This question is pretty old, and I don’t know if it would have worked with the version of WPF back in 2010, but now you can make it work by using the “real” (internal) name of the nested type: <local:A+B /> If you’ve ever looked a disassembled code, that’s how nested types look like: ParentTypeName+Nested
Local variables always live on the stack, the moment method is over all local variables are gone. But your inner class objects might be on heap even after the method is over (Say an instance variable holds on to the reference), so in that case it cannot access your local variables since they are gone, … Read more
It’s called a “qualified superclass constructor invocation”. Citing from here: Explicit constructor invocation statements can be divided into two kinds: Alternate constructor invocations begin with the keyword this (possibly prefaced with explicit type arguments). They are used to invoke an alternate constructor of the same class. Superclass constructor invocations begin with either the keyword super … Read more
A non-static nested class in Java contains an implicit reference to an instance of the parent class. Thus to instantiate a Node, you would need to also have an instance of Stack. In a static context (the main method), there is no instance of Stack to refer to. Thus the compiler indicates it can not … Read more
Create the BroadcastReceiver dynamically: In your BroadcastReceiver class define class member: YourMainActivity yourMain = null; and method: setMainActivityHandler(YourMainActivity main){ yourMain = main; } from your MainActivity do: private YourBroadcastReceiverClassName yourBR = null; yourBR = new YourBroadcastReceiverClassName(); yourBR.setMainActivityHandler(this); IntentFilter callInterceptorIntentFilter = new IntentFilter(“android.intent.action.ANY_ACTION”); registerReceiver(yourBR, callInterceptorIntentFilter); finally, when yourBR.onReceive is fired you can call: yourMain.methodOfMainActivity();
Once the anonymous class instance has been implicitly cast into the named type it can’t be cast back because there is no name for the anonymous type. You can access the additional members of the anonymous inner class through this within the class, in the expression immediate after the expression and the type can be … Read more
Yes, you can instantiate a private inner class with Java reflection. To do that, you need to have an instance of outer class and invoke the inner class constructor which will use outer class instance in its first argument. class OuterClass { private class InnerClass { { //this block is just to confirm that the … Read more
… because the system would have to instantiate a large Activity object to just have instanitated a recevier instance? Yup, just like any other non-static inner class. It has to get an instance of the outer class from somewhere (e.g. by instantiating or by some other mechanism) before it can create an instances of the … Read more
(Edit: expanded on the answer to answer some of the comments) The compiler takes the inner classes and turns them into top-level classes. Since private methods are only available to the inner class the compiler has to add new “synthetic” methods that have package level access so that the top-level classes have access to it. … Read more
Nested classes (probably best to avoid the word “inner” as nested classes in C# are somewhat different to inner classes in Java) can indeed be very useful. One pattern which hasn’t been mentioned is the “better enum” pattern – which can be even more flexible than the one in Java: public abstract class MyCleverEnum { … Read more