使用SearchView搜索ListView（关于JSON）

我有困难时期，我在编程方面是新的，我已经搜索关于在ListView（用JSON检索数据的地方）搜索教程，但是当我尝试应用它我的应用程序不起作用。没有错误，我可以输入SearchView，但ListView不会更新或响应我在里面输入的内容。使用SearchView搜索ListView（关于JSON）

我MainActivity.java类：

package rjj.tutorial_jsonandlistview; 

import android.content.Intent; 
import android.os.AsyncTask; 
import android.support.v7.app.AppCompatActivity; 
import android.os.Bundle; 
import android.view.View; 
import android.widget.TextView; 
import android.widget.Toast; 

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; 


public class MainActivity extends AppCompatActivity { 

    String Json_STRING; 


    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 
     new BackgroundTask().execute(); 
     //new line 


    } 


    class BackgroundTask extends AsyncTask<Void, Void, String> { 

     String json_url; 
     String JSON_STRING; 

     @Override 
     protected void onPreExecute() { 

      json_url = "http://10.0.2.2/rizal22.php"; 
     } 

     @Override 
     protected String doInBackground(Void... params) { 
      try { 
       URL url = new URL(json_url); 
       HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection(); 
       InputStream inputStream = httpURLConnection.getInputStream(); 
       BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream)); 
       StringBuilder stringBuilder = new StringBuilder(); 
       while ((JSON_STRING = bufferedReader.readLine()) != null) { 

        stringBuilder.append(JSON_STRING + "\n"); 
       } 

       bufferedReader.close(); 
       inputStream.close(); 
       httpURLConnection.disconnect(); 
       return stringBuilder.toString().trim(); 
      } catch (MalformedURLException e) { 
       e.printStackTrace(); 
      } catch (IOException e) { 
       e.printStackTrace(); 
      } 

      return null; 
     } 

     @Override 
     protected void onProgressUpdate(Void... values) { 
      super.onProgressUpdate(values); 
     } 

     @Override 
     protected void onPostExecute(String result) { 
      TextView textView = (TextView)findViewById(R.id.textView2); 
      textView.setText(result); 
      Json_STRING = result; 
     } 

    } 
    //List view time! 
    public void parseJSON(View view) { 
     if(Json_STRING == null){ 
      Toast.makeText(getApplicationContext(), "First Get JSON", Toast.LENGTH_SHORT).show(); 
     }else{ 
      Intent intent = new Intent(this, DisplayListView.class); 
      intent.putExtra("json_data", Json_STRING); 
      startActivity(intent); 
     } 

    } 

}

我DisplayListView类，在这里我将搜索使用搜索查看。

package rjj.tutorial_jsonandlistview; 

import android.content.Intent; 
import android.support.v7.app.AppCompatActivity; 
import android.os.Bundle; 


import android.view.View; 
import android.widget.AdapterView; 
import android.widget.ListView; 
import android.widget.SearchView; 
import android.widget.TextView; 

import org.json.JSONArray; 
import org.json.JSONException; 
import org.json.JSONObject; 



public class DisplayListView extends AppCompatActivity { 

    String json_string; 
    JSONObject jsonObject; 
    JSONArray jsonArray; 
    ContactAdapter contactAdapter; 
    ListView listView; 
    SearchView sv; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.display_listview_layout); 
     listView = (ListView)findViewById(R.id.listview); 

     contactAdapter = new ContactAdapter(this,R.layout.row_layout); 
     listView.setAdapter(contactAdapter); 

     json_string = getIntent().getExtras().getString("json_data"); 
     listView.setOnItemClickListener(new AdapterView.OnItemClickListener() { 
      @Override 
      public void onItemClick(AdapterView<?> parent, View view, int position, long id) { 



       TextView textView = (TextView) view.findViewById(R.id.tx_id); 

       String text = textView.getText().toString(); 
       Intent intent = new Intent(DisplayListView.this, Update.class); 
       intent.putExtra("id", text); 
       //new line 
       intent.putExtra("json_data", json_string); 
       startActivity(intent); 
      } 

     }); 
     //Searchview 
     sv = (SearchView)findViewById(R.id.search); 

     sv.setOnQueryTextListener(new SearchView.OnQueryTextListener() { 
      @Override 
      public boolean onQueryTextSubmit(String query) { 
       return false; 
      } 

      @Override 
      public boolean onQueryTextChange(String newText) { 
       contactAdapter.getFilter(

       ).filter(newText); 
       listView.setFilterText(newText); 
       return true; 
      } 
     }); 
     //End of Searchview 

     try { 
      jsonObject = new JSONObject(json_string); 
      jsonArray = jsonObject.getJSONArray("server_response"); 
      int count = 0; 
      String id ,firstname , surname, age , username, password; 


      while(count<jsonArray.length()){ 
       JSONObject JO = jsonArray.getJSONObject(count); 
       id = JO.getString("id"); 
       firstname = JO.getString("PLATE_NUM"); 
       surname = JO.getString("PUV_TYPE"); 
       Contacts contact = new Contacts(id, firstname, surname); 
       contactAdapter.add(contact); 


       count++; 

