<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>圖片上傳</title>
</head>
<body>
<!-- 要將父布局的position設置為relative，父布局將無法包裹input -->
<div style="position: relative;">
<!--設置input的position為absolute，使其不按文檔流排版，並設置其包裹整個布局 -->
<!-- 設置opactity為0，使input變透明 -->
<!-- 只接受jpg，gif和png格式 -->
<input id="upload-input" style="position: absolute; top: 0; bottom: 0; left: 0;right: 0; opacity: 0;" type="file" accept="image/gif, image/jpg, image/png" onchange="showImg(this)" multiple />
<!-- 自定義按鈕效果 -->
<div style="text-align: top">
<span style="font-size: 12px;">上傳文件：</span>
<img id="upload" src="./upload.png" style="width: 40px; height: 40px; vertical-align: middle;" />
</div>
</div>
<div id="imgContainer" style="margin-top: 10px;"></div>
</body>
<script type="text/javascript">
function showImg(obj) {
var files = obj.files
// document.getElementById("imgContainer").innerHTML = getImgsByUrl(files)
getImgsByFileReader(document.getElementById("imgContainer"), files)
}
// 使用window.URL.createObjectURL(file)讀取file實例並顯示圖片
function getImgsByUrl(files) {
var elements = ''
for (var i = 0; i < files.length; i++) {
var url = window.URL.createObjectURL(files[i])
elements += "<img src='"+ url + "' style='width: 40px; height: 40px; vertical-align: middle; margin-right: 5px;' />"
}
return elements
}
// 使用FileReader讀取file實例並顯示圖片
function getImgsByFileReader(el, files) {
for (var i = 0; i < files.length; i++) {
let img = document.createElement('img')
img.setAttribute('style', 'width: 40px; height: 40px; vertical-align: middle; margin-right: 5px;')
el.appendChild(img)
var reader = new FileReader()
reader.onload = function(e) {
img.src = e.target.result
}
reader.readAsDataURL(files[i])
}
}
</script>
</html>
