laravel-5.8:为foreach()提供的参数无效

Question

您好，我用Laravel制作了一个表单来上传照片，但当我打开表单时，它显示错误:为foreach()提供的参数无效。

刀片文件：

<form method="POST" action="{{ route('admin.product.alternateimages') }}" enctype="multipart/form-data" class="add-new-post">
    @csrf
    <strong class="text-muted d-block mb-2 mt-5">Upload Product Image</strong>
    <div class="input-group mb-3">
      <div class="input-group input-group-seamless">
        <input type="file" name="product_alt_img[]" class="form-control mb-2 btn btn-sm btn-outline-primary mr-1 @error('product_image') is-invalid @enderror" value="{{ old('product_image') }}" id="" placeholder=""> </div>
        @error('product_image')
          <div class="small text-danger">{{ $message }}</div>
        @enderror
    </div>
</form>

功能：

    public function alternateimages(Request $request)
    {
        $altimgs = new Product;
        $altimgs->product_id = $request->product_id;
        $files = $request->file('product_alt_img');
        foreach ($files as $file) {
          $images = $file->getClientOriginalName();
          $file->move(public_path('images/backend_images/product_images'), $images);
          $altimgs->product_alt_img = $images;
        }
        $altimgs->save();

        return redirect()->back()->with('flash_message_success', 'Product Images has been added successfully');   
    }

Answer 1

如果要上载单个文件，则可能需要将product_alt_img[]更改为product_alt_img。

<input type="file" name="product_alt_img" class="form-control mb-2 btn btn-sm btn-outline-primary mr-1 @error('product_image') is-invalid @enderror" value="{{ old('product_image') }}" id="" placeholder="">

否则，如果希望上传多个文件，您可能必须修改控制器方法。

 public function alternateimages(Request $request)
{
    $altimgs = new Product;
    $altimgs->product_id = $request->product_id;

    //fetch an array of product_alt_img
    $files = $request->product_alt_img;

    //go over each Illuminate\Http\UploadedFile instance
    foreach($files as $file)
    {
        $image = $file->getClientOriginalName();

        ....
    }

    ....  
}

注:一个更有说服力的解决方案是有一个单独的表来存储产品图像