無法讀取NULL屬性

Question

我有以下html文件，其中我嘗試使用網絡工作者突出顯示一些代碼：

 <link rel="stylesheet" href="./highlight/styles/default.css"> <script src="./highlight/highlight.pack.js"></script> <script src="http://code.jquery.com/jquery-1.11.0.min.js"></script> <script> if (typeof(Worker) !== "undefined") { addEventListener('load', function() { var code = document.querySelector('#code'); var worker = new Worker('worker.js'); worker.onmessage = function(event) { code.innerHTML = event.data; } worker.postMessage(code.textContent); }) } else { } </script> <pre><code> // This is a generated file with many packages `ifdef MACRO_1 `else package pkg_1; typedef logic [1:0] t; typedef enum t { IDLE = 2'd0 , ARMED = 2'd1 , WRITE = 2'd2 , BUSY = 2'd3 } e; </code></pre> 

但是我收到一條錯誤消息：Uncaught TypeError：無法讀取null的屬性'textContent'（worker.postMessage（content.textContent））;

有解決方案嗎？

Answer 1

在代碼元素上添加id =“ code”屬性： https : //jsbin.com/daqijafoca/edit?html，輸出

<link rel="stylesheet" href="./highlight/styles/default.css">
<script src="./highlight/highlight.pack.js"></script>

<script src="http://code.jquery.com/jquery-1.11.0.min.js"></script>
<script>

    if (typeof(Worker) !== "undefined") {

        addEventListener('load', function() {
            var code = document.querySelector('#code');
            var worker = new Worker('worker.js');
            worker.onmessage = function(event) { code.innerHTML = event.data; }
            worker.postMessage(code.textContent);
        })

    } else {
    }


</script>


<pre><code id="code">
// This is a generated file with many packages
`ifdef MACRO_1
`else
package pkg_1;
  typedef logic [1:0] t;
  typedef enum t {
      IDLE = 2'd0
    , ARMED = 2'd1
    , WRITE = 2'd2
    , BUSY = 2'd3
  } e;
</code></pre>