导出 Excel

this.dataSource.data 是个数组，每一个元素是 table 里的一行

思路就是：每个表格元素 列 后面加 ',' 每个表格元素 行后面加 '\n' 然后把数据拼接成字符串 targetTable

exportTable() {
        let targetTable = '用户昵称,被邀请码,用户电话,实际邀请人数,总邀请人数,查询时的时间\n';
        for (let i = 0; i < this.length; i++) {
            targetTable += this.dataSource.data[i].nickname + ',';
            targetTable += this.dataSource.data[i].from_code + ',';
            targetTable += this.dataSource.data[i].phone + ',';
            targetTable += this.dataSource.data[i].real_invite_count + ',';
            targetTable += this.dataSource.data[i].total_invite_count + ',';
            targetTable += this.dataSource.data[i].now_time + '\n';
        }

        targetTable = unescape(encodeURIComponent(targetTable));  // support chinese
        if (this.length > 0) {
            const a = document.createElement('a');
            a.href = `data:application/vnd.ms-excel;base64,${btoa(targetTable)}`;
            a.download = 'inviteRank.csv';
            a.click();
        }
    }