致命错误：“中断”不在函数中的“循环”或“切换”上下文中.php

我正在尝试PHPExcel，当我执行脚本时，我在输出中遇到错误：

致命错误：“中断”不在 /opt/lampp/htdocs/Xlsphp/test/Classes/PHPExcel/Computing/Functions 中的“loop”或“switch”上下文中.php第 581 行

我不知道我在PHP脚本中做错了什么。似乎一切都是正确的。

有没有人知道如何解决它？

这是我的PHP脚本：

<?php
require_once 'Classes/PHPExcel.php';
require_once 'config.php';

$sql = 'SELECT * FROM tablevalues';
$result = mysqli_query($conn, $sql) or die(mysqli_error($conn));
$fileName = 'test.xls';

// initialise excel column name
// currently limited to queries with less than 27 columns
$columnArray = array("A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z");

// Instantiate a new PHPExcel object
$objPHPExcel = new PHPExcel();
// Set the active Excel worksheet to sheet 0
$objPHPExcel->setActiveSheetIndex(0);
// Initialise the Excel row number
$rowCount = 1;
// fetch result set column information
$finfo = mysqli_fetch_fields($result);
// initialise columnlenght counter
$columnlenght = 0;
foreach ($finfo as $val) {
    // set column header values
    $objPHPExcel->getActiveSheet()->SetCellValue($columnArray[$columnlenght++] . $rowCount, $val->name);
}
// make the column headers bold
$objPHPExcel->getActiveSheet()->getStyle($columnArray[0]."1:".$columnArray[$columnlenght]."1")->getFont()->setBold(true);

$rowCount++;
// Iterate through each result from the SQL query in turn
// We fetch each database result row into $row in turn

while ($row = mysqli_fetch_array($result, MYSQLI_NUM)) {
    for ($i = 0; $i < $columnlenght; $i++) {
        $objPHPExcel->getActiveSheet()->SetCellValue($columnArray[$i] . $rowCount, $row[$i]);
    }
    $rowCount++;
}
// set header information to force download
header('Content-type: application/vnd.ms-excel');
header('Content-Disposition: attachment; filename="' . $fileName . '"');
// Instantiate a Writer to create an OfficeOpenXML Excel .xlsx file
// Write the Excel file to filename some_excel_file.xlsx in the current directory
$objWriter = new PHPExcel_Writer_Excel2007($objPHPExcel);
// Write the Excel file to filename some_excel_file.xlsx in the current directory
$objWriter->save('php://output');

mysqli_close($conn);
?>