js 下载文件

/**
 * 下载一个文件并按指定的文件名保存
 * @param {String} url 要下载的链接
 * @param {String} fileName 保存的文件名
 */
export function downloadFile(url: string, fileName: string) {
    const el = document.createElement( "a" );
    el.style.display =  "none" ;
    el.setAttribute( "target" ,  "_blank" );
    el.href = url;
    if (fileName) {
        el.setAttribute( "download" , fileName);
    }

    document.body.appendChild(el);
    el.click();
    document.body.removeChild(el);
}