Cocos 做关卡编辑器 文件下载

请问h5 怎么写文件下载到本地？

    /**
     * 保存本地json文件
     * @param Json json文件
     * @param FileName 文件名称
     */
    saveForWebBrowser(Json: any, FileName: string) {
        let JsonString = JSON.stringify(Json);
        //@ts-ignore
        if (cc.sys.isBrowser) {
            let textFileAsBlob = new Blob([JsonString]);
            let downloadLink = document.createElement('a');
            downloadLink.download = FileName;
            downloadLink.innerHTML = 'Download File';
            if (window.URL != null) {
                downloadLink.href = window.URL.createObjectURL(textFileAsBlob);
            }
            else {
                //@ts-ignore
                downloadLink.href = window.URL.createObjectURL(textFileAsBlob);
                downloadLink.onclick = () => {
                    document.body.removeChild(downloadLink);
                };
                downloadLink.style.display = 'none';
                document.body.appendChild(downloadLink);
            }
            downloadLink.click();
        }
    }