事件Jquery中的dart

Question

我试图在Jquery元素的侦听器函数中获取事件对象。我实际上正在用dart语言编程，并使用js包(dart:js)，这里有一个例子：

Example.html：

<script async type="application/dart" src="Example.dart"></script>
<script async src="packages/browser/dart.js"></script>
<link rel="stylesheet" href="//code.jquery.com/ui/1.11.1/themes/smoothness/jquery-ui.css">
<script src="//code.jquery.com/jquery-1.10.2.js"></script>
<script src="//code.jquery.com/ui/1.11.1/jquery-ui.js"></script>

<div id="container">
  <canvas id="stage" width="500px" height="500px"></canvas>
</div>
<div id="menu">
  <button id="btnImport">Button Import</button>
  <div id="slider-1"></div>
</div>

Example.dart：

import 'dart:html';
import 'dart:js' as js;

void main() {
  js.JsObject slider_1 = js.context.callMethod("\$", ['#slider-1']);
  slider_1.callMethod('slider');
  slider_1.callMethod("on",["slidechange",_onSliderChange]);
}

void _onSliderChange(js.JsObject obj1,js.JsObject obj2) {

}

如何在_onSliderChange函数中检索滑行事件的事件对象？JsOjbect真的帮不了我..。Ty

Answer 1

如果我正确理解，您就无法检索事件本身，而只能检索jquery事件的js版本(不是本机dom事件)，因此您需要了解根据http://api.jqueryui.com/slider/#event-change中的文档读取所需属性的情况。

void _onSliderChange(js.JsObject obj1, js.JsObject obj2) {
  print(obj1['target']); // <= get the div
  print(obj2['value']);  // <= get the value
}

当你移动滑块时，它应该显示如下

div (:1)
5 (:1)

正如您所说，有时很难处理/调试JsObject，因此我编写了一些帮助程序，将这些对象转换为省道集合(列表或地图)，以便在这里进行调试( converter.dart )。

void _onSliderChange(js.JsObject obj1,js.JsObject obj2) {
  print(jsObjectKeys(obj1));
  print(jsObjectAsCollection(obj1));
}

它应该显示类似的东西

[originalEvent, type, isDefaultPrevented, timeStamp, jQuery110207535289276856929, target, toElement, screenY, screenX, pageY, pageX, offsetY, offsetX, fromElement, clientY, clientX, buttons, button, which, view, shiftKey, relatedTarget, metaKey, eventPhase, currentTarget, ctrlKey, cancelable, bubbles, altKey, delegateTarget, handleObj, data, isTrigger, namespace, namespace_re, result] (:1)
{originalEvent: {originalEvent: Instance of 'MouseEvent', type: mouseup, isDefaultPrevented: {}, timeStamp: 1409328507659, jQuery110207535289276856929: true, toElement: span, screenY: 624, screenX: 115, pageY: 545, pageX: 110, offsetY: 16, offsetX: 15, fromElement: null, clientY: 545, clientX: 110, buttons: null, button: 0, which: 1, view: <window>, target: span, shiftKey: false, relatedTarget: null, metaKey: false, eventPhase: 3, currentTarget: Instance of 'HtmlDocument', ctrlKey: false, cancelable: true, bubbles: true, altKey: false, delegateTarget: Instance of 'HtmlDocument', handleObj: {type: mouseup, origType: mouseup, data: null, handler: {guid: 23}, guid: 23, selector: null, needsContext: null, namespace: slider}, data: null}, type: slidechange, isDefaultPrevented: {}, timeStamp: 1409328507659, jQuery110207535289276856929: true, target: div, toElement: span, screenY: 624, screenX: 115, pageY: 545, pageX: 110, offsetY: 16, offsetX: 15, fromElement: null, clientY: 545, clientX: 110, buttons: null, button: 0, which: 1, view: <window>, shiftKey: false, relatedTarget: null, metaKey: false, eventPhase: 3, currentTarget: div, ctrlKey: false, cancelable: true, bubbles: true, altKey: false, delegateTarget: div, handleObj: {type: slidechange, origType: slidechange, data: null, handler: {guid: 17}, guid: 17, selector: null, needsContext: null, namespace: }, data: null, isTrigger: 3, namespace: , namespace_re: null, result: null} (:1)

在那里您可能可以从事件中找到您想要的属性。