聚合物铁选择器多选器未出现

Question

我正在尝试 <iron-selector> multi select 的简单测试。我运行元素附带的演示项目似乎从那里工作正常，但每当我将它复制到我的项目时，元素都不会出现。我做了一个 Plunker 来测试它：Plnkr test link。我正在尝试测试 multi select 选项（设置和获取 selected-values）。

<!DOCTYPE html>
<html>

<head>
  <link rel="stylesheet" href="style.css">
  <script src="script.js"></script>
  <script src="https://cdn.rawgit.com/download/polymer-cdn/2.3.1/lib/webcomponentsjs/webcomponents-lite.js"></script>
  <link rel="import" href="https://cdn.rawgit.com/download/polymer-cdn/2.3.1/lib/paper-toast/paper-toast.html">
  <link rel="import" href="https://cdn.rawgit.com/download/polymer-cdn/2.3.1/lib/iron-selector/iron-selector.html">

</head>

<body>
  <p>Start:</p>
  <iron-selector multi selected-values="[0,2]">
    <div>Item 0</div>
    <div>Item 1</div>
    <div>Item 2</div>
    <div>Item 3</div>
    <div>Item 4</div>
  </iron-selector>
  <p>End:</p>

  <paper-toast text="Polymer is working!" opened></paper-toast>

</body>

</html>

Answer 1

您似乎只是忘记设置所选元素的样式。例如，您可以将所选元素的背景样式设置为浅灰色：

<style>
  .iron-selected {
    background: #eee;
  }
</style>

demo

聚合物铁选择器多选器未出现

polymer iron-selector multi selector not appearing

polymer

polymer-2.x