overriding

问题 Im currently working on a c# project that uses another .net library. This library does (amongst other things) parse a sequence into a tree. All items are of some type that inherits from the abstract class Sequence . I needed to alter the behaviour slightly and subclassed Sequence myself (lets call it MySequence ). After the tree was created, I could replace some tree nodes with objects of my own class. Now, a new version of the library was published, and a Copy function with the following

问题 class GrandParent { public virtual void Foo() { ... } } class Parent : GrandParent { public override void Foo() { base.Foo(); //Do additional work } } class Child : Parent { public override void Foo() { //How to skip Parent.Foo and just get to the GrandParent.Foo base? //Do additional work } } As the code above shows, how can I have the Child.Foo() make a call into GrandParent.Foo() instead of going into Parent.Foo()? base.Foo() takes me to the Parent class first. 回答1: Your design is wrong if

问题 I just can't find any proper piece of code to do what i need. Im using Dict.ContainsKey but due to the fact im always creating the Key i need to look for, i always get false for the ContainsKey (because hashKey is different and im creating the key i want to check all the time). can someone please advise how to override Contains key or how to handle keys comparing in this situation ? My dictionary Looks like Dictionary<someObj, int> public class someObj { public int someobjParam {get;set;}

问题 I'm aware of the Magento best-practices pattern that says that if I want to modify one of Magento's core files, I should copy the file (and matching directory tree structure) from /app/code/core into /app/code/local and modify the copy so that it overrides the original. I need to do that with one of Magento's core XML files - I've modified the file, and I want to make sure that it doesn't get overwritten later when I upgrade Magento. Right now, I have a modified version /app/code/core/Mage

问题 Alright, so here is what I am trying to do. I have a UITextField. When I single tap it, I want to call one of my methods. When I double tap (tap it twice with 1 finger) it, I want to edit the text field (as though I had single tapped it on a normal UITextField.) I am not sure how to go about this. I was thinking of sub-classing UITextField and trying to intercept the touch event as it is sent, but I can't figure out which methods to override to do this. Which methods should I override and how

问题 Should be a newbie question... I have existing code in an existing class, A, that I want to extend in order to override an existing method, A::f(). So now I want to create class B to override f(), since I don't want to just change A::f() because other code depends on it. To do this, I need to change A::f() to a virtual method, I believe. My question is besides allowing a method to be dynamically invoked (to use B's implementation and not A's) are there any other implications to making a

问题 class X { sealed protected virtual void F() { Console.WriteLine("X.F"); } sealed void F1(); protected virtual void F2() { Console.WriteLine("X.F2"); } } In the above code there is compile time error : X.F()' cannot be sealed because it is not an override X.F1()' cannot be sealed because it is not an override Does it mean we can only apply the sealed keyword whey we have to override some methods? 回答1: Well, sealed keyword prevents method from being overriden , and that's why it doesn't make

问题 How do I go about overriding the default functionality when a user clicks the X in a VB.NET form-based application? I am currently handling the MyBase.Closing event... but since it's a DirectX app, I need to do some cleanup before allowing the form the close. 回答1: If you want to do some extra clean up before a form closes, do so in the form's Form Closing event. This event also allows you to cancel the form close through the event's FormClosingEventArgs.Cancel property. The event's

问题 I would like to override console.log and call it on my new function. I try something like this but I get Uncaught TypeError: Illegal invocation : console.log = function() { this.apply(window, arguments); }.bind(console.log); console.log('as'); This is my goal: console.error(exception); should do: console.error = function() { if (typeof exception.stack !== 'undefined') { console.error(exception.stack); } else { console.error.apply(windows, arguments); } }.bind(console.error); console.error('as

问题 I would like to override console.log and call it on my new function. I try something like this but I get Uncaught TypeError: Illegal invocation : console.log = function() { this.apply(window, arguments); }.bind(console.log); console.log('as'); This is my goal: console.error(exception); should do: console.error = function() { if (typeof exception.stack !== 'undefined') { console.error(exception.stack); } else { console.error.apply(windows, arguments); } }.bind(console.error); console.error('as