<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<div style="border:2px dashed red;">
<p>
图片上传前预览：<input type="file" id="xdaTanFileImg" οnchange="xmTanUploadImg(this)" accept="image/*"/>
<input type="button" value="隐藏图片" οnclick="document.getElementById('xmTanImg').style.display = 'none';"/>
<input type="button" value="显示图片" οnclick="document.getElementById('xmTanImg').style.display = 'block';"/>
</p>
<img id="xmTanImg"/>
<div id="xmTanDiv"></div>
</div>
<hr />
<script type="text/javascript">
//判断浏览器是否支持FileReader接口
if (typeof FileReader == 'undefined') {
document.getElementById("xmTanDiv").InnerHTML = "<h1>当前浏览器不支持FileReader接口</h1>";
//使选择控件不可操作
document.getElementById("xdaTanFileImg").setAttribute("disabled", "disabled");
}
//选择图片，马上预览
function xmTanUploadImg(obj) {
var file = obj.files[0];
console.log(obj);console.log(file);
console.log("file.size = " + file.size); //file.size 单位为byte
var reader = new FileReader();
//读取文件过程方法
reader.onloadstart = function (e) {
console.log("开始读取....");
}
reader.onprogress = function (e) {
console.log("正在读取中....");
}
reader.onabort = function (e) {
console.log("中断读取....");
}
reader.onerror = function (e) {
console.log("读取异常....");
}
reader.onload = function (e) {
console.log("成功读取....");
var img = document.getElementById("xmTanImg");
img.src = e.target.result;
//或者 img.src = this.result; //e.target == this
}
reader.readAsDataURL(file)
}
</script>
</body>
</html>
