java Android活动因在碎片上发送数据而无限重新打开

Question

我试图基于this reference将数据从片段发送到活动。因此，我实现了以下代码，将数据发送到活动：

在地图片段中。java

    @Override //::LocationListener (Interface)
    public void onLocationChanged(Location location)
    {

        mCurrentLocation = location;
        CameraUpdate cameraUpdate = CameraUpdateFactory.newLatLngZoom(new LatLng(mCurrentLocation.getLatitude(), mCurrentLocation.getLongitude()), 15);
        googleMap.animateCamera(cameraUpdate);

        double x = location.getLatitude();
        double y = location.getLongitude();

        String request = url+x+","+y;
        Log.d("log1=",request);
        StringRequest stringRequest = new StringRequest(Request.Method.GET, request,
                new Response.Listener<String>() {
                    @Override
                    public void onResponse(String _response) {

                        Log.d("log_res=",_response);
                        sendData(_response);
                    }
                }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {

                // Error handling
                Log.d("log_err=", error.toString());

            }
        });

        Volley.newRequestQueue(activity.getBaseContext()).add(stringRequest);

        Toast.makeText(activity, "Update location user ==>" + mCurrentLocation.getLatitude() + "," + mCurrentLocation.getLongitude(), Toast.LENGTH_SHORT).show();
        Log.d(TAG, "Current Location :" + mCurrentLocation.getLatitude() + "," + mCurrentLocation.getLongitude());
    }

    //===send data to activity===

    private void sendData(String _Output)
    {
        try {

            Log.d("output",_output);

            Intent intent = new Intent(getActivity().getBaseContext(), MainActivity.class);
            intent.putExtra("message", latd.toString() + "," + lang.toString());
            Log.d("msg=", latd.toString() + "," + lang.toString());
            activity.startActivity(intent);

        }
        catch (Exception jsoe){

            Log.e("err=>", jsoe.toString());
        }
    }

    //===interface===
    OnFragmentChangedListener mCallback;

    // Container Activity must implement this interface
    public interface OnFragmentChangedListener {
      public void onMapChanged(String name);
    }


    @Override //::BaseFragment (Class)
    public void onAttach(Activity _activity) {
      super.onAttach(_activity);
      this.activity = _activity;

      try {
         mCallback = (OnFragmentChangedListener) activity;
      } catch (ClassCastException e) {
          throw new ClassCastException(activity.toString()
                  + " must implement OnHeadlineSelectedListener");
      }

    }

在维护中。java

 @Override
    public void onMapChanged(String name)  {
            Log.d("act=>", name);
            Intent intent = getIntent();
            String message = intent.getStringExtra("message");

    }

关于上述代码的一点解释：在片段中，每次GPS检测到新的坐标，我捕获纬度和经度，然后尝试发送到活动

然而，每次我打电话给activity.startActivity(intent)；然后，该应用程序无限制地重新打开新活动

Answer 1

在清单中将午餐模式添加到您的活动中。xml

<activity
    android:name=".MainActivity"
    android:launchMode="singleTask">
</activity>