检查codeigniter文件上载中允许的类型

我想在codeigniter中为我的文件创建多个上载。现在我在检查允许上传的文件类型时遇到了问题。在这里，我的控制器中有一个代码，用于检查数组中的文件是否为图像

if(!empty($_FILES['requirement_files']['name'])) {
    $allowed_types = ['image/jpeg', 'image/jpg', 'image/png'];
    if(in_array($_FILES['requirement_files']['type'], $allowed_types)) {
        $input_name = "requirement_file";
        $upload_path = "../ci_capcims/assets/img/upload/requirements";
        $pref = "".date("YmdHis").".";
        $paths = multiple_upload($input_name, $upload_path, $pref);
        print_r($paths);
    }else {
        $response['error'] = 'File type not allowed';
        $response['success']='false';
        header('Content-Type: application/json');   
    }
}else {
    $response['error'] = 'No File/s selected';
    $response['success']='false';
    header('Content-Type: application/json');
}
echo json_encode($response);

我正在选择一个PNG文件，我被困在返回不允许的文件类型的代码行的条件

if（在数组（$\u files['requirement\u files']['type']，$allowed\u types）中）

以下是我的观点/表格：

<form method='post' name="frm_attachments" id="frm_attachments_id" enctype="multipart/form-data">
    <input type="hidden" name="req_id" id="pre_adopt_child_req_id">
    <div class="form-group files">
        <label>Upload Your File </label>
        <input type="file" class="form-control" name="requirement_files[]" id="file_input" multiple="" required>
    </div>

    <div class="form-group">
        <label for="first_name">Remarks</label>
        <textarea class="form-control" rows="4" id="remarks_id" name="remarks" placeholder="Please input remarks here..." style="resize:none;" required></textarea>
    </div>
    <button type="button" class="btn btn-primary" id="submit_attached_files">Save</button>
</form>

你好，先生，谢谢你的回答。你能定义FCPATH吗；当您希望包含来自根文件夹FCPATH=C:\xampp\htdocs\your\u root\u folder\n的内容时使用，当您希望包含来自应用程序文件夹APPPATH=C:\xampp\htdocs\your\u root\u folder\application\BASEPATH=C:\xampp\htdocs\your\u root\u folder\system的内容时使用\
$(document).on('click', '#submit_attached_files', function(event){ 
    event.preventDefault();
    $(":submit").attr("disabled", true);
        var fileInput = $('#file_input')[0];            
        if( fileInput.files.length > 0 ){
            var formData = new FormData();
            $.each(fileInput.files, function(k,file){   
                formData.append('requirement_files[]', file);
            });

            var other_data = $('#frm_attachments_id').serializeArray();
            $.each(other_data,function(key,input){
                formData.append(input.name,input.value);
            });

            $.ajax({
                method: 'post',
                url: baseurl+'user/post/attach_file_in_req',
                data: formData,
                dataType: 'json',
                contentType: false,
                processData: false,
                success: function(response){
                    console.log(response);
                }
            });
        }else{
            console.log('No Files Selected');
        }
 
});

$this->load->library('upload');
$config=array();
$config['upload_path'] = FCPATH.$save_dir;
$config['allowed_types'] = 'gif|jpg|png|csv';
$config['max_size'] = $this->config->item("max_file_size");
$config['overwrite'] = true;
$config['remove_spaces'] = true;
$uploaded_files=array();
$_FILES['image_profile']['name']=$CurrentUserID.'.jpg';
foreach ($_FILES as $key => $value)
{
  if(strlen($value['name'])>0)
  {                                  
     $this->upload->initialize($config);
     if (!$this->upload->do_upload($key))
     {
        $uploaded_files[$key]=array("status"=>false,"message"=>$value['name'].': '.$this->upload->display_errors());
     }
     else
     {
        $uploaded_files[$key]=array("status"=>true,"info"=>$this->upload->data());
     }
  }
}
return $uploaded_files;