javascript - 如何将 html 文本放在 Canvas 图表的顶部？

Question

这是我的简单 jsFiddle .我希望将 HTML 文本放在 float 图表的顶部。或者将图表放在背景中(取决于您的想法)。

HTML:

<div id="wrapper">
  <h1>Place me on top please. How?!</h1>
  <div id="placeholder"></div>
</div>

CSS:

#wrapper { position:relative; }
h1 { z-index:100; color:blue; font-size:5em; margin:0; line-height:0.9em; }
#placeholder {
    width:500px;
    height:300px;
    position:absolute;
    top:0;
    left:0;
    z-index:1;
}

JS(其余部分参见 jsFiddle):

$(document).ready(function(){
    chart = $.plot($("#placeholder"),data,options);
});

Answer 1

您应该将 position: absolute; 添加到您的 css 中的 h1...

Note: z-index only works on positioned elements (position:absolute, position:relative, or position:fixed).

source of this quoted text

#wrapper { position:relative; }
h1 { z-index:100; color:blue; position: absolute; font-size:5em; margin:0; line-height:0.9em; }
#placeholder {
    width:500px;
    height:300px;
    position:absolute;
    top:0;
    left:0;
    z-index:1;
}

:::: JSFIDDLE ::::