解决linux导出excel报错的问题

extend/service/PhpSpreadsheetService.php

@@ -119,6 +119,7 @@ class PhpSpreadsheetService
             }
 
         }
+        if(ob_get_length()) ob_end_clean();
         //header('Content-Type: application/vnd.ms-excel');xls
         header('Content-Type:application/vnd.openxmlformats-officedocument.spreadsheetml.sheet');//xlsx
         header('Content-Disposition: attachment;filename="' . $filename . '"');