下载远程图片转Base64 - 苏锡波的异世仙府

<html>
<head>
head>
<body>
    <img id="img" src=""/>
    <button id="btn">下载button>
    <script>
 
        window.onload = function () {
            let btn = this.document.getElementById("btn");
            btn.onclick = function () {
                startDownload();
            };
        };
 
        function startDownload() {
            let imageURL = "http://192.168.0.100:8081/oss/posters/12345678.png";
            //imageURL = "https://cdn.glitch.com/4c9ebeb9-8b9a-4adc-ad0a-238d9ae00bb5%2Fmdn_logo-only_color.svg?1535749917189";
            downloadedImg = new Image;
            downloadedImg.crossOrigin = "Anonymous";
            downloadedImg.addEventListener("load", imageReceived, false);
            downloadedImg.src = imageURL;
        }
 
        function imageReceived() {
            let canvas = document.createElement("canvas");
            let context = canvas.getContext("2d");
 
            canvas.width = downloadedImg.width;
            canvas.height = downloadedImg.height;
 
            context.drawImage(downloadedImg, 0, 0);
 
            try {
                let data = canvas.toDataURL("image/png");
                let img = document.getElementById("img");
                img.src = data;
            }
            catch (err) {
                console.log("Error: " + err);
            }
        }
    script>
body>
html>
下载远程图片转 Base64
