我正在尝试触发 onclick 事件。我的代码如下所示:
索引.html:
<!--
Copyright (c) 2016, <your name>. All rights reserved. Use of this source code
is governed by a BSD-style license that can be found in the LICENSE file.
-->
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta name="scaffolded-by" content="https://github.com/google/stagehand">
<title>polymer_test_project_2</title>
<!-- Add to homescreen for Chrome on Android -->
<meta name="mobile-web-app-capable" content="yes">
<link rel="icon" sizes="192x192" href="images/touch/chrome-touch-icon-192x192.png">
<!-- Add to homescreen for Safari on iOS -->
<meta name="apple-mobile-web-app-capable" content="yes">
<meta name="apple-mobile-web-app-status-bar-style" content="black">
<meta name="apple-mobile-web-app-title" content="Web Starter Kit">
<link rel="apple-touch-icon-precomposed" href="apple-touch-icon-precomposed.png">
<!-- Tile icon for Win8 (144x144 + tile color) -->
<meta name="msapplication-TileImage" content="images/touch/ms-touch-icon-144x144-precomposed.png">
<meta name="msapplication-TileColor" content="#3372DF">
<!-- Polyfill of Custom Elements and HTML Imports -->
<script src="packages/web_components/webcomponents-lite.min.js"></script>
<script defer type="application/dart" src="index.dart"></script>
<script defer src="packages/browser/dart.js"></script>
<!-- example of using a paper element -->
<link rel="import" href="packages/polymer_elements/roboto.html">
<link rel="stylesheet" href="styles.css">
</head>
<body unresolved>
<main-app></main-app>
</body>
</html>
index.dart:
// Copyright (c) 2016, <your name>. All rights reserved. Use of this source code
// is governed by a BSD-style license that can be found in the LICENSE file.
library my_project.web.index;
import 'package:polymer_test_project_2/main_app.dart';
import 'package:polymer/polymer.dart';
/// [MainApp] used!
main() async {
await initPolymer();
}
main_app.html:
<!--
Copyright (c) 2016, <your name>. All rights reserved. Use of this source code
受可以在 LICENSE 文件中找到的 BSD 样式许可证的约束。
-->
<dom-module id="main-app">
<style>
:host {
display: block;
}
</style>
<template>
<paper-input label="Type something..." value="{{text}}"></paper-input>
<p>
Text: <span>{{text}}</span><br />
Reversed: <span>{{reverseText(text)}}</span>
</p>
<my-component>
</my-component>
</template>
</dom-module>
main_app.dart:
@HtmlImport('main_app.html')
library polymer_test_project_2;
import 'dart:html';
import 'package:polymer_elements/paper_input.dart';
import 'package:polymer_elements/paper_button.dart';
import 'package:polymer/polymer.dart';
import 'package:web_components/web_components.dart';
part 'my_component.dart';
/// Uses [PaperInput]
@PolymerRegister('main-app')
class MainApp extends PolymerElement {
@property
String text;
MyComponent myComponent;
/// Constructor used to create instance of MainApp.
MainApp.created() : super.created();
@reflectable
String reverseText(String text) {
return text.split('').reversed.join('');
}
}
my_component.html:
<dom-module id="my-component">
<template>
<span>foobar</span>
<span>{{text}}</span>
<paper-button on-click="{{ settext }}">setText</paper-button>
</template>
</dom-module>
和 my_component.dart:
@HtmlImport('my_component.html')
polymer_test_project_2 的一部分；
@PolymerRegister('my-component')
class MyComponent extends PolymerElement {
@property
String text="hello";
MyComponent.created() : super.created() {
print("mycomponent created");
}
@Listen('settext')
void setText([_, __]) {
print("text set to goodbye");
text="goodbye";
}
}
目前，按钮显示在我的组件中，但是当我点击按钮时，错误消息来了:
[my-component::_createEventHandler]: listener method `{{ settext }}` not defined
有人知道我怎样才能让它工作吗？ :)
提前谢谢了!
最佳答案
对于事件绑定(bind)，不要使用 {{...}} ，这仅用于值绑定(bind)。 on-已经表明 Polymer 事件绑定(bind)和事件绑定(bind)只允许在任何地方使用函数名称，因此这就是所有必要的:
<paper-button on-click="settext">setText</paper-button>
关于嵌套元素中的 Dartlang polymer 点击事件，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/37414340/