Canvas保存为图片_js 将canvas生成图片保存

function save(n) {
    const canvas = document.getElementsByTagName('canvas')[0],
        // canvas的base64编码数据
        dataURL = canvas.toDataURL('image/png'),
        // 因为图片文件过大时，Blob就不会因为浏览器上下载失败
        src = dataURLtoBlob(dataURL), 
        name = n + ".png";
    // IE 
    if (window.navigator.msSaveOrOpenBlob) {
        navigator.msSaveBlob(src, name);
    } else {
        const link = document.createElement("a");
        link.setAttribute("href", window.URL.createObjectURL(src));
        link.setAttribute("download", name);
        document.body.appendChild(link);
        link.click();
    }
 
    function dataURLtoBlob(dataurl) {
        constarr = dataurl.split(','),
            mime = arr[0].match(/:(.*?);/)[1],
            byte = atob(arr[1]),
            n = byte .length,
            u8arr = new Uint8Array(n);
        while (n--) {
            u8arr[n] = byte .charCodeAt(n);
        }
        return new Blob([u8arr], { type: mime });
    }
}