implementation

I'm asking specifically about VB.NET, but I imagine the general principles are the same in other languages. I thought an event was a first-class concept in .NET, but it seems from reflection that its just a specific method which is called when the event is raised. How do AddHandler and RemoveHandler modify the method dynamically (AFAIK, events pre-date DynamicMethod s? How does RaiseEvent call the method? Why are AddHandler , RemoveHandler , and RaiseEvent implemented as statements instead of methods ? No, an event is just a combination of two or three methods (the "raise" part is optional) in

Due to the benchmarking done in other threads (cf. https://stackoverflow.com/a/397617/1408611 ) it was shown that instanceof in Java 6 is actually quite fast. How is this achieved? I know that for single inheritance, the fastest idea is having some nested interval encoding where each class maintains a [low,high] interval and an instanceof is simply an interval inclusion test, i.e. 2 integer comparisons. But how is it made for interfaces (as interval inclusion only works for single inheritance)? And how is class loading handled? Loading new subclasses means that a lot of intervals have to be

I created a class which implements IDisposable interface and VisualStudio IDE brought the Dispose method for me. I am wondering what code i should write inside the Dispose method so that it will take care of my memory management or whatever stuff it should do. public class ESNVerification : IDisposable { public bool Save(string a,string b) { //Save the data to table return true; } public void Dispose() { throw new NotImplementedException(); // Really what i should do here ? } } I recommend Three Simple Rules for how to implement IDisposable; simplified here: Rule 1: Don't do it (unless you

Can I implement OnClickListener and SurfaceHolder like this : public class MainActivity extends Activity implements SurfaceHolder.Callback,OnClickListener Yes, in Java a class can implement many different interfaces. This compensates the lack of multiple inheritance in Java, as opposed to e.g. C++ where multiple inheritance is allowed. 来源： https://stackoverflow.com/questions/17507225/can-an-activity-have-two-implements

I'd like to convert a char to lower case in a J2ME app. The usual Character.toLowerCase() doesn't work for an arbitrary Unicode character in J2ME, so I need some light API, or, preferably, a piece of code that would do so. Thanks! Based on the toLowerCase() method from Character in JavaSE JDK: char lowerChar = (char)CharacterData.of((int)upperChar).toLowerCase((int)upperChar); You can read the source code from the JDK and understand what is really done here and apply the same thing with your own classes in JME. Resources : grepcode - Character.toLowerCase() char toLowerCase(char c){ if(c>=97 &

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 method virtual? Am I breaking some kind of good programming practice? Will this affect any other code trying

I have Activity with Handler (UI thread) I start new Thread and make handler.post(new MyRunnable()) - (new work thread) Android documentation said about post method: "Causes the Runnable r to be added to the message queue. The runnable will be run on the thread to which this handler is attached." Handler attached to UI thread. How android can run runnable in the same UI thread without new thread creation? Is new thread will be created using Runnable from handler.post()? Or it's only run() method will be called from Runnable subclass? Handler attached to UI thread. Correct. How android can run