外观\点火\异常\视图异常缺少[路由: trainingcategories.update]所需的参数

Question

可以seam找出问题是模型没有返回任何数据，我已经检查了控制器，视图，路由和一切似乎都是正常的。

    public function edit(TrainingCategory $trainingCategory)
    {
        return view('admin.trainingcategories.edit')->with(['trainingcategory'=>$trainingCategory]);
    }

这是我的控制器方法，$trainingCategory不从数据库返回所需的数据。

Route::prefix('admin')->middleware('is_admin')->group(function () {
    Route::get('/dashboard', 'HomeController@adminHome')->name('admin.home');
    Route::resource('positions', 'PositionsController');
    Route::resource('departments', 'DepartmentsController');
    Route::resource('trainings', 'TrainingsController');
    Route::resource('trainingcategories', 'TrainingCategoriesController');
    Route::get('/trainingcategories/{id}/{action}', 'TrainingCategoriesController@changestatus')->name('trainingcategories.status');
});

以下是我的路径文件，其中显示了代码

@extends('layouts.admin')
@section('content')
<div class="app-main__inner">
    <div class="app-page-title">
        <div class="page-title-wrapper">
            <div class="page-title-heading">
                <div class="page-title-icon">
                    <i class="pe-7s-user icon-gradient bg-mean-fruit">
                    </i>
                </div>
                <div>Edit Training Category
                    <div class="page-title-subheading">Modify.
                    </div>
                </div> 
            </div>
            <div class="page-title-actions">

                <div class="d-inline-block dropdown">
                    <a href="{{ route('trainingcategories.create') }}" type="button"  class="btn-shadow  btn btn-info">

                        Create New Training Category
                        <span class="btn-icon-wrapper pr-2 opacity-7">

                        </span>
                    </a>
                    <a href="{{ route('trainingcategories.index') }}" type="button"  class="btn-shadow  btn btn-primary">

                        List  Training Categories
                        <span class="btn-icon-wrapper pr-2 opacity-7">
                            <i class="fa fa-arrow-right fa-w-20"></i>
                        </span>
                    </a>

                </div>
            </div>
                </div>
    </div>            
   <!--Data table section-->

   <div class="row">
       <div class="col-md-12">

        <nav class="" aria-label="breadcrumb">
            <ol class="breadcrumb">
                <li class="breadcrumb-item"><a href="{{ route('admin.home') }}">Dashboard</a></li>
            <li class="breadcrumb-item"><a href="{{ route('trainingcategories.index') }}">Training Category</a></li>
                <li class="active breadcrumb-item" aria-current="page">Edit Training Category</li>
            </ol>
        </nav>
           <!--alerts-->
           @if(!empty($errors->all()) )

                          <div class="alert alert-danger fade show" role="alert">
                              @foreach ($errors->all() as $error)
                                      <li>{{ $error }}</li>     
                              @endforeach
                          </div>
            @endif
            <!--end alerts--> 
        <div class="main-card mb-3 card">
        <div class="card-body"><h3 class="h4">Edit Training Category > <b>{{ $trainingcategory->name }}</b><br>
                <small class="muted">Modify</small></h3>
                <hr>
                <form class="needs-validation" novalidate method="POST" action="{{ route('trainingcategories.update',['trainingcategory'=>$trainingcategory->id]) }}">
                    @csrf
                    @method('PUT')
                        <div class="department-relative form-group">
                            <label for="name" class="">Name</label>
                                <input name="name" id="name" placeholder="Enter training category" type="text" class="form-control" 
                                value="{{ old('name',$trainingcategory->name) }}" required>
                                <div class="valid-feedback">
                                    Looks good!
                                </div>
                                <div class="invalid-feedback">
                                    Please enter training category.
                                </div>
                            </div>
                        <div class="department-relative form-group">
                            <label for="description" class="">Active<i class="muted"></i></label>
                            @include('includes._active_select')
                            </div>
                        <div class="department-relative form-group">
                            <label for="description" class="">Training Description<i class="muted">(Optional)</i></label>
                            <textarea name="description" id="description" class="form-control" required> {{ old('description',$trainingcategory->description) }} </textarea>
                            <div class="valid-feedback">
                                Looks good!
                            </div>
                            <div class="invalid-feedback">
                                Please enter training description.
                            </div>
                        </div>
                        <button class="mt-1 btn btn-primary">update</button>
                    </form>
                </div>

        </div>
</div>
</div>
     <!-- form validation-->
<script>
// Example starter JavaScript for disabling form submissions if there are invalid fields
(function() {
'use strict';
window.addEventListener('load', function() {
// Fetch all the forms we want to apply custom Bootstrap validation styles to
var forms = document.getElementsByClassName('needs-validation');
// Loop over them and prevent submission
var validation = Array.prototype.filter.call(forms, function(form) {
form.addEventListener('submit', function(event) {
    if (form.checkValidity() === false) {
        event.preventDefault();
        event.stopPropagation();
    }
    form.classList.add('was-validated');
}, false);
});
}, false);
})();
</script>
   <!--end data table section-->


</div>

@endsection

这是我的观点

Answer 1

伙计们，我最终通过将变量名trainingCategory更改为$trainingcategory (注意小写的'c'，与资源路由命名相匹配).So资源从数据库返回数据，最终解决了这个问题。

Laravel自动解析在变量名称与路线段名称匹配的路线或控制器操作中定义的类型提示模型。

Answer 2

该错误与路由: trainingcategories.update相关。当你这样做的时候：

Route::resource('trainingcategories','TrainingCategoriesController');

您将在TrainingCategoriesController的更新方法中生成以下路由:等待$trainingcategories参数的trainingcategories.update。

如下所示：

public function update(TrainingCategory $trainingCategory)

因此，您需要查看update方法。edit方法没有受到惩罚。

Answer 3

您已经展示了如何生成路由：

route('trainingcategories.update',['trainingcategory'=>$trainingcategory->id])

您不需要传入关联数组，您可以传入模型。

route('trainingcategories.update', $trainingcategory)

确保$traningcategory实际存在，并且ID属性不为空。Laravel抱怨说它没有获得所需的参数。