symfony一个方法，我写进路由能正常访问，但是通过命令行执行就报错，怎么解决？

[weixin_38051598]

我写了一个myComand类： <?php //src/ChannelBundle/Command/MyCommand.php namespace ChannelBundle\Command; use Symfony\Bundle\FrameworkBundle\Command\ContainerAwareCommand; use Symfony\Component\Console\Output\OutputInterface; use Symfony\Component\Console\Input\InputInterface; use Symfony\Component\Console\Input\InputArgument; use Symfony\Component\Console\Input\InputOption; use ChannelBundle\Controller\CmdController; class MyCommand extends ContainerAwareCommand { protected function configure() { $this->setName('action:run') ->setDescription('Run an action.') ->addArgument('name', InputArgument::OPTIONAL, 'Chouse an action to run.') ->addOption('show', null, InputOption::VALUE_NONE, 'Show result.'); } protected function execute(InputInterface $input, OutputInterface $output) { $action = new CmdController(); $name = $input->getArgument('name'); if ($name == 'action1'){ $text = $action->insertData(); }elseif($name == 'action2') { $text = $action->deleteData(); }elseif($name == 'action3') { $text = $action->updateData(); }elseif($name == 'action4') { $text = $action->seleteData(); }else { $text = 'Error[101]:Cmd error.'; } if (!$input->getOption('show')){ $text = NULL; } $output->writeln($text); } } 可以看出，我通过这个类，创建命令行，执行另一个类：CmdController中的方法：insertData public function insertData() { if($this->get('database_connection')) $str = "Action4 has been executed."; else $str = "Errors[001]:Syntax error!"; return $str; } 但是 $this->get('database_connection') 一直报错：   [Symfony\Component\Debug\Exception\FatalThrowableError]   Call to a member function get() on null 通过路由可以执行这个方法的，为什么不能通过命令行来执行呢？