js 下载文件重命名

<a  href="javascript:void(0)" title="下载" onclick="downloadCros('url地址','文件名称')"></a>


function getBlob(url) {
    return new Promise(resolve => {
        const xhr = new XMLHttpRequest();

        xhr.open('GET', url, true);
        xhr.responseType = 'blob';
        xhr.onload = () => {
            if (xhr.status === 200) {
                resolve(xhr.response);
            }
        };

        xhr.send();
    });
}

function saveAs(blob, filename) {
    if (window.navigator.msSaveOrOpenBlob) {
        navigator.msSaveBlob(blob, filename);
    } else {
        const link = document.createElement('a');
        const body = document.querySelector('body');

        link.href = window.URL.createObjectURL(blob);
        link.download = filename;

        // fix Firefox
        link.style.display = 'none';
        body.appendChild(link);

        link.click();
        body.removeChild(link);

        window.URL.revokeObjectURL(link.href);
    }
}

/**
 * 下载
 * @param  {String} url 目标文件地址
 * @param  {String} filename 想要保存的文件名称
 */
function downloadCros(url, filename) {
    getBlob(url).then(blob => {
        saveAs(blob, filename);
    });
}