参考：https://blog.csdn.net/milijiangjun/article/details/79723013
<!DOCTYPE html>
<html lang="zh_CN">
<head>
<meta charset="UTF-8">
<title>CSS样式:点击图片上传文件</title>
<!-- 引入样式 -->
<!--<link rel="stylesheet" type="text/css" href="css/style.css">-->
<style type="text/css">
/*定义图像以及大小*/
.imageFileInput {
200px;
height: 200px;
position: absolute;
background-color: red;
/*这里可以换成图片路径（background-image：../img/....）注意图片路径*/
}
/*定义上传*/
.fileInput {
height: 100%;
position: absolute;
right: 0;
top: 0;
opacity: 0;
}
</style>
</head>
<body>
<div class="imageFileInput" id="result">
<!--<input class="fileInput" type="file" id="" name="">-->
<input type="file" id="file" class="fileInput" name="file" />
<div id="result"></div>
</div>
</body>
</html>
<script src="http://libs.baidu.com/jquery/2.0.0/jquery.min.js"></script>
<script type="text/javascript">
function ProcessFile(e) {
var file = document.getElementById('file').files[0];
if(file) {
var reader = new FileReader();
reader.onload = function(event) {
var txt = event.target.result;
var img = document.createElement("img");
img.src = txt; //将图片base64字符串赋值给img的src
// console.log(txt);
// document.getElementById("result").appendChild(img);
$('#result').css("background-image", "url(" + txt + ")");
};
}
reader.readAsDataURL(file);
}
function contentLoaded() {
document.getElementById('file').addEventListener('change',
ProcessFile, false);
}
window.addEventListener("DOMContentLoaded", contentLoaded, false);
</script>