js下载图片

   DownloadImgZP = imgPath => {
        const image = new Image();
        // 解决跨域 Canvas 污染问题
        image.setAttribute('crossOrigin', 'anonymous');
        image.onload = function() {
            const canvas = document.createElement('canvas');
            canvas.width = image.width;
            canvas.height = image.height;
            const context = canvas.getContext('2d');
            context.drawImage(image, 0, 0, image.width, image.height);
            const url = canvas.toDataURL('image/png'); // 得到图片的base64编码数据
            const a = document.createElement('a'); // 生成一个a元素
            const event = new MouseEvent('click'); // 创建一个单击事件
            a.download = 'img.png' || '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 = imgPath;
    };