overriding

问题 Why does this produce an error in Flash Builder?: package { public class Foo { override public function toString():String { return "Foo"; } } } Tab completion suggests that this is available for override... Error message: Multiple markers at this line: -public -1020: Method marked override must override another method. -overridesObject.toString 回答1: Remove override on the toString() method. There is a popular misconception among about the toString() method, namely: if one wants to provide a

问题 Answering this question: How to GUI - Using paintcomponent() to initialize a GUI and then to add GUI based on mouse I've stated this: You don't override paintComponent() properly. This is a protected method, not public. If you add @Override annotation on this method then the compiler will complain. But @peeskillet wisely pointed out this: The compiler will not complain about public or protected with paintComponent . You can override with a higher visibility but not a lower one. public is

问题 According to the documentation of SafeVarargs, the @SafeVarargs annotation can be applied only to constructors or variable arity methods that are either static or final . This is, I have read, to eliminate issues with annotation inheritance; that is to say, annotations on methods are only allowed if the method cannot be overridden. Clearly, constructors, static methods, and final methods cannot be overridden. However, neither can private methods or methods in a final class . Someone has

问题 This question already has answers here : Function with same name but different signature in derived class (2 answers) Closed 2 years ago . I need to understand why C++ don't allow to access Grandparent overloaded functions in Child if any of the overloaded function is declared in Parent. Consider the following example: class grandparent{ public: void foo(); void foo(int); void test(); }; class parent : public grandparent{ public: void foo(); }; class child : public parent{ public: child(){ /

问题 How bad is it to redefine a class method from another, third-party module, in Python? In fact, users can create NumPy matrices that contain numbers with uncertainty; ideally, I would like their code to run unmodified (compared to when the code manipulates float matrices); in particular, it would be great if the inverse of matrix m could still be obtained with m.I , despite the fact that m.I has to be calculated with my own code (the original I method does not work, in general). How bad is it

问题 I have an Entity Data Model that I have created, and its pulling in records from a SQLite DB. One of the Tables is People, I want to override the person.Equals() method but I'm unsure where to go to make such a change since the Person object is auto-generated and I don't even see where that autogen code resides. I know how to override Equals on a hand made object, its just where to do that on an autogen one. 回答1: You need to create a partial class. Add a new .cs file to your solution, and

问题 Is there anyway to override internal framework method when subclassing in Swift? Ex. Superclass public class BarChartRenderer: ChartDataRendererBase { internal func drawDataSet(context context: CGContext, dataSet: BarChartDataSet, index: Int) { ... } } and I want to override this method to draw differently that dataSet (iOS-Charts) public class ESBarChartRenderer: BarChartRenderer { overide func drawDataSet(context context: CGContext, dataSet: BarChartDataSet, index: Int) { ... } } but when I

问题 I am trying to make text inside a transparent div have no opacity, aka be completely black: <div style="opacity:0.6;background:#3cc;"> <p style="background:#000;opacity:1">This text should be all black</p> </div> Is this possible to do with only CSS? Thanks in advance 回答1: The easiest way is to style the background of the parent div with opacity/alpha: div { background: #fff; /* for browsers that don't understand the following rgba rule */ background-color: rgba(255,255,255,0.5); /* rgb,

问题 There's something I want to customize in the System.Web.Script.Services.ScriptHandlerFactory and other .NET stuff inside an internal class. Unfortunately, it's an internal class. What options do I have when trying to customize a method in this class? 回答1: You might find this recent article enlightening. Basically, it says that you can't override anything marked internal , and the source is about as authoritative as it gets. Best you can hope for is an extension method. 回答2: The internal

问题 A Superclass : class MySuperView : UIView{ var aProperty ; } A subclass inheritance the super class : class Subclass : MySuperClass{ // I want to override the aProperty's setter/getter method } I want to override the superclass's property's setter/getter method , how to override this method in Swift ? Please help me , thanks . 回答1: What do you want to do with your custom setter? If you want the class to do something before/after the value is set, you can use willSet / didSet : class