Can'；t将内联css分配给javascript元素

我正在构建一个将div注入站点的代码。问题是，我无法通过javascript分配css值，因为它们似乎不会发生在文档上（不是全部）

var barRoot = document.createElement('DIV'); 
barRoot.style.backgroundColor='#44AA44';
barRoot.style['height']='30px';
barRoot.style['width']='100%';
barRoot.style['position']='absolute';
barRoot.style['font-size']='14px';
barRoot.style['font-family']='Arial, Helvetica, sans-serif';
barRoot.style['z-index']='99999001';
barRoot.style['font-weight']='bold';
barRoot.style['top']='0pt';
barRoot.style['left']='0pt';
barRoot.style['color']='White';
barRoot.style['padding']='0pt';
barRoot.style['margin']='0pt';
barRoot.style['border']='0px solid rgb(0, 0, 0)';
barRoot.id =  'irobRootElem1';  
document.body.insertBefore(barRoot, document.body.firstChild);  

var heartImg = document.createElement('IMG');   
heartImg.src = 'heart.png';  
heartImg.style['float']='left';  
heartImg.style['margin-left']='8px';  
heartImg.style['margin-top']='5px';  
heartImg.style['margin-right']='8px';  
barRoot.appendChild(heartImg);  

代码如下：

var barRoot = document.createElement('DIV'); 
barRoot.style.backgroundColor='#44AA44';
barRoot.style['height']='30px';
barRoot.style['width']='100%';
barRoot.style['position']='absolute';
barRoot.style['font-size']='14px';
barRoot.style['font-family']='Arial, Helvetica, sans-serif';
barRoot.style['z-index']='99999001';
barRoot.style['font-weight']='bold';
barRoot.style['top']='0pt';
barRoot.style['left']='0pt';
barRoot.style['color']='White';
barRoot.style['padding']='0pt';
barRoot.style['margin']='0pt';
barRoot.style['border']='0px solid rgb(0, 0, 0)';
barRoot.id =  'irobRootElem1';  
document.body.insertBefore(barRoot, document.body.firstChild);  

var heartImg = document.createElement('IMG');   
heartImg.src = 'heart.png';  
heartImg.style['float']='left';  
heartImg.style['margin-left']='8px';  
heartImg.style['margin-top']='5px';  
heartImg.style['margin-right']='8px';  
barRoot.appendChild(heartImg);  

---

如果希望通过JavaScript指定样式，则属性名称与CSS文件中的名称不完全相同

var barRoot = document.createElement('DIV'); 
barRoot.style.backgroundColor='#44AA44';
barRoot.style['height']='30px';
barRoot.style['width']='100%';
barRoot.style['position']='absolute';
barRoot.style['font-size']='14px';
barRoot.style['font-family']='Arial, Helvetica, sans-serif';
barRoot.style['z-index']='99999001';
barRoot.style['font-weight']='bold';
barRoot.style['top']='0pt';
barRoot.style['left']='0pt';
barRoot.style['color']='White';
barRoot.style['padding']='0pt';
barRoot.style['margin']='0pt';
barRoot.style['border']='0px solid rgb(0, 0, 0)';
barRoot.id =  'irobRootElem1';  
document.body.insertBefore(barRoot, document.body.firstChild);  

var heartImg = document.createElement('IMG');   
heartImg.src = 'heart.png';  
heartImg.style['float']='left';  
heartImg.style['margin-left']='8px';  
heartImg.style['margin-top']='5px';  
heartImg.style['margin-right']='8px';  
barRoot.appendChild(heartImg);  

检查

var barRoot = document.createElement('DIV'); 
barRoot.style.backgroundColor='#44AA44';
barRoot.style['height']='30px';
barRoot.style['width']='100%';
barRoot.style['position']='absolute';
barRoot.style['font-size']='14px';
barRoot.style['font-family']='Arial, Helvetica, sans-serif';
barRoot.style['z-index']='99999001';
barRoot.style['font-weight']='bold';
barRoot.style['top']='0pt';
barRoot.style['left']='0pt';
barRoot.style['color']='White';
barRoot.style['padding']='0pt';
barRoot.style['margin']='0pt';
barRoot.style['border']='0px solid rgb(0, 0, 0)';
barRoot.id =  'irobRootElem1';  
document.body.insertBefore(barRoot, document.body.firstChild);  

var heartImg = document.createElement('IMG');   
heartImg.src = 'heart.png';  
heartImg.style['float']='left';  
heartImg.style['margin-left']='8px';  
heartImg.style['margin-top']='5px';  
heartImg.style['margin-right']='8px';  
barRoot.appendChild(heartImg);  

