Search Results

Search found 14034 results on 562 pages for 'interface inheritance'.

Page 92/562 | < Previous Page | 88 89 90 91 92 93 94 95 96 97 98 99  | Next Page >

  • inheritence in c#

    - by scatman
    i am trying to create a custom (TreeView) control by inheriting from (RadTreeView) control by doing so: public class CustTreeView : RadTreeView but not all methods where inherited!!. for example: i can do: RadTreeView r = new RadTreeView(); r.LoadContentFile("Sample.xml"); but not: CustTreeView r = new CustTreeView (); r.LoadContentFile("Sample.xml"); so LoadContentFile is a method in RadTreeView but not in CustTreeView!!any explanation?

    Read the article

  • When calling a static method on parent class, can the parent class deduce the type on the child (C#)

    - by Matt
    Suppose we have 2 classes, Child, and the class from which it inherits, Parent. class Parent { public static void MyFunction(){} } class Child : Parent { } Is it possible to determine in the parent class how the method was called? Because we can call it two ways: Parent.MyFunction(); Child.MyFunction(); My current approach was trying to use: MethodInfo.GetCurrentMethod().ReflectedType; // and MethodInfo.GetCurrentMethod().DeclaringType; But both appear to return the Parent type. If you are wondering what, exactly I am trying to accomplish (and why I am violating the basic OOP rule that the parent shouldn't have to know anything about the child), the short of it is this (let me know if you want the long version): I have a Model structure representing some of our data that persists to the database. All of these models inherit from an abstract Parent. This parent implements a couple of events, such as SaveEvent, DeleteEvent, etc. We want to be able to subscribe to events specific to the type. So, even though the event is in the parent, I want to be able to do: Child.SaveEvent += new EventHandler((sender, args) => {}); I have everything in place, where the event is actually backed by a dictionary of event handlers, hashed by type. The last thing I need to get working is correctly detecting the Child type, when doing Child.SaveEvent. I know I can implement the event in each child class (even forcing it through use of abstract), but it would be nice to keep it all in the parent, which is the class actually firing the events (since it implements the common save/delete/change functionality).

    Read the article

  • using "Reference3 Interface" to add desired references to a project

    - by BDotA
    I found this: http://msdn.microsoft.com/en-us/library/vslangproj80.reference3%28VS.80%29.aspx what I have in mind is that many of the references that we add to our project are on a network drive and there are TON of them. Adding references to the project by right clicking on the References in the porject and choosing add reference is a pain. so I was wondering if I can take advantage of something like what I posted the link to it and have a small program,add-in,macro, etc! that we can give it a list of the references that I want and it will add them to the project.

    Read the article

  • PHP inheriting/extending a particular instance of an Object

    - by delta9
    Is there any way to force PHP to extend an existing/particular (and for that matter, already instantiated) instance of an object? This imaginary code should explain what I am wondering: class Base { public $var; function __construct($var){ $this->var = $name; } } class Extender extends Base { function __construct($parent) { parent = $parent; } } $base = new Base('yay!'); $extender = new Extender($base); echo 'Extended base var value: '.$extender->var.'<br/>'; Output (would be): Extended base var value: yay! To be clear, I am wanting to instantiate an object that extends a PARTICULAR INSTANCE of another object, one that has already been instantiated. I am aware that I can pass a reference to an object to another object (via it's constructor function) and then add it as a property of the receiving object, I'm wondering if there is a real way to do this?

    Read the article

  • Force calling the derived class implementation within a generic function in C#?

    - by Adam Hardy
    Ok so I'm currently working with a set of classes that I don't have control over in some pretty generic functions using these objects. Instead of writing literally tens of functions that essentially do the same thing for each class I decided to use a generic function instead. Now the classes I'm dealing with are a little weird in that the derived classes share many of the same properties but the base class that they are derived from doesn't. One such property example is .Parent which exists on a huge number of derived classes but not on the base class and it is this property that I need to use. For ease of understanding I've created a small example as follows: class StandardBaseClass {} // These are simulating the SMO objects class StandardDerivedClass : StandardBaseClass { public object Parent { get; set; } } static class Extensions { public static object GetParent(this StandardDerivedClass sdc) { return sdc.Parent; } public static object GetParent(this StandardBaseClass sbc) { throw new NotImplementedException("StandardBaseClass does not contain a property Parent"); } // This is the Generic function I'm trying to write and need the Parent property. public static void DoSomething<T>(T foo) where T : StandardBaseClass { object Parent = ((T)foo).GetParent(); } } In the above example calling DoSomething() will throw the NotImplemented Exception in the base class's implementation of GetParent(), even though I'm forcing the cast to T which is a StandardDerivedClass. This is contrary to other casting behaviour where by downcasting will force the use of the base class's implementation. I see this behaviour as a bug. Has anyone else out there encountered this?

