<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>document</title>
<script>
function myFunction() {
console.log("myFunction")
var img = document.getElementById("testImg");
console.log(img.src)
btnImg(img.src, "图片名字")
}
function btnImg(imgsrc, name) {
let image = new Image();
// 解决跨域 Canvas 污染问题
image.setAttribute("crossOrigin", "anonymous");
image.onload = function () {
let canvas = document.createElement("canvas");
canvas.width = image.width;
canvas.height = image.height;
let context = canvas.getContext("2d");
context.drawImage(image, 0, 0, image.width, image.height);
let url = canvas.toDataURL("image/png"); //得到图片的base64编码数据
let a = document.createElement("a"); // 生成一个a元素
let event = new MouseEvent("click"); // 创建一个单击事件
a.download = name || "photo"; // 设置图片名称
a.href = url; // 将生成的URL设置为a.href属性
a.dispatchEvent(event); // 触发a的单击事件
};
image.src = imgsrc;
};
</script>
</head>
<body>
<img src="xxxx" width="90%" id="testImg">
<button onclick="myFunction()">点我</button>
<p id="demo"></p>
</body>
</html>
html + js 下载图片