Create an instance of an object from a String in D

问题:

How would I do the Dart equivalent of this Java code?

Class<?> c = Class.forName("mypackage.MyClass");
Constructor<?> cons = c.getConstructor(String.class);
Object object = cons.newInstance("MyAttributeValue");

(From Jeff Gardner)

回答1:

The Dart code:

ClassMirror c = reflectClass(MyClass);
InstanceMirror im = c.newInstance(const Symbol(''), ['MyAttributeValue']);
var o = im.reflectee;

Learn more from this doc: http://www.dartlang.org/articles/reflection-with-mirrors/

(From Gilad Bracha)

回答2:

Using built_mirrors you can do it next way:

library my_lib;

import 'package:built_mirrors/built_mirrors.dart';

part 'my_lib.g.dart';

@reflectable
class MyClass {

  String myAttribute;

  MyClass(this.myAttribute);
}

main() {
  _initMirrors();

  ClassMirror cm = reflectType(MyClass);

  var o = cm.constructors[''](['MyAttributeValue']);

  print("o.myAttribute: ${o.myattribute}");
}