android - android知道邮件何时发送并在发送后执行操作

Question

我从我的 android 应用程序发送电子邮件

                  Intent email = new Intent(Intent.ACTION_SEND);
                  email.putExtra(Intent.EXTRA_EMAIL, new String[]{ to});
                                  email.putExtra(Intent.EXTRA_SUBJECT, subject);
                  email.putExtra(Intent.EXTRA_TEXT, message);

                  //attachment
                  Uri uri = Uri.fromFile(new File(Environment.getExternalStorageDirectory(), "generato.pdf"));
                  email.putExtra(Intent.EXTRA_STREAM, uri);

                  //need this to prompts email client only
                  email.setType("message/rfc822");

                  startActivity(Intent.createChooser(email, "Choose an Email client :"));

我如何知道发送邮件后“composer”窗口何时被关闭，以便我可以开始另一个操作？

谢谢！