小编San*_*tha的帖子

这是我从互联网上获得的代码,我需要它用于我自己的应用程序.我正在尝试使用该示例制作应用程序.不同之处在于我为此命名了一个单独的类JSONTask.我的getApplicationContex()功能出错了.请帮我解决一下这个.

import android.os.AsyncTask;
import android.widget.ListView;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import navdrawerexample1.models.MovieModel;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;

public class JSONTask extends AsyncTask<String,String,List<MovieModel>>
{
private ListView lvMovies;
@Override
protected List<MovieModel> doInBackground(String... params) {
    HttpURLConnection connection = null;
    BufferedReader reader = null;
    try {
        URL url= new URL(params[0]);
        connection = (HttpURLConnection) url.openConnection();
        connection.connect();


        InputStream stream = connection.getInputStream();
        reader = new BufferedReader(new InputStreamReader(stream));
        StringBuffer buffer …

我的代码工作正常,但是当我点击提交按钮时,它会显示两次凌空基本网络执行请求,并且我的数据库表会更新两次.

这是我的MainActivity代码:

import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import com.android.volley.AuthFailureError;
import com.android.volley.NetworkError;
import com.android.volley.NetworkResponse;
import com.android.volley.NoConnectionError;
import com.android.volley.ParseError;
import com.android.volley.Request;
import com.android.volley.Response;
import com.android.volley.ServerError;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;

import java.util.HashMap;
import java.util.Map;

public class LoginActivity extends AppCompatActivity  {
    EditText etUsername, etPassword;
    Button bLogin;
    final String TAG= this.getClass().getSimpleName();
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                WindowManager.LayoutParams.FLAG_FULLSCREEN);
        setContentView(R.layout.activity_login);
        etUsername = (EditText) findViewById(R.id.etUserName);
        etPassword = (EditText) …