class A { public: A(int B); void C(); }; A::A(int B) { // something here } void A::C() {...
How do I make a generic class to represent a range using .NET?
I've been trying to make a generic class to represent a range of values but am having some difficulty trying to work out what I'm missing (the compiler comlplains about a missing copy constructor, but all the implementations I've tried have failed). So my questions: Is there a Range template somewhere I've missed to avoid me reinventin...
Correct way to initialize an object with exception throwing constructor
Hi, This seems to be a trivial question but I got hung on it for a few hours now (maybe too much Java killed my C++ braincells). I have created a class that has the following constructor (i.e. no default constructor) VACaptureSource::VACaptureSource( std::string inputType, std::string inputLocation ) { if( type == "" || location =...
DataContractSerializer doesn't call my constructor ??
I just realized something crazy, which I assumed to be completely impossible : when deserializing an object, the DataContractSerializer doesn't call the constructor ! Take this class, for instance : [DataContract] public class Book { public Book() { // breakpoint here } [DataMember(Order = 0)] public string Title {...
How do you Specify a Method to be a Destructor Rather than a Constructor in C++?
How do you specify a method to be a destructor rather than a constructor in C++? This confuses me very much. I can't tell the difference between the two. ...
Protected Constructors and MustInherit/ Abstract class
What is the difference between a class with protected constructors and a class marked as MustInherit? (I'm programming in VB.Net but it probably equally applies to c#). The reason I ask is because I have an abstract class that I want to convert the constructors to shared/static methods. (To add some constraints). I can't do this becaus...
How to override ObjectOutputStream.writeStreamHeader()?
The method ObjectOutputStream.writeStreamHeader() can be overridden to prepend or append data to the header. However, if that data is based on an argument passed to the derived class's constructor like: public class MyObjectOutputStream extends ObjectOutputStream { public MyObjectOutputStream( int myData, OutputStream out ) throws...
Is it possible to make creation of different classes controllable by configurations?
Is it possible at all to control the creation of different classes from configurations? Say, I have a function which does this which is hard-coded: BaseClass* getClassObject(int type) { switch (type) { case 1: return new DerivedClass1(); case 2: return new DerivedClass2(); default: return 0; ...
Passing a dynamic attribute to an internal constructor
Calling an internal constructor with a dynamic argument in C# 4.0b results in the following exception System.ArgumentNullException: Value cannot be null. Parameter name: constructor Example code (thanks to Jon Skeet) public class Test { internal Test(string x) { } static void Main() { dynamic d = "...
What's wrong with using super() in a constructor in Java?
When I run static analysis on the following code: public ExtractDBScripts(String resBundleName) { super(); m_mainBundle = ResourceBundle.getBundle(resBundleName); } I get the following error: "JAVA 0058 Constructor 'ExtractDBScripts' calls super()". What is wrong with calling super() from a constructor?...
C# object initialization options
Doesn't object initialization outside of a constructor break encapsulation ? Given: class MyClass { public string _aString; } Shouldn't the _aString member be private and instantiated via a call to the constructor (constructor omitted here): MyClass test = new MyClass("test"); Instead of the alternate method of object in...
Can I create an object from a derived class by constructing the base object with a parameter?
In other words, given a base class shape and a derived class rectangle: class shape { public: enum shapeType {LINE, RECTANGLE}; shape(shapeType type); shape(const shape &shp); } class rectangle : public shape { public: rectangle(); rectangle(const rectangle &rec); } I'd like to know if I could create an instance of rectangl...
question about ColdFusion component constructor name
hi all, i have some questions about constructors in ColdFusion : must i use the name init as the constructor name? if i create an instance of the component without invoking the init method, what is returned? instance=createObject("component","cfcName"); // what value now instance hold can i take the code in the init method out and d...
Prototype Element.update multiple objects
Hi, I'm trying to construct a table with Prototype's New Element function. I was experiencing problems in Firefox when I was updating the thead with the complete content: all th elements plus contents. Firefox was stripping the tags and displays only the contents. Anyways I decided to construct every single th element and then append i...