无法读取NULL的属性 [英] Cannot read property of NULL

问题描述

我有以下html文件，我试图用web worker强调一些代码：

 < link rel =stylesheethref =./ 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> //这是生成的文件包含许多包``ifdef MACRO_1`elsepackage pkg_1; typedef逻辑[1：0] t; typedef enum t {IDLE = 2'd0，ARMED = 2'd1，WRITE = 2'd2，BUSY = 2'd3} e;< / code>< / pre>   
 
但是我得到一个错误：Uncaught TypeError：无法读取属性'textContent'为null（worker.postMessage（ content.textContent））; 
 
 
是否有解决方案？
解决方案
在代码元素上添加id =code属性： https://jsbin.com/daqijafoca/编辑？html，输出 
 < link rel =stylesheethref =./ 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）{
 $ b 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> 
 //这是一个包含许多软件包的生成文件
`ifdef MACRO_1 
`else 
 package pkg_1; 
 typedef逻辑[1：0] t; 
 typedef enum t {
 IDLE = 2'd0 
，ARMED = 2'd1 
，WRITE = 2'd2 
，BUSY = 2'd3 
} e; 
< / code>< / pre> 
  
 
I have the following html file in which I try to highlight some code using a web worker:



<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>





But I get an error saying: Uncaught TypeError: Cannot read property 'textContent' of null (worker.postMessage(content.textContent));

Is there a solution?
解决方案
Add id="code" attribute on code element: https://jsbin.com/daqijafoca/edit?html,output
<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>


                        
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