从URL加载JSON数据时如何显示加载（圆圈）

Question

I am new to Android Studio and I am trying to make my simple app get JSON data from an URL using Volley.
Everything is fine, but I want to I want to display a loading circle when it gets the JSON data.

my code if any one can help me

package imo.meteoiraq;

import android.os.Handler;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;
import android.widget.Toast;

import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonObjectRequest;
import com.android.volley.toolbox.Volley;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import org.json.JSONException;
import org.json.JSONObject;

import java.security.Timestamp;

public class MainActivity extends AppCompatActivity {
    RequestQueue rq;
    TextView timeDesc, tempDesc, windspeedDesc, windguestDesc, humdityDesc;
    int ages;
    int temp;
    int windspeed;
    int windguest;
    int humdity;
    long timeupdate;

    String url = "stationlookup?station=I1410&units=metric&v=2.0&format=json";

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        rq = Volley.newRequestQueue(this);

        timeDesc = (TextView) findViewById(R.id.timeupdateDesc);
        tempDesc = (TextView) findViewById(R.id.tempid);
        windspeedDesc = (TextView) findViewById(R.id.windid);
        windguestDesc = (TextView) findViewById(R.id.windgustid);
        humdityDesc = (TextView) findViewById(R.id.humdid);

        sendjsonrequest();
    }

    public void sendjsonrequest() {
        JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(Request.Method.GET, url, null, new Response.Listener<JSONObject>() {
            @Override
            public void onResponse(JSONObject response) {
                try {

                    JSONObject stationsJO = response.getJSONObject("stations");
                    JSONObject I1410JO = stationsJO.getJSONObject("I1410");
                    temp = I1410JO.getInt("temperature");
                    windspeed = I1410JO.getInt("wind_speed");
                    windguest = I1410JO.getInt("wind_gust_speed");
                    humdity = I1410JO.getInt("humidity");
                    timeupdate = I1410JO.getLong("updated") * 1000L;

                    tempDesc.setText(Integer.toString(temp));
                    windspeedDesc.setText(Integer.toString(windspeed));
                    windguestDesc.setText(Integer.toString(windguest));
                    humdityDesc.setText(Integer.toString(humdity));
                    timeDesc.setText(getDate(timeupdate));
                } catch (JSONException e) {
                    e.printStackTrace();
                }
            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {

            }
        });
        rq.add(jsonObjectRequest);
        final Handler handler = new Handler();
        final Runnable runnable = new Runnable() {
            @Override
            public void run() {
                sendjsonrequest();
                handler.postDelayed(this, 6000);//60 second delay
            }
        };
        handler.postDelayed(runnable, 1000);
    }

    private String getDate(long timeStamp) {
        try {
            DateFormat sdf = new SimpleDateFormat("MM/dd/yyyy hh:mm:ss");
            Date netDate = (new Date(timeStamp));
            return sdf.format(netDate);
        } catch (Exception ex) {
            return "xx";
        }
    }


    }

Answer 1

All you need is a ProgressBar in your layout. You can set the visibility as invisible at the beginning. Then when you start parsing set the visibility to visible and when you finish to invisible again. I think this is the easiest way to do it.

Answer 2

Try this:

package imo.meteoiraq;

import android.os.Handler;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;
import android.widget.Toast;

import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonObjectRequest;
import com.android.volley.toolbox.Volley;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import org.json.JSONException;
import org.json.JSONObject;

import java.security.Timestamp;

public class MainActivity extends AppCompatActivity {
    RequestQueue rq;
    TextView timeDesc, tempDesc, windspeedDesc, windguestDesc, humdityDesc;
    int ages;
    int temp;
    int windspeed;
    int windguest;
    int humdity;
    long timeupdate;

    String url = "stationlookup?station=I1410&units=metric&v=2.0&format=json";

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        rq = Volley.newRequestQueue(this);

        timeDesc = (TextView) findViewById(R.id.timeupdateDesc);
        tempDesc = (TextView) findViewById(R.id.tempid);
        windspeedDesc = (TextView) findViewById(R.id.windid);
        windguestDesc = (TextView) findViewById(R.id.windgustid);
        humdityDesc = (TextView) findViewById(R.id.humdid);

        sendjsonrequest();
    }

    public void sendjsonrequest() {
 final ProgressDialog dialog = ProgressDialog.show(this, null, "Please Wait");
        JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(Request.Method.GET, url, null, new Response.Listener<JSONObject>() {
            @Override
            public void onResponse(JSONObject response) {
 dialog.dismiss();
                try {

                    JSONObject stationsJO = response.getJSONObject("stations");
                    JSONObject I1410JO = stationsJO.getJSONObject("I1410");
                    temp = I1410JO.getInt("temperature");
                    windspeed = I1410JO.getInt("wind_speed");
                    windguest = I1410JO.getInt("wind_gust_speed");
                    humdity = I1410JO.getInt("humidity");
                    timeupdate = I1410JO.getLong("updated") * 1000L;

                    tempDesc.setText(Integer.toString(temp));
                    windspeedDesc.setText(Integer.toString(windspeed));
                    windguestDesc.setText(Integer.toString(windguest));
                    humdityDesc.setText(Integer.toString(humdity));
                    timeDesc.setText(getDate(timeupdate));
                } catch (JSONException e) {
                    e.printStackTrace();
                }
            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
 dialog.dismiss();
            }
        });
        rq.add(jsonObjectRequest);
        final Handler handler = new Handler();
        final Runnable runnable = new Runnable() {
            @Override
            public void run() {
                sendjsonrequest();
                handler.postDelayed(this, 6000);//60 second delay
            }
        };
        handler.postDelayed(runnable, 1000);
    }

    private String getDate(long timeStamp) {
        try {
            DateFormat sdf = new SimpleDateFormat("MM/dd/yyyy hh:mm:ss");
            Date netDate = (new Date(timeStamp));
            return sdf.format(netDate);
        } catch (Exception ex) {
            return "xx";
        }
    }


    }