Android 在片段中使用TelephonyManager？

我想在设备调用时启动和停止服务，所以我使用TelephonyManager和我的类扩展标记。我试过这个密码

 TelephonyManager tm = (TelephonyManager)getActivity().getSystemService(Context.TELEPHONY_SERVICE);
        tm.listen(mPhoneListener, PhoneStateListener.LISTEN_CALL_STATE);


    private PhoneStateListener mPhoneListener = new PhoneStateListener() {
    public void onCallStateChanged(int state, String incomingNumber) {

            switch (state) {
            case TelephonyManager.CALL_STATE_RINGING:
                getActivity().stopService(new Intent(getActivity(),LockScreenService.class));

                break;

            case TelephonyManager.CALL_STATE_OFFHOOK:
                getActivity().stopService(new Intent(getActivity(),LockScreenService.class));
                break;

            case TelephonyManager.CALL_STATE_IDLE:
                getActivity().startService(new Intent(getActivity(),LockScreenService.class));

                break;

            }
        } 
    } 
;

但它不起作用。请给我一些建议。非常感谢

请尝试以下代码：

 telephonyManager  =  ( TelephonyManager )getActivity.getSystemService( Context.TELEPHONY_SERVICE );
 imeistring = telephonyManager.getDeviceId(); 

---

您面临的问题是什么？我的服务被强制关闭。请附加日志以了解根本原因