<form id="file">    <input accept="audio/*" name="file" id="test" type="file" />上傳語音文件    <button style="position: absolute;bottom: 0;left: -40px;" @click="test()">上傳</button></form>var file = new FormData(document.getElementById("file"));console.log(file);https://jsfiddle.net/4g639vwz/為啥獲取不到值，打印的是空的！