composer require xiaohuilam/laravel-admin-select2Copy

<?php

namespace App\Admin\Controllers;

use App\Http\Controllers\Controller;
//use Encore\Admin\Form; // 废弃此行
use LaravelAdminExt\Select2\Form; // 启用此行
use App\Models\User;
use App\Models\UserResource;
use Illuminate\Support\Facades\DB;

class YourController extends Controller
{
    // ...
    protected function form()
    {
        $form = new Form(new UserResource);

        $form->select('user_id', 'User id')->match(function ($keyword) {
            /**
             * @var \Illuminate\Database\Eloquent\Builder $query 查询对象，**切记如果数据模型没有text或id属性，记得as成text和id!**
             */
            $query = User::where('name', 'LIKE', '%' . $keyword . '%')->select([DB::raw('name AS text'), 'id',]);
            return $query;
        })->text(function ($id) {
            return User::where(app(User::class)->getKeyName(), $id)->pluck('name', 'id');
        });

        $form->multipleSelect('tags', 'Tags')->match(
            function ($keyword) {
                return Tag::where('name', 'LIKE', '%' . $keyword . '%')->select([DB::raw('name AS text'), 'id',]);
            }
        )
        ->text(
            function ($id_list) {
                return Tag::whereIn(app(Tag::class)->getKeyName(), $id_list)->pluck('name', 'id');
            }
        );

        $form->text('title', 'Title');
        $form->textarea('content', 'Content');

        return $form;
    }
}Copy