<"./Export.php";
//测试数据
$headerList= ['列名1','列名2','列名3'];
$data = [
  ['值1','值2','值3'],
  ['值11','值22','值33'],
  ['值111','值222','值333']
];
$fileName = "测试导出文件名";
$tmp = ['备份字段1','备份值1','','备份字段2','备份值2'];
$export = new Export();
$result = $export->exportToCsv($headerList,$data,$fileName,$tmp);

<"\t"
   **/
  public function exportToCsv($headerList = [] , $data = [] , $fileName = '' , $tmp = []){
    //文件名称转码
    $fileName = iconv('UTF-8', 'GBK', $fileName);
    //设置header头
    header('Content-Type: application/vnd.ms-excel');
    header('Content-Disposition: attachment;filename=' . $fileName . '.csv');
    header('Cache-Control: max-age=0');
    //打开PHP文件句柄,php://output,表示直接输出到浏览器
    $fp = fopen("php://output","a");
    //备用信息
    foreach ($tmp as $key => $value) {
      $tmp[$key] = iconv("UTF-8", 'GBK', $value);
    }
    //使用fputcsv将数据写入文件句柄
    fputcsv($fp, $tmp);
    //输出Excel列表名称信息
    foreach ($headerList as $key => $value) {
      $headerList[$key] = iconv('UTF-8', 'GBK', $value);//CSV的EXCEL支持BGK编码，一定要转换，否则乱码
    }
    //使用fputcsv将数据写入文件句柄
    fputcsv($fp, $headerList);
    //计数器
    $num = 0;
    //每隔$limit行，刷新一下输出buffer,不要太大亦不要太小
    $limit = 100000;
    //逐行去除数据,不浪费内存
    $count = count($data);
    for($i = 0 ; $i < $count ; $i++){
      $num++;
      //刷新一下输出buffer，防止由于数据过多造成问题
      if($limit == $num){
        ob_flush();
        flush();
        $num = 0;
      }
      $row = $data[$i];
      foreach ($row as $key => $value) {
        $row[$key] = iconv('UTF-8', 'GBK', $value);
      }
      fputcsv($fp, $row);
    }
  }
}