constructor

Subclass of View constructor not being called

Hi all, I'm subclassing Android's view class, but whenever I make an instance of the view from another class, the constructor never gets called (or so it seems). I've implemented both public myclass (Context context) and public myclass (Context context, AttributeSet, attrs) I can't figure out what I'm doing wrong. Do I need to override...

C++ constructor problem, values not being set

Hi, I'm new to C++ and I'm trying to figure out this problem I'm having with my constructor for one of my classes. What happens is... all my variables are initialized properly except two (health and type). #pragma once #include <irrlicht.h> #include <vector> #include <cassert> using namespace irr; using namespace core; using namespace ...

C++ How to deep copy a struct with unknown datatype?

hi, i have a "data provider" which stores its output in a struct of a certain type, for instance struct DATA_TYPE1{ std::string data_string; }; then this struct has to be casted into a general datatype, i thought about void * or char *, because the "intermediate" object that copies and stores it in its binary tree should be able to...

Passing IDisposable objects through constructor chains

I've got a small hierarchy of objects that in general gets constructed from data in a Stream, but for some particular subclasses, can be synthesized from a simpler argument list. In chaining the constructors from the subclasses, I'm running into an issue with ensuring the disposal of the synthesized stream that the base class constructor...

[C++] Static Class Data Members and Constructors

How do I access a static member in a class with all static methods? I want to have a group of related functions but also have some important data members initialized before any of these functions are called. I thought a class with only static members would be the way to go. Compiler in VS2008 doesn't like me trying to access "a". Sure...

Safe placement new & explicit destructor call

This is an example of my codes: template <typename T> struct MyStruct { T object; } template <typename T> class MyClass { MyStruct<T>* structPool; size_t structCount; MyClass(size_t count) { this->structCount = count; this->structPool = new MyStruct<T>[count]; for( size_t i=0 ; i<count ; i++ ) ...

Creating instance in java class

Please advise me the difference between two ways of declaration of java constructor public class A{ private static A instance = new A(); public static A getInstance() { return instance; } public static void main(String[] args) { A a= A.getInstance(); } } AND public class B{ public B()...

Loading data in constructors and not in constructors

I just want to know the difference between loading the data inside the constructor and loading the data outside the constructor but not inside any methods example: Loading inside constructor public class Model{ Object testobject; public Model(){ testobject=new Object(); } } VS example: Loading outside constructor ...

Java Constructor Style (Check parameters aren't null)

What are the best practices if you have a class which accepts some parameters but none of them are allowed to be null? The following is obvious but the exception is a little unspecific: public class SomeClass { public SomeClass(Object one, Object two) { if (one == null || two == null) { throw new I...

Throwing Exception in CTOR and Smart Pointers

Is it OK to have the following code in my constructor to load an XML document into a member variable - throwing to caller if there are any problems: MSXML2::IXMLDOMDocumentPtr m_docPtr; //member Configuration() { try { HRESULT hr = m_docPtr.CreateInstance(__uuidof(MSXML2::DOMDocument40)); ...

get and set for class in model - MVC 2 asp.net

Hi there, I want to improve the program so it has a proper constructor but also works with the models environment of MVC. I currently have: public void recordDocument(int order_id, string filename, string physical_path, string slug, int bytes) { ArchiveDocument doc = new ArchiveDocument(); doc.order_id...

F# constructor syntax - overiding and augmenting new

I have a non-disposable class with Open/Close syntax that I'd like to be able to use, so I'm trying to inherit from it, and work the Open into the new and the Close into Dispose. The second part is ok, but I can't work out how to do the Open: type DisposableOpenCloseClass(openargs) = inherit OpenCloseClass() //do this.Open(open...

c++/boost: use tuple ctors when subclassing

Hi there, is there some way to use a boost tuple's ctors as an addition to the subclass methods (and ctors) like here? // typedef boost::tuple<int, SomeId, SomeStatus> Conn; // Conn(1); // works and initializes using default ctors of Some* struct Conn : boost::tuple<int, AsynchId, AccDevRetStatus> {}; Conn(1); // "no matching function ...

VB.Net calling New without assigning value

In C# I can do this: new SomeObjectType("abc", 10); In other words, I can call new without assigning the created instance to any variable. However, in VB.Net it seems I cannot do the same thing. New SomeObjectType("abc", 10) ' syntax error Is there a way to do this in VB.Net? ...

How to create a Binary Tree from a General Tree?

I have to solve the following constructor for a BinaryTree class in java: BinaryTree(GeneralTree<T> aTree) This method should create a BinaryTree (bt) from a General Tree (gt) as follows: Every Vertex from gt will be represented as a leaf in bt. If gt is a leaf, then bt will be a leaf with the same value as gt If gt is not a leaf...

Using new to allocate an array of class elements with an overloaded constructor in C++.

As an example say I have a class foo that does not have a default constructor but one that looks like this foo:foo(int _varA,int _varB) { m_VarA = _varA; m_VarB = _varB; } How would I allocate an array of these. I seem to remember trying somthing like this unsuccessfully. foo* MyArray = new foo[100](25,14). I don't think thi...

Constructor Overload Problem in C++ Inheritance

Here my code snippet: class Request { public: Request(void); ……….. } Request::Request(void) { qDebug()<<"Request: "<<"Hello World"; } class LoginRequest :public Request { public: LoginRequest(void); LoginRequest(QDomDocument); …………… } LoginRequest::LoginRequest(void) { qDebug()<<"LoginRequest: "<<"Hello World"; requestType=LOG...

How can I create two contructors that act differently but recieve the same data type?

public class Parser { Downloader download = new Downloader(); HtmlDocument Page; public Parser(string MovieTitle) { Page = download.FindMovie(MovieTitle); } public Parser(string ActorName) { Page = download.FindActor(ActorName); } } I want to create a constructor that will allow other d...

How can i create array of my class with default constructor ?

Hello For example MYCLASS[] myclass = new MYCLASS[10]; Now myclass array is all null array but i want to have default constructed Array .I know that i can write loops for set default constructed but i am looking for more easy and simple way. ...

How to use reflection to get a default constructor?

I am writing a library that generates derived classes of abstract classes dynamically at runtime. The constructor of the derived class needs a MethodInfo of the base class constructor so that it can invoke it. However, for some reason Type.GetConstructor() returns null. For example: abstract class Test { public abstract void F(); } ...