HttpRequest 构造函数

HttpRequest()

适用于任何类型的请求（GET、POST等）的通用构造函数。

此调用与open一起使用

var request = new HttpRequest();
request.open('GET', 'http://dartlang.org');
request.onLoad.listen((event) => print(
    'Request complete ${event.target.reponseText}'));
request.send();

是（更详细的）等价于

HttpRequest.getString('http://dartlang.org').then(
    (result) => print('Request complete: $result'));

实现

factory HttpRequest() {
  return HttpRequest._create_1();
}