methods

问题 In some Java methods I see that an Interface argument is required. Since an Interface cannot be instantiated, does that mean that an object of every class that implements this interface can be passed as argument? For example in the setOnClickListener method of the ListView class in Android, setOnItemClickListener(AdapterView.OnItemClickListener listener) the OnItemClickListener interface (nested in the AdapterView abstract class) is needed as an argument. What kind of object is required to be

问题 Once I've executed window.stop() , how can I resume default actions? I need to make toggle/switch function, that once fired will run window.stop() , and with second run will recover window actions disabled by window.stop() . 回答1: I misunderstood before how window.stop() works. I was wrong, there are no any "direct inbuilt" javascript method to reload ONLY THESE ELEMENTS stopped by window.stop(), so by this meaning it's impossible. However, if it's needed, we can: loop through each element on

问题 Once I've executed window.stop() , how can I resume default actions? I need to make toggle/switch function, that once fired will run window.stop() , and with second run will recover window actions disabled by window.stop() . 回答1: I misunderstood before how window.stop() works. I was wrong, there are no any "direct inbuilt" javascript method to reload ONLY THESE ELEMENTS stopped by window.stop(), so by this meaning it's impossible. However, if it's needed, we can: loop through each element on

问题 Let's say we have a base class: public abstract class BaseFragment extends Fragment { ... protected abstract boolean postExec(); ... } And then derive from it to have other class(es) (e.g. Fragment_Movie, Fragment_Weather ...) public class Fragment_Music extends BaseFragment{ @Override protected boolean postExec() { return false; } } However, when adding a new method to the base class: public abstract class BaseFragment extends Fragment { ... protected abstract boolean postExec(); protected

问题 I am trying to pass a selected "get"-method of class A to a method in class B. I have checked out Java Pass Method as Parameter, but I was not able to adopt the interface approach to my problem in a reasonable way. I would prefer to not use java 8 (lambdas) and if possible avoid reflection as well. My feeling is, that I am looking at my problem the wrong way. Here is the specific simplified example of what I am trying to accomplish: I have a class containing some fields and get-methods:

问题 I've found several responses to this, but none pertaining to PHP (which is an extremely weak typed language): With regards to PHP , is it appropriate to return false, null, or an empty array in a method that would usually return an array, but has a failure occur? In other words, if another developer jumped in on my project, what would they expect to see? 回答1: An array is a collection of things. An empty array would signal that "everything went fine, there just isn't anything in that

问题 I've found several responses to this, but none pertaining to PHP (which is an extremely weak typed language): With regards to PHP , is it appropriate to return false, null, or an empty array in a method that would usually return an array, but has a failure occur? In other words, if another developer jumped in on my project, what would they expect to see? 回答1: An array is a collection of things. An empty array would signal that "everything went fine, there just isn't anything in that

问题 I want to be notified when certain things happen in some of my classes. I want to set this up in such a way that the implementation of my methods in those classes doesn't change. I was thinking I'd have something like the following module: module Notifications extend ActiveSupport::Concern module ClassMethods def notify_when(method) puts "the #{method} method was called!" # additional suitable notification code # now, run the method indicated by the `method` argument end end end Then I can

问题 I want to be notified when certain things happen in some of my classes. I want to set this up in such a way that the implementation of my methods in those classes doesn't change. I was thinking I'd have something like the following module: module Notifications extend ActiveSupport::Concern module ClassMethods def notify_when(method) puts "the #{method} method was called!" # additional suitable notification code # now, run the method indicated by the `method` argument end end end Then I can

问题 I am new to Java and am trying to access method variables outside of the method, but it doesn't work. Code is below: public class MethodAccess { public static void minus() { int a=10; int b=15; } public static void main(String[] args) { //Here i want to access variable names a & b that is in minus() int c = b - a; } } 回答1: Because a and b are local variables. If you want to access to them in your main method, you need to modify your code. For example : public class methodacess { private