    Read the article

  • C++ enforce conditions on inherited classes

    - by user231536
    I would like to define an abstract base class X and enforce the following: a) every concrete class Y that inherits from X define a constructor Y(int x) b) it should be possible to test whether two Y objects are equal. For a, one not very good solution is to put a pure virtual fromInt method in X which concrete class will have to define. But I cannot enforce construction. For b), I cannot seem to use a pure virtual method in X bool operator == (const X& other) const =0; because in overridden classes this remains undefined. It is not enough to define bool operator == (const Y& other) const { //stuff} because the types don't match. How do I solve these problems?

    Read the article

  • C# Why does code compile fine when there is an ambiguous virtual method?

    - by Jimbo
    I have a class (Class B) that inherits another class (Class A) that contains virtual methods. Mistakenly, I omitted the override keyword when declaring a (supposed to be) overriding method in Class B. Class A public class ClassA{ public virtual void TestMethod(){ } } Class B public class ClassB : ClassA{ public void TestMethod(){ } } The code compiled without a problem. Can anyone explain why?

    Read the article

  • Are static members inherited? (C++)

    - by Keand64
    When static members are inherited, are they static for the entire heirarchy, or just that class, ie: class SomeClass { public: SomeClass(){total++;} static int total; }; class SomeDerivedClass: public SomeClass { public: SomeDerivedClass(){total++;} }; int main() { SomeClass A; SomeClass B; SomeDerivedClass C; return 0; } would total be 3 in all three instances, or would it be 2 for SomeClass and 1 for SomeDerivedClass?

    Read the article

  • Query interface for iPhone CoreData store

    - by JT
    Hi, another iPhone newbie question... I have the following: NSPersistentStoreCoordinator NSManagedObjectContext NSManagedObjectModel Is it possible to run queries directly on the store (since its a sqlite DB)? I'm trying to delete all the records from a tableview, and figured a "DELETE FROM table" would be nice and quick as opposed to looping through the records and removing them manually (which i'm also struggling with). Thanks for your time, James

    Read the article

  • Determine an object's class returned by a factory method (Error: function does not take 1 arguments

    - by tzippy
    I have a factorymethod that either returns an object of baseclass or one that is of derivedclass (a derived class of baseclass). The derived class has a method virtual void foo(int x) that takes one argument. baseclass however has virtual void foo() without an argument. In my code, a factory method returns a pointer of type bar that definetly points to an object of class derivedclass. However since this is only known at runtime I get a compiler error saying that foo() does not take an argument. Can I cast this pointer to a pointer of type derivedclass? std::auto_ptr<baseclass> bar = classfactory::CreateBar(); //returns object of class derivedclass bar->foo(5); class baseclass { public: virtual void foo(); } class derivedclass : public baseclass { public: virtual void foo(int x); }

    Read the article

  • WPF inherited UserControl lost VS designer support

    - by PaN1C_Showt1Me
    Hi ! I' written this UserControl: <my:MyUserControl x:Class="MyClass" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:my="clr-namespace:MyNameSpace.MyControls;assembly=MyAssembly"> </my:MyUserControl> public partial class Editor : MyNameSpace.MyControls.MyUserControl {} Everything works, the control is shown in the VS 2008 Designer, but I cannot click directly in the elements and select them as it was with UserControl. Any idea how to solve it?

    Read the article

  • Button not moving on my interface

    - by user1500134
    First before I say anything I want to announce that i'm fairly new to this kind of stuff so don't get all super techie on me :D ! Ok so i'm making an app and i'm trying to get a button to move to certain coordinates depending on the screen size of the phone (4, 4S, 5, etc...). I have correct syntax but the button will not move at all. Here is the part of my .m ViewController file... - (void)viewDidLoad { if([[UIScreen mainScreen] respondsToSelector:NSSelectorFromString(@"scale")]) { if ([[UIScreen mainScreen] scale] < 1.1) { CGRect frame = done.frame; frame.origin.x = 129; //New x coordinate frame.origin.y = 401; //New y coordinate done.frame = frame; NSLog(@"Standard Resolution"); } if ([[UIScreen mainScreen] scale] > 1.9) { NSLog(@"High Defenition Resolution"); } } [super viewDidLoad]; // Do any additional setup after loading the view from its nib. } The NSLog is triggering int he console saying 'Standard Resolution'but the button doesn't move from where I placed it in the XIB file. This may be a small stupid mistake but hopefully you can help me anyways... Thanks guys! :) P.S. Yes I did link my IBOutlet to the button

    Read the article

  • Create object of unknown class (two inherited classes)

    - by Paul
    I've got the following classes: class A { void commonFunction() = 0; } class Aa: public A { //Some stuff... } class Ab: public A { //Some stuff... } Depending on user input I want to create an object of either Aa or Ab. My imidiate thought was this: A object; if (/*Test*/) { Aa object; } else { Ab object; } But the compiler gives me: error: cannot declare variable ‘object’ to be of abstract type ‘A’ because the following virtual functions are pure within ‘A’: //The functions... Is there a good way to solve this?

    Read the article

  • Class or interface expected error (java)

    - by David
    When i try to compile this: public static int compareCardhl (Card c1, Card c2) } if (c1.suit > c2.suit) return 1 ; if (c1.suit < c2.suit) return -1 ; if (c1.rank > c2.rank) return 1 ; if (c1.rank < c2.rank) return -1 ; return 0; } i get a lot of class or intereface expected errors. They all point at the if's. i also get a ; expected error at the end of Card c2). whats going wrong here?

