Cannot load Dart script dart:io
Failed to load resource

如果我注释掉#import(‘dart：io’);我错了,我得到一个编译错误,但它启动,直到我按下按钮,我是否收到运行时错误：

Internal error: ‘http://127.0.0.1:3030/home/david/dart/samples/htmlIO/htmlIO.dart’: Error: line 13 pos 26: type ‘HttpClient’ is not loaded
var connection = new HttpClient().get(‘www.google.com’,80,‘/’);

……这是预期的.

所以我的问题是：如何导入dart：html&飞镖：io在同一个班级？

#import('dart:html');
#import('dart:io');

class htmlIO {

  ButtonElement _aButton;

  htmlIO() {
  }

  void handlePress(Event e) {
    var connection = new HttpClient().get('www.google.com','/');
    write('made it');
  }

  void run() {
    _aButton = document.query("#aButton");
    _aButton.on.click.add(handlePress);
    write("Hello World!");
  }

  void write(String message) {
    // the HTML library defines a global "document" variable
    document.query('#status').innerHTML = message;
  }
}

void main() {
  new htmlIO().run();
}