Laravel添加数据库数据时出现ArgumentCountError错误求助

错误详情 #

ArgumentCountError
调用App\Http\Requests\Admin\Categories\StoreRequest::Illuminate\Foundation\Providers{closure}()时传入参数数量不足，预期传入1个参数但实际传入0个，错误发生在E:\xampp\htdocs\cylinders\cylinders\vendor\laravel\framework\src\Illuminate\Macroable\Traits\Macroable.php第124行。

问题根源 #

错误出在控制器的store方法中：

public function store(StoreRequest $request)
{
    $validatedData = $request->validate(); // 此处是问题核心
    
    $createdCategory = Category::create([
        'title' => $validatedData['title'],
        'slug' => $validatedData['slug'],
    ]);
    
    if(!$createdCategory){
        return back()->with('failed', 'Failed to Create Category.');
    }
    return back()->with('success', 'Success to Create Category.');
}

当使用自定义FormRequest（即这里的StoreRequest）时，Laravel会自动在进入控制器方法前完成验证流程，无需手动调用$request->validate()。而validate()方法本身要求传入验证规则数组作为参数，你此处未传参，直接触发了参数不足的错误。

解决方案 #

删除多余的$request->validate()调用，改用$request->validated()获取经过验证的请求数据，修改后的控制器代码如下：

public function store(StoreRequest $request)
{
    $validatedData = $request->validated();
    
    $createdCategory = Category::create([
        'title' => $validatedData['title'],
        'slug' => $validatedData['slug'],
    ]);
    
    if(!$createdCategory){
        return back()->with('failed', 'Failed to Create Category.');
    }
    return back()->with('success', 'Success to Create Category.');
}

也可以简化为更紧凑的写法：

public function store(StoreRequest $request)
{
    $createdCategory = Category::create($request->validated());
    
    return back()->with(
        $createdCategory ? 'success' : 'failed', 
        $createdCategory ? 'Success to Create Category.' : 'Failed to Create Category.'
    );
}

其他代码验证 #

你的路由、表单和StoreRequest验证类均无问题，无需修改：

路由 #

Route::post('', [CategoriesController::class, 'store'])->name('admin.categories.store');

页面表单 #

<form action="{{ route('admin.categories.store') }}" method="post">
    @csrf
    <div class="card-body">
        <div class="row">
            <div class="col-md-6">
                <div class="form-group">
                    <label>Slug</label>
                    <input type="text" class="form-control" name="slug">
                </div>
            </div>
            <div class="col-md-6">
                <div class="form-group">
                    <label>Title</label>
                    <input type="text" class="form-control" name="title">
                </div>
            </div>
        </div>
    </div>
    <!-- /.card-body -->

    <div class="card-footer">
        <button type="submit" class="btn btn-primary float-left">Save</button>
    </div>
</form>

请求验证类 #

<?php

namespace App\Http\Requests\Admin\Categories;

use Illuminate\Foundation\Http\FormRequest;

class StoreRequest extends FormRequest
{
    /**
     * Determine if the user is authorized to make this request.
     *
     * @return bool
     */
    public function authorize()
    {
        return true;
    }

    /**
     * Get the validation rules that apply to the request.
     *
     * @return array
     */
    public function rules()
    {
        return [
            'title' => 'required|min:3|max:128|unique:categories,title',
            'slug' => 'required|min:3|max:128|unique:categories,slug',
        ];
    }
}

内容的提问来源于stack exchange，提问作者amir garmroudi