overriding

问题 How to override the TextProperty Metadata to set the UpdateSourceTrigger.PropertyChanged by default while using the functionality from the base TextBox Class TextBox.OnTextPropertyChanged TextBox.CoerceText methods, when both mentioned are private ? public class MyTextBox : System.Windows.Controls.TextBox { static MyTextBox() { TextProperty.OverrideMetadata(typeof(TextBox), new FrameworkPropertyMetadata( string.Empty, FrameworkPropertyMetadataOptions.Journal | FrameworkPropertyMetadataOptions

问题 I'm trying to override in the local folder a module which is in the local folder also, but I don't know if it's possible. This is what I've done. I've created /local/Mycompany/Modulename/Model/Model.php which i'd like to override the /local/Othercompany/Modulename/Model/Model.php my model.php is: class Mycompany_Modulename_Model_Model extends Othercompany_Modulename_Model_Model { ... } and my config.xml <global> <models> <othercompanymodulename> <rewrite> <model>Mycompany_Modulename_Model

问题 abstract public class car { abstract void drive(); } As in the code snippet above, what exactly is the purpose of an abstract method in Java? From what I can gather, by definition, they aren't allowed to have bodies. 回答1: When you make things implement the same abstract class, you are saying, these things are alike at a high level, but they vary in the particulars of how they do things. An abstract method is how you say, "Here's something that all the things that extend this class have to do,

问题 abstract public class car { abstract void drive(); } As in the code snippet above, what exactly is the purpose of an abstract method in Java? From what I can gather, by definition, they aren't allowed to have bodies. 回答1: When you make things implement the same abstract class, you are saying, these things are alike at a high level, but they vary in the particulars of how they do things. An abstract method is how you say, "Here's something that all the things that extend this class have to do,

问题 Refer to this question: Hide virtual function with non-virtual override And this question: override on non-virtual functions A function that overrides a virtual function is virtual too, even though it's not explicitly declared virtual. My technical question is: Is there away to make that overriding function non-virtual (and applies that to classes lower in the hierarchy)? In other words, can I turn the "virtuality" off? Obviously we can override a non-virtual function with a virtual function.

问题 I have a method, in a class called "PlaceParser" that extends "ModelParser": protected Place parseModel(JSONObject element) ... A Place is a sub class of Model. Should the @Override annotation be added to the above code? As the method has a different return type, does this still count as overriding the base class method with the same name and arguments / does the return type alter the 'signature'? The "ModelParser" method looks like this "ModelT" also extends "Model": protected abstract

问题 Does a command exist, like \deprecated , but to mark overridden functions? Java has an annotation @override for functions you have overridden. I would like to do the same in C++, so that I can to see the superclass functions I've overridden. At best, the documentation page should also show all class member functions, which are inherited, but not explicitly overridden with hyper-links to the superclass functions. I know there is a way to copy the documentation from the superclass method. But I

问题 I know that main() can be overloaded in a class with the compiler always taking the one with String[] args as arguments as the main method from where the execution starts. But is it possible to declare the same main(String args[]) in an interface and implement it in different classes differently? For example, package test; interface test { public void main(String args[]); public void display(); } package test; class Testclass1 implements test { public void display() { System.out.println(

问题 I Knew there are plenty of articles/questions in stackoverflow describing about upcasting and downcasting in Java. And I knew what is upcasting and downcasting. But my question is not specfic to that. Upcasting - Conversion from child to parent - Compiler takes care. No cast is required Downcasting - Conversion from parent to child - Explicit cast is required public class Animal { public void getAnimalName(){ System.out.println("Parent Animal"); } } public class Dog extends Animal{ public

问题 Let's suppose we have a base class which has a virtual method: class BaseClass { virtual void MethodToOverride() const { DoSomething(); } }; And a derived class which overrides the method (depending on the situation we can make it again virtual or not): class DerivedClass : public BaseClass { void MethodToOverride() const { DoSomethingElse(); } } If we make a mistake, for example defining the MethodToOverride non const or with a wrong character, we simply define a new method, for example: