玩具店申请

Question

我正在尝试构建在线商店应用程序。我有一个列表视图，其中包含：玩具图片、价格、描述和复选框。当用户单击复选框时，我创建了 CustomObject，当单击按钮 "Buy" 时，我必须将 CustomObject 存储在 mysql 数据库中。主要问题是我不知道如何在列表视图中获取 select 对象以及如何发送到 mysql 数据库。

private RequestQueue requestQueue;
    private StringRequest request;
    private Button btnBuy;
    private ListView lvProducts;
    List<CustomObject>customObjects=new ArrayList<>();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_welcome);

        new JSONTask().execute("http://192.168.1.4:80/Mobilno/Products.php");
       DisplayImageOptions defaultOptions = new DisplayImageOptions.Builder()
        .cacheInMemory(true)
                .cacheOnDisk(true)
        .build();
        ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(getApplicationContext())
        .defaultDisplayImageOptions(defaultOptions)
        .build();
        ImageLoader.getInstance().init(config);
        lvProducts=(ListView)findViewById(R.id.lvProducts);

        btnBuy=(Button)findViewById(R.id.btnBuy);
        btnBuy.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v) {
                request=new StringRequest(Request.Method.POST,"http://192.168.1.4/Mobilno/BuyToy.php",new Response.Listener<String>(){
                    @Override
                    public void onResponse(String response) {
                        try
                        {
                            JSONObject jsonObject=new JSONObject(response);
                            if(jsonObject.names().get(0).equals("success")){
                                Toast.makeText(getApplicationContext(),"success:"+jsonObject.getString("success"),Toast.LENGTH_SHORT).show();

                            }else{  Toast.makeText(getApplicationContext(),"error:"+jsonObject.getString("error"),Toast.LENGTH_SHORT).show();}

                        }

                        catch (JSONException e){e.printStackTrace();}
                    }
                },new Response.ErrorListener(){
                    @Override
                    public void onErrorResponse(VolleyError error) {


                        if (error instanceof NetworkError) {
                            Toast.makeText(getApplicationContext(),"Cannot connect to Internet...Please check your connection!",Toast.LENGTH_SHORT).show();
                        } else if (error instanceof ServerError) {
                            Toast.makeText(getApplicationContext(),"The server could not be found. Please try again after some time!!",Toast.LENGTH_SHORT).show();

                        } else if (error instanceof AuthFailureError) {
                            Toast.makeText(getApplicationContext(),"AuthFailureError",Toast.LENGTH_SHORT).show();
                        } else if (error instanceof ParseError) {
                            Toast.makeText(getApplicationContext(),"Parsing error! Please try again after some time!!",Toast.LENGTH_SHORT).show();

                        } else if (error instanceof NoConnectionError) {
                            Toast.makeText(getApplicationContext(),"NoConnectionError",Toast.LENGTH_SHORT).show();
                        } else if (error instanceof TimeoutError) {
                            Toast.makeText(getApplicationContext(),"Connection TimeOut! Please check your internet connection.",Toast.LENGTH_SHORT).show();

                        }
                    }
                })
                {

                    @Override
                    protected Map<String, String> getParams() throws AuthFailureError {
                        String json_string ="{\"buy\":[";
                        for(int i=0;i<customObjects.size();i++)
                        {
                            JSONObject obj_new = new JSONObject();
                            try {
                                obj_new.put("email", customObjects.get(i));
                                obj_new.put("productID", customObjects.get(i));
                                obj_new.put("price", customObjects.get(i));
                                json_string = json_string + obj_new.toString() + ",";
                            } catch (JSONException e) {
                                e.printStackTrace();
                            }


                        }
                        json_string = json_string.substring(0, json_string.length()-1);
                        json_string += "]}";
                        HashMap<String,String> hashMap=new HashMap<String, String>();
                        hashMap.put("",json_string);
                        return  hashMap;
                    }


                };
                requestQueue.add(request);
            }
        });

    }

-

public class JSONTask extends AsyncTask<String,String,List<Prozivod>>
{

   @Override
    protected List<Product> 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=new StringBuffer();
           String line="";
           while((line=reader.readLine())!=null)
           {
            buffer.append(line);

           }

           String finalJson=buffer.toString();
           JSONArray jsonArray=new JSONArray(finalJson);
           Log.i(finalJson,"json objekat");
           List<Product> listProducts=new ArrayList<>();
           for(int i=0;i<jsonArray.length();i++)
           {
               JSONObject proizvodJson=jsonArray.getJSONObject(i);
               Product p=new Product();
               p.setProizvodID(proizvodJson.getInt("ProductID"));
               p.setCena(proizvodJson.getInt("Price"));
               p.setOpis(proizvodJson.getString("Description"));
               p.setSlika(proizvodJson.getString("Image"));
               listProducts.add(p);
           }
           return  listProducts;
       } catch (MalformedURLException e) {
           e.printStackTrace();
       } catch (IOException e) {
           e.printStackTrace();
       }
       catch (JSONException e) {
           e.printStackTrace();
       }finally {
           if(connection!=null){connection.disconnect();}
       }
       try{if(reader!=null){reader.close();}}
       catch (IOException e) {
           e.printStackTrace();
       }
       return null ;
   }

    @Override
    protected void onPostExecute(final List<Product> result) {
        super.onPostExecute(result);
        ProductAdapter adapter=new ProductAdapter (getApplicationContext(),R.layout.red,result);
        lvProducts.setAdapter(adapter);
    }
}

-

    public  class ProductAdapter extends ArrayAdapter{
    private List<Product>listProducts;
    private int resource;
    private LayoutInflater inflater;
    public ProductAdapter (@NonNull Context context, @LayoutRes int resource, @NonNull List<Product> objects) {
        super(context, resource, objects);
        listProducts=objects;
        this.resource=resource;
        inflater=(LayoutInflater) getSystemService(LAYOUT_INFLATER_SERVICE);
    }

    @NonNull
    @Override
    public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
        ViewHolder holder=null;
        if(convertView==null)
        {
            holder=new ViewHolder();
         convertView=inflater.inflate(resource,null);
            holder.txtImg=(ImageView)convertView.findViewById(R.id.imgProduct);
            holder.txtDescription=(TextView)convertView.findViewById(R.id.txtDescription);
            holder.checkbox=(CheckBox)convertView.findViewById(R.id.checkbox);
            convertView.setTag(holder);
        }
        else {
              holder=(ViewHolder) convertView.getTag();
            }
   ImageLoader.getInstance().displayImage(listProducts.get(position).getImage(),holder.imgProducts);
        convertView.setTag(holder.checkbox);
        holder.checkbox.setOnClickListener(new View.OnClickListener(){
            public  void onClick(View v)
            {
                CheckBox cb=(CheckBox)v;
             Product pro=(Product)cb.getTag();
                CustomObject customObject=new CustomObject();
                customObject.setProductID(pro.getProductID());
                customObject.setPrice(pro.getCena());
                customObject.setEmail(UlogujSe.email);
                customObjects.add(customObject);
            }
        });

        return convertView;
    }
    class ViewHolder
    {
        private ImageView txtImg;
       private TextView txtDescription;
      private   CheckBox checkbox;
    }
}

这是我的 php 脚本，用于测试我从 json 对象的 android 获取数组并且它在邮递员中工作：

<?php
 $DB_HOST = 'localhost';
 $DB_USER = 'root';
 $DB_PASS = '';
 $DB_NAME = "mobilno";

 $mysqli = new mysqli($DB_HOST, $DB_USER, $DB_PASS, $DB_NAME);

 if(mysqli_connect_errno())
{
    echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
else
{
   //echo "Connected to MySQL";
$json = file_get_contents('C:\Users\nadaj\Desktop\streamPhp.txt');
$count=0;
$array = json_decode($json, true);
foreach ($array['buy'] as $item){
     $email= $item['email'];
     $productID= $item['productID'];
     $price=$item['price'];
     $sql = "insert into kupio(email,productID,price) values('$email','$productID','$price')";
     if(mysqli_query($mysqli,$sql))
     {
       $count++;

     }

}
if($count>0){echo $json_odgovor['success']='uspesno!';}
if($count==0){echo $json_odgovor['error']='neuspesno!';}
return $count;
}
 echo json_encode($json_odgovor);
mysqli_close($mysqli);
?>

!

Answer 1

我认为您没有意识到这没有正确发送您的数据。

hashMap.put("",json_string);
return  hashMap;

你需要像 hashMap.put("buy",listOfToys);

这样的东西

此外，volley 默认不发送 json。您需要将 Content-type header 设置为 application/json

如果你想发送 {"buy":[]} json object，我建议你使用 JSONObject Volley 请求并使用JSONObject 参数在 URL 之后，用于 POST json 数据。

注意该方法：您的 PHP 必须 return JSON

例如。 Volley Post method for json object

玩具店申请

application for toys store

android

json

android-volley

listviewitem

android-checkbox