前端实现下载图片

背景：一般使用a标签，但浏览器有时候不会下载，会打开新的标签页，很不友好

下面这段代码可以实现浏览器下载图片

function downPic(src,imgName) {
        var canvas = document.createElement('canvas');
        var img = document.createElement('img');
        img.onload = function(e) {
            canvas.width = img.width;
            canvas.height = img.height;
            var context = canvas.getContext('2d');
            context.drawImage(img, 0, 0, img.width, img.height);
            canvas.getContext('2d').drawImage(img, 0, 0, img.width, img.height);
            canvas.toBlob((blob) => {
                    var link = document.createElement('a');
                    link.href = window.URL.createObjectURL(blob);
                    link.download = imgName;
                    link.click();
                },
                "image/jpeg");
        };
        img.crossOrigin = "Anonymous";
        img.src = src;
    }