      } 
     } catch (JSONException e) { 
      e.printStackTrace(); 
     } 

    } 

}

这是我Contacts.java类：

package rjj.tutorial_jsonandlistview; 

/** 
* Created by Julian on 7/20/2017. 
*/ 

public class Contacts { 

    private String id,firstname,surname,age,username,password; 

    public Contacts(String id, String firstname, String surname){ 


      this.setId(id); 
      this.setFirstname(firstname); 
      this.setSurname(surname); 





    } 
    public String getId() { 
     return id; 
    } 

    public void setId(String id) { 
     this.id = id; 
    } 

    public String getFirstname() { 
     return firstname; 
    } 

    public void setFirstname(String firstname) { 
     this.firstname = firstname; 
    } 

    public String getSurname() { 
     return surname; 
    } 

    public void setSurname(String surname) { 
     this.surname = surname; 
    } 


}

这是我ContactAdapater.java类：

package rjj.tutorial_jsonandlistview; 

import android.content.Context; 
import android.support.annotation.LayoutRes; 
import android.support.annotation.NonNull; 
import android.support.annotation.Nullable; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.ArrayAdapter; 
import android.widget.TextView; 

import java.util.ArrayList; 
import java.util.List; 

/** 
* Created by Julian on 7/20/2017. 
*/ 

public class ContactAdapter extends ArrayAdapter { 
    List list = new ArrayList(); 

    public ContactAdapter(@NonNull Context context, @LayoutRes int resource) { 
     super(context, resource); 


    } 


    public void add(Contacts object) { 
     super.add(object); 
     list.add(object); 
    } 

    @Override 
    public int getCount() { 
     return list.size(); 
    } 

    @Nullable 
    @Override 
    public Object getItem(int position) { 
     return list.get(position); 
    } 

    @NonNull 
    @Override 
    public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) { 

     View row; 
     row = convertView; 
     ContactHolder contactHolder; 
     if(row == null){ 
      LayoutInflater layoutInflater = (LayoutInflater) this.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
      row = layoutInflater.inflate(R.layout.row_layout,parent,false); 
      contactHolder = new ContactHolder(); 
      contactHolder.tx_id = (TextView)row.findViewById(R.id.tx_id); 
      contactHolder.tx_firstname = (TextView)row.findViewById(R.id.tx_firstname); 
      contactHolder.tx_surname = (TextView)row.findViewById(R.id.tx_surname); 

      row.setTag(contactHolder); 

     } else{ 
      contactHolder = (ContactHolder)row.getTag(); 
     } 
     Contacts contacts = (Contacts)this.getItem(position); 
     contactHolder.tx_id.setText(contacts.getId()); 
     contactHolder.tx_firstname.setText(contacts.getFirstname()); 
     contactHolder.tx_surname.setText(contacts.getSurname()); 

     return row; 
    } 

    static class ContactHolder{ 
     TextView tx_id, tx_firstname, tx_surname; 
    } 

}

我的PHP文件：

<?php 
$host='localhost'; 
$user='root'; 
$password=''; 
$db='employee101'; 
//Old id $_id = $_POST['id']; 
$sql = "select * from employee_data;"; 
//Old line $sql = "select * from employee_data where id = $_id;"; 

$con = mysqli_connect($host,$user,$password,$db); 

$result = mysqli_query($con, $sql); 

$response = array(); 

while($row = mysqli_fetch_array($result)){ 

    array_push($response,array("id"=>$row[0],"PLATE_NUM"=>$row[1],"PUV_TYPE"=>$row[2])); 

} 

echo json_encode(array("server_response"=>$response)); 

mysqli_close($con); 




?>

来源

2017-07-29 YaZao RuZakiaga

什么是来自urlconnection的http状态/响应代码？假设device和localhost都在同一个网络中 – user1140237

尝试在你的custome arrayadapter类中添加FIlterable。检查[this]（https://stackoverflow.com/a/19301216/5343320）以供参考。 – huk

@ user1140237 listview显示正确的JSON数组。 SearchView只是不响应用户输入的内容，它只是保持不变。对不起，我们有一个因特网问题，这就是为什么我现在只是回应 –

希望这方法有帮助。

声明在上面这个变量在适配器

public ArrayList<Contacts> searchList=new ArrayList<>();

然后这个方法在适配器

public void filter(String charText) { 
    charText = charText.toLowerCase(Locale.getDefault()); 
    list.clear(); 
    if (charText.length() == 0) { 
     list.addAll(searchList); 
    } 
    else 
    { 
     for (Contacts wp : searchList) 
     { 
      if (wp.getTitle().toLowerCase(Locale.getDefault()).contains(charText)) 
      { 
       list.add(wp); 
      } 
     } 
    } 
    notifyDataSetChanged(); 
}

，最后调用这个方法在活动这样

mAdapter.filter(text);

和地点上述方法请拨打

@Override 
     public boolean onQueryTextChange(String newText) { 
      contactAdapter.filter(newText); 
      return true; 
     }

来源

2017-07-29 09:58:10

ContactAdapter.java类里面的所有内容对吗？除了mAdapater.filter（文本） –

我不明白你能不能请你解释一下 –

是的，你知道的没错 – 2017-07-29 12:10:42

使用SearchView搜索ListView（关于JSON）

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