drb/app/Exports/TableHeadExport.php

<?php

namespace App\Exports;

use Illuminate\Support\Collection;
use Maatwebsite\Excel\Concerns\FromCollection;
use Maatwebsite\Excel\Concerns\WithCustomValueBinder;
use Maatwebsite\Excel\Concerns\WithHeadings;
use Maatwebsite\Excel\Concerns\WithStrictNullComparison;
use Maatwebsite\Excel\Concerns\WithEvents;
use Maatwebsite\Excel\Events\AfterSheet;
use PhpOffice\PhpSpreadsheet\Cell\DefaultValueBinder;
use PhpOffice\PhpSpreadsheet\Cell\Coordinate;

class TableHeadExport extends DefaultValueBinder implements
    WithCustomValueBinder,
    FromCollection,
    WithStrictNullComparison,
    WithHeadings,
    WithEvents
{
    protected $data;
    protected $headers;
    protected $headerComments; // 表头批注：键=表头名，值=批注内容

    public function __construct($data, $headers = [], $headerComments = [])
    {
        $this->data = $data;
        $this->headers = $headers;
        $this->headerComments = $headerComments;
    }

    public function collection()
    {
        return new Collection($this->createData());
    }

    public function createData()
    {
        return $this->export();
    }

    public function headings(): array
    {
        return $this->headers;
    }

    private function export()
    {
        $list = [];
        foreach ($this->data as $v) {
            $list[] = $v;
        }
        return $list;
    }

    public function registerEvents(): array
    {
        return [
            AfterSheet::class => function(AfterSheet $event) {
                if (empty($this->headerComments)) {
                    return; // 不传就不加批注
                }

                $sheet = $event->sheet->getDelegate();

                foreach ($this->headers as $index => $headerName) {
                    if (!isset($this->headerComments[$headerName])) {
                        continue; // 该表头没设置批注
                    }

                    $columnLetter = \PhpOffice\PhpSpreadsheet\Cell\Coordinate::stringFromColumnIndex($index + 1);
                    $cell = $columnLetter . '1';

                    $commentText = $this->headerComments[$headerName];

                    // 创建批注
                    $comment = $sheet->getComment($cell);
                    $comment->getText()->createTextRun($commentText);
                    $comment->setAuthor('系统提示');

                    // 设置批注框大小（可调整数值）
                    $comment->setWidth('200pt');   // 宽度
                    $comment->setHeight('100pt');  // 高度
                }
            }
        ];
    }

}