但正如所建议的那样，使用类比编程设置样式更容易使用

var barRoot = document.createElement('DIV'); 
barRoot.style.backgroundColor='#44AA44';
barRoot.style['height']='30px';
barRoot.style['width']='100%';
barRoot.style['position']='absolute';
barRoot.style['font-size']='14px';
barRoot.style['font-family']='Arial, Helvetica, sans-serif';
barRoot.style['z-index']='99999001';
barRoot.style['font-weight']='bold';
barRoot.style['top']='0pt';
barRoot.style['left']='0pt';
barRoot.style['color']='White';
barRoot.style['padding']='0pt';
barRoot.style['margin']='0pt';
barRoot.style['border']='0px solid rgb(0, 0, 0)';
barRoot.id =  'irobRootElem1';  
document.body.insertBefore(barRoot, document.body.firstChild);  

var heartImg = document.createElement('IMG');   
heartImg.src = 'heart.png';  
heartImg.style['float']='left';  
heartImg.style['margin-left']='8px';  
heartImg.style['margin-top']='5px';  
heartImg.style['margin-right']='8px';  
barRoot.appendChild(heartImg);  

以下是从上面的w3链接中提取的列表：

var barRoot = document.createElement('DIV'); 
barRoot.style.backgroundColor='#44AA44';
barRoot.style['height']='30px';
barRoot.style['width']='100%';
barRoot.style['position']='absolute';
barRoot.style['font-size']='14px';
barRoot.style['font-family']='Arial, Helvetica, sans-serif';
barRoot.style['z-index']='99999001';
barRoot.style['font-weight']='bold';
barRoot.style['top']='0pt';
barRoot.style['left']='0pt';
barRoot.style['color']='White';
barRoot.style['padding']='0pt';
barRoot.style['margin']='0pt';
barRoot.style['border']='0px solid rgb(0, 0, 0)';
barRoot.id =  'irobRootElem1';  
document.body.insertBefore(barRoot, document.body.firstChild);  

var heartImg = document.createElement('IMG');   
heartImg.src = 'heart.png';  
heartImg.style['float']='left';  
heartImg.style['margin-left']='8px';  
heartImg.style['margin-top']='5px';  
heartImg.style['margin-right']='8px';  
barRoot.appendChild(heartImg);  

文档对象模型（DOM）级别2样式规范 版本1.0 W3C建议13，2000年11月

---

我会添加一个样式标签。用于设置内联样式。

您想要的结果是什么？现在绿色背景不会封装图像，因为图像向左浮动，没有高度：“不是所有的”：哪一个？这可能是有原因的。您是否考虑过只向插入的元素添加一个类，并在样式表中声明该类以及所有需要的设置。对我来说，这似乎是一个简单而有效的方法…谢谢大家，我后来确实上过课，但我只是想知道为什么它不起作用，它把我吓坏了

var barRoot = document.createElement('DIV'); 
barRoot.style.backgroundColor='#44AA44';
barRoot.style['height']='30px';
barRoot.style['width']='100%';
barRoot.style['position']='absolute';
barRoot.style['font-size']='14px';
barRoot.style['font-family']='Arial, Helvetica, sans-serif';
barRoot.style['z-index']='99999001';
barRoot.style['font-weight']='bold';
barRoot.style['top']='0pt';
barRoot.style['left']='0pt';
barRoot.style['color']='White';
barRoot.style['padding']='0pt';
barRoot.style['margin']='0pt';
barRoot.style['border']='0px solid rgb(0, 0, 0)';
barRoot.id =  'irobRootElem1';  
document.body.insertBefore(barRoot, document.body.firstChild);  

var heartImg = document.createElement('IMG');   
heartImg.src = 'heart.png';  
heartImg.style['float']='left';  
heartImg.style['margin-left']='8px';  
heartImg.style['margin-top']='5px';  
heartImg.style['margin-right']='8px';  
barRoot.appendChild(heartImg);