扩展dart:html类;按钮元素“;飞镖
我试图扩展一个扩展dart:html类;按钮元素“;飞镖,html,dart,dart-polymer,Html,Dart,Dart Polymer,我试图扩展一个,但到目前为止没有成功。 我做错了什么。我正在使用Dart编辑器+SDK 1.5.2 在pubspec.yaml中,聚合物的版本设置为: polymer: ">=0.11.0 <0.12.0" 查看/ext_button.html <!DOCTYPE html> <html> <head> <!-- <script src="packages/web_components/platform.js">&
,但到目前为止没有成功。
我做错了什么。我正在使用Dart编辑器+SDK 1.5.2
在pubspec.yaml中,聚合物的版本设置为:
polymer: ">=0.11.0 <0.12.0"
查看/ext_button.html
<!DOCTYPE html>
<html>
<head>
<!-- <script src="packages/web_components/platform.js"></script>
not necessary anymore with Polymer >= 0.14.0 -->
<script src="packages/web_components/dart_support.js"></script>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Extended Button - Dart v1.5.2</title>
<!--Extended Button-->
<link rel="import" href="view/ext_button.html" />
</head>
<body>
<button is="ext-button">Test Button</button>
<script type="application/dart">export "package:polymer/init.dart";</script>
</body>
</html>
<!DOCTYPE html>
<link rel="import" href="packages/polymer/polymer.html">
<polymer-element name="ext-button" extends="button">
<template>
</template>
<script type="application/dart" src="ext_button.dart"></script>
</polymer-element>
<!DOCTYPE html>
<link rel="import" href="packages/polymer/polymer.html">
<polymer-element name="ext-button" extends="button">
<template>
<content></content>
</template>
<script type="application/dart" src="ext_button.dart"></script>
</polymer-element>
因此,上面的代码不起作用,但只要像下面那样编写它(只是为了验证ext按钮是否起作用),它就会告诉我以下内容:
“web/index.html:20:7:自定义元素“ext-button”从“button”扩展而来,但此标记将不包括“button”的默认属性。
要解决此问题,请将此标记写为
,或从自定义元素声明中删除“extends”属性。”
测试按钮
所以有点困惑;-)我认为解决方法简单易行,但我看不出问题所在-(在我看来,你错过了以下几点:
- 在自定义元素构造函数中调用
polymerCreated()
- 和
用聚合物扩展按钮元件
已经有类似的问题了。等我有更多时间的时候我会查一下。也许你自己也能找到。如果你找到了,请添加一个带有链接的评论。以上两件事解决了问题,仅供参考。 这里是更新的部分,现在它的工作 查看/ext_按钮。省道
import "dart:html";
import "package:polymer/polymer.dart";
@CustomTag("ext-button")
class ExtButton extends ButtonElement {
ExtButton.created() : super.created();
factory ExtButton(){
onClick.listen(clicked);
}
void clicked(MouseEvent e){
print("Ext-Button clicked");
}
}
import "dart:html";
import "package:polymer/polymer.dart";
@CustomTag("ext-button")
class ExtButton extends ButtonElement with Polymer {
ExtButton.created() : super.created()
{
polymerCreated();
onClick.listen(clicked);
}
void clicked(MouseEvent e){
print("Ext-Button clicked");
}
}
查看/ext_button.html
<!DOCTYPE html>
<html>
<head>
<!-- <script src="packages/web_components/platform.js"></script>
not necessary anymore with Polymer >= 0.14.0 -->
<script src="packages/web_components/dart_support.js"></script>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Extended Button - Dart v1.5.2</title>
<!--Extended Button-->
<link rel="import" href="view/ext_button.html" />
</head>
<body>
<button is="ext-button">Test Button</button>
<script type="application/dart">export "package:polymer/init.dart";</script>
</body>
</html>
<!DOCTYPE html>
<link rel="import" href="packages/polymer/polymer.html">
<polymer-element name="ext-button" extends="button">
<template>
</template>
<script type="application/dart" src="ext_button.dart"></script>
</polymer-element>
<!DOCTYPE html>
<link rel="import" href="packages/polymer/polymer.html">
<polymer-element name="ext-button" extends="button">
<template>
<content></content>
</template>
<script type="application/dart" src="ext_button.dart"></script>
</polymer-element>