Question

我有两个凌空请求值从第二个请求返回第一个请求，其中值用于制作循环视图。返回值，我将参数作为字段，但其值不会从0更改为默认值。

我的第一次截击请求：

private void callplcaedetails(String id) {
        RequestQueue queue = Volley.newRequestQueue(this);
        System.out.println("id" + id);
        String url = "https://maps.googleapis.com/maps/api/place/details/json?placeid=" + id + "&key=AIzaSyDi9vrZ0F3TX***********Q";
// Request a string response from the provided URL.
        StringRequest stringRequest = new StringRequest(com.android.volley.Request.Method.GET, url,
                new Response.Listener<String>() {
                    @Override
                    public void onResponse(String response) {
                        // Display the first 500 characters of the response string.
                        //  Log.i("Response is: ", response);

                        JSONObject m = null;

                        try {
                            m = new JSONObject(response);


                            reader1 = m.getJSONObject("result");
                            String nameofplace = reader1.getString("name");
                            JSONObject geometry = reader1.getJSONObject("geometry");
                            JSONObject location = geometry.getJSONObject("location");
                            String lat = location.getString("lat");
                            String lng = location.getString("lng");
                            Log.i("lat" + lat, "lng" + lng);
                            Addressname = reader1.getString("formatted_address");
                            float x1=getdistance(lat,lng);
                            Log.i("disatancccccccc",x1+"");
                            placelist.add(new Place(nameofplace, Addressname, x1));
                            mAdapter.notifyDataSetChanged();
                        } catch (JSONException e) {
                            e.printStackTrace();
                        }
                    }
                }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                Log.i("Not worked", "That didn't work!");
            }
        });
// Add the request to the RequestQueue.
        queue.add(stringRequest);
    }

我的第二次截击请求：

    private Float getdistance(String lat, String lng) {
        RequestQueue queue = Volley.newRequestQueue(this);

        String url = "https://maps.googleapis.com/maps/api/distancematrix/json?units=metric&origins="+latitude+","+longitude+"&destinations="+lat+","+lng+"&key=AIzaSyDi9vrZ0F3T******Y3GlQ";
// Request a string response from the provided URL.
        StringRequest stringRequest = new StringRequest(com.android.volley.Request.Method.GET, url,
                new Response.Listener<String>() {


                    @Override
                    public void onResponse(String response) {
                        // Display the first 500 characters of the response string.
                         Log.i("Response is: ", response);

                        JSONObject m = null;

                        try {
                            m = new JSONObject(response);


                           JSONArray reader1 = m.getJSONArray("rows");
                            JSONObject e =  reader1.getJSONObject(0);
                            JSONArray f = e.getJSONArray("elements");
                            JSONObject g =f.getJSONObject(0);
                           JSONObject h= g.getJSONObject("distance");
                            String dist = h.getString("value");


                            x = Float.parseFloat(dist);
                            Log.i("distance",x+"");
                        } catch (JSONException e) {
                            e.printStackTrace();
                        }
                    }
                }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                Log.i("Not worked", "That didn't work!");
            }
        });
// Add the request to the RequestQueue.
        queue.add(stringRequest);
        System.out.println("Distance Value"+x);
        return x;
    }

日志响应

 I/disatancccccccc: 0.0
 I/lat22.9575252: lng76.04197789999999
 I/System.out: dkkvnjnvfnvjnvdfjvndfvjn0.0
 I/disatancccccccc: 0.0
 I/Response is:: "Response works right"  
 I/distance: 3595.0

距离正确，这有什么问题，哪种方式更好。

Answer 1

注意： i made the parameter as final, but its value does not change from 0 which was default.在宣布variable final时，请在您的问题中提及，这意味着在将其声明为cant change后，您final了其值你可以从最终的名字中理解。

<强>解决方案：

您必须将变量声明为class level，而dont将变量声明为final并将值赋给它然后再使用它。

public class AboutUsActivity extends Activity {

    int x=0;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);

    }

     //your response callback value
     void XYZResponce(int result){
        x = result;
       }
 }

从截击请求返回时参数的值不会改变

1 个答案: