實現代碼：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=gb2312" /><title>js圖片預覽功能</title><script language=javascript>function previewFile() { var preview = document.querySelector('img'); var file = document.querySelector('input[type=file]').files[0]; var reader = new FileReader(); reader.onloadend = function () { preview.src = reader.result; } if (file) { reader.readAsDataURL(file); } else { preview.src = ""; }}</script></head><body><input type="file" onchange="previewFile()"><br><img src="" height="200" width="300" alt="Image preview..."/></body></html>
效果預覽
效果圖：
以上這篇如何通過js實現圖片預覽功能【附執行個體代碼】就是小編分享給大家的全部內容了，希望能給大家一個參考，也希望大家多多支援雲棲社區。
Start building with 50+ products and up to 12 months usage for Elastic Compute Service
1 on 1 presale consultation
24/7 Technical Support 6 Free Tickets per Quarter Faster Response
Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.
A comprehensive suite of global cloud computing services to power your business
Payment Methods We Support