    Read the article

  • Can I make a derived class inherit a derived member from its base class in Java?

    - by Eric
    I have code that looks like this: public class A { public void doStuff() { System.out.print("Stuff successfully done"); } } public class B extends A { public void doStuff() { System.out.print("Stuff successfully done, but in a different way"); } public void doMoreStuff() { System.out.print("More advanced stuff successully done"); } } public class AWrapper { public A member; public AWrapper(A member) { this.member = member; } public void doStuffWithMember() { a.doStuff(); } } public class BWrapper extends AWrapper { public B member; public BWrapper(B member) { super(member); //Pointer to member stored in two places: this.member = member; //Not great if one changes, but the other does not } public void doStuffWithMember() { member.doMoreStuff(); } } However, there is a problem with this code. I'm storing a reference to the member in two places, but if one changes and the other does not, there could be trouble. I know that in Java, an inherited method can narrow down its return type (and perhaps arguments, but I'm not certain) to a derived class. Is the same true of fields?

    Read the article

  • Problem with inherited classes in C#

    - by Unniloct
    I have a class called "Entity," with two child classes: "Creature" and "Item." (I'm making a game.) Creature has two functions called "Attack," one for attacking Creatures, and one for attacking Items. So far, everything works well. Now I'm working on the shooting bit, so I have a function called SelectTarget(). It takes all of the Entities (both Creatures and Items) in the player's view that the player can shoot and lets the player choose one. So here lies the problem: SelectTarget() returns an Entity, but I need some code to figure out whether that Entity is a Creature or an Item, and process it appropriately. Since this question looks kind of empty without any code, and I'm not 100% sure my explanation is good enough, here's where I'm at: if (Input.Check(Key.Fire)) { Entity target = Game.State.SelectTarget.Run(); this.Draw(); if (target != null) { //Player.Attack(target); // This won't work, because I have: // Player.Attack((Creature)Target) // Player.Attack((Item)Target) // but nothing for Entity, the parent class to Creature and Item. return true; } } (If the way the game is laid out seems weird, it's a roguelike.)

    Read the article

  • unable to pas derived List<>

    - by Tarscher
    Hi all, I have class A {} class B : A {} I also have a method that expects a List parameter void AMethod(List<A> parameter) {} Why can't I List<B> bs = new List<B>(); AMethod(bs); And secondly what is the most elegant way to make this work? regards

    Read the article

  • Root base class in C++

    - by Littlesmith
    Every object in .NET inherits (directly or indirectly) from the common root base "Object". Is there such a common object root in C++? How do I pass any object to a function? public void DoSomeStuff(object o) { ... }

    Read the article

  • question about interface

    - by davit-datuashvili
    i have posted this question http://stackoverflow.com/questions/2874487/how-can-i-implement-this-python-snippet-in-java i have compiled it now i need to use in main project public static void main(String[]args){ } ? can anybody show me example?

    Read the article

  • question about interface

    - by davit-datuashvili
    i have posted this question http://stackoverflow.com/questions/2874487/how-can-i-implement-this-python-snippet-in-java i have compiled it now i need to use in main project public static void main(String[]args){ } ? can anybody show me example?

    Read the article

  • question about interface

    - by davit-datuashvili
    i have posted this question http://stackoverflow.com/questions/2874487/how-can-i-implement-this-python-snippet-in-java i have compiled it now i need to use in main project public static void main(String[]args){ } ? can anybody show me example?

    Read the article

  • PHP class extends not working why and is this how to correctly extend a class?

    - by Matthew
    Hi so I'm trying to understand how inherteince works in PHP using object oriented programming. The main class is Computer, the class that is inheriting is Mouse. I'm extedning the Computer class with the mouse class. I use __construct in each class, when I istinate the class I use the pc type first and if it has mouse after. For some reason computer returns null? why is this? class Computer { protected $type = 'null'; public function __construct($type) { $this->type = $type; } public function computertype() { $this->type = strtoupper($this->type); return $this->type; } } class Mouse extends Computer { protected $hasmouse = 'null'; public function __construct($hasmouse){ $this->hasmouse = $hasmouse; } public function computermouse() { if($this->hasmouse == 'Y') { return 'This Computer has a mouse'; } } } $pc = new Computer('PC', 'Y'); echo $pc->computertype; echo $pc->computermouse;

    Read the article

  • Hibernate subclass with foreign key relationships

    - by shikarishambu
    I need some help defining the following object hierarchy/ database relationship in Hibernate From the object sense – Agent is inherited from Person and Agency is inherited from Organization. they are inherited from Party which can have multiple Addresses associated with it The database consists of Agent - ID - Name -PartyID (references Party.ID) Agency -ID -Name -PartyID (references Party.ID) Address -AddrID -PartyID (references Party.ID) -Street Party. -PartyID

    Read the article

< Previous Page | 88 89 90 91 92 93 94 95 96 97 98 99  | Next Page >