如何使用Codeigniter中的不同按钮在单个表单中上传多个图像和文本文件？

<form method="post" action="upload/process" enctype="multipart/form-data">
  <input type="file" name="image1">
  <input type="file" name="image2">
  <input type="text" name="text1">
  <input type="text" name="text2">
  <button type="submit" name="upload">上传</button>
  <button type="submit" name="save">保存</button>
</form>

class Upload extends CI_Controller {
  public function process() {
    if ($this->input->post('upload')) {
      // 处理上传按钮点击事件
      $config['upload_path'] = './uploads/';
      $config['allowed_types'] = 'gif|jpg|png';
      $this->load->library('upload', $config);

      if ($this->upload->do_upload('image1')) {
        $data = $this->upload->data();
        // 处理上传的图像1
      }

      if ($this->upload->do_upload('image2')) {
        $data = $this->upload->data();
        // 处理上传的图像2
      }
    } elseif ($this->input->post('save')) {
      // 处理保存按钮点击事件
      $text1 = $this->input->post('text1');
      $text2 = $this->input->post('text2');
      // 处理文本输入值
    }
  }
}