我無法在我的 codeigniter 上上傳圖片或 pdf這是我的看法 <div class="form-group">        <label>Upload Gambar</label>        <input name="foto" type="file" class="form-control">    </div>這是我的控制器 function form_pendaftaran_act(){    $nik = $this->input->post('nik');    $nama = $this->input->post('nama_anggota');    $gender = $this->input->post('gender');    $ttl = $this->input->post('ttl');    $email = $this->input->post('email');    $notelp = $this->input->post('notelp');    $alamat = $this->input->post('alamat');    $pendidikan = $this->input->post('pendidikan');    $status = $this->input->post('status');    $tinggi_badan = $this->input->post('tinggi_badan');    $berat_badan = $this->input->post('berat_badan');    $uk_baju = $this->input->post('uk_baju');    $uk_celana = $this->input->post('uk_celana');    $posisi = $this->input->post('posisi');    $this->form_validation->set_rules('nama_anggota','Nama Anggota',    'required');    $this->form_validation->set_rules('email','Email','required');   if($this->form_validation->run() != false){      $config['upload_path'] = './assets/upload/';      $config['allowed_types'] = 'jpg|png|jpeg|pdf';      $config['max_size'] = '2048';      $config['file_name'] = 'gambar'.time();      $this->load->library('upload', $config);      if($this->upload->do_upload('foto')){        $image=$this->upload->data();      $data = array(        'nik' => $nik,        'nama_anggota' => $nama,        'gender' => $gender,        'ttl' => $ttl,        'email' => $email,        'no_telp' => $notelp,        'alamat' => $alamat,        'pendidikan' => $pendidikan,        'status' => $status,        'tinggi_badan' => $tinggi_badan,        'berat_badan' => $berat_badan,        'uk_baju' => $uk_baju,        'uk_celana' => $uk_celana,        'posisi' => $posisi,        'gambar' => $image['file_name']         );我的問題是我無法上傳圖片或 pdf。在我點擊我的視圖提交后，網絡只看到一個空白的白色屏幕。但是，在我添加圖像配置腳本之前，網絡運行良好