如何在 recyclerview 上解析这个 json 对象？ [关闭]

Question

我想在 recyclerview 中显示这个 json。我该怎么做？ 我只想列出“user”和“exchangeName”。

我的 Json;

{ “事件”：{ “101”：{ “id”：“0001”， “类型”：“交换”， “用户”：“BTUser01”， "exchangeName": "BTCTurk", “交易”：{ “发送”：“249”， “得到”：“24.1” }, “证书”： [ “BTUser01证书” ] }, “102”：{ “id”：“0002”， “类型”：“交换”， “用户”：“BTUser02”， "exchangeName": "Koinim", “交易”：{ “发送”：“300”， “得到”：“641” }, “证书”： [ “BTUser02证书” ] }, “103”：{ “id”：“0003”， “类型”：“exchange2”， “用户”：“BTUser03”， "exchangeName": "Koineks", “交易”：{ “发送”：“823”， “得到”：“751” }, “证书”： [ “BTUser03证书” ] }, “104”：{ “id”：“0004”， “类型”：“exchange3”， “用户”：“BTUser04”， "exchangeName": "Paribu", “交易”：{ “发送”：“543”， “得到”：“3.1” }, “证书”： [ “BTUser04证书” ] } } }

主活动；

public class MainActivity extends AppCompatActivity {

    TextView ev, ev2;

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

        ev = (TextView) findViewById(R.id.ev);
        ev2 = (TextView) findViewById(R.id.ev2);

        Retrofit retrofit = new Retrofit.Builder().baseUrl("MYAPİ_ADRESS_LINK").addConverterFactory(GsonConverterFactory.create()).build();
        Service service = retrofit.create(Service.class);

        Call<ResponseBody> call = service.getData();
        call.enqueue(new Callback<ResponseBody>() {
            @Override
            public void onResponse(@NonNull Call<ResponseBody> call, @NonNull Response<ResponseBody> response) {
                if (response.isSuccessful()) {
                    String res = null;
                    if (response.body() != null) {
                        try {
                            res = response.body().string();
                            parse(res);
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                }
            }

            @Override
            public void onFailure(@NonNull Call<ResponseBody> call, @NonNull Throwable t) {
                int a = 0;
            }
        });

    }

    Model parse(String str) {
        Model model = new Model();
        try {
            String source = str.replace("\n", "").replace("\t", "").replace("\r", "");
            String s = new Gson().toJson(source);
            s = s.replace("\\","");
            s = s.substring(1,s.length()-1);
            JSONObject object = new JSONObject(s).getJSONObject("events");
            Iterator<String> iter = object.keys();
            while (iter.hasNext()) {
                String key = iter.next();
                try {
                    JSONObject value = new JSONObject(String.valueOf(object.get(key)));
                    model.setExternalId(Integer.parseInt(key));
                    model.setUser(value.getString("user"));
                    model.setSend(value.getString("send"));

                    ev.setText(model.user);
                    ev2.setText(model.send);


                    return model;


                } catch (JSONException e) {
                    // Something went wrong!
                }
            }


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

        return model;
    }
}

我的模型；

public class Model {

    int externalId;
    int id;
    String type;
    String user;
    String exchangeName;
    Transactions transactions;






    List<certificate> certificateList;

    public int getExternalId() {
        return externalId;
    }

    public void setExternalId(int externalId) {
        this.externalId = externalId;
    }

    public int getId() {
        return id;
    }

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

    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    }

    public String getUser() {
        return user;
    }

    public void setUser(String user) {
        this.user = user;
    }

    public String getExchangeName() {
        return exchangeName;
    }

    public void setExchangeName(String exchangeName) {
        this.exchangeName = exchangeName;
    }

    public Transactions getTransactions() {
        return transactions;
    }

    public void setTransactions(Transactions transactions) {
        this.transactions = transactions;
    }

    public List<certificate> getCertificateList() {
        return certificateList;
    }

    public void setCertificateList(List<certificate> certificateList) {
        this.certificateList = certificateList;
    }

    class Transactions{
        String send;

        String get;

        public String getSend() {
            return send;
        }

        public void setSend(String send) {
            this.send = send;
        }

        public String getGet() {
            return get;
        }

        public void setGet(String get) {
            this.get = get;
        }
    }

    class certificate{
        String name;

        public String getName() {
            return name;
        }

        public void setName(String name) {
            this.name = name;
        }
    }

}

Answer 1

首先，您可以在数百个可用的教程和指南中轻松找到这个答案。

要实现这一点，您需要为适配器项创建一个自定义适配器和一个自定义视图。

作为这个答案的序言。我不确定您是否想在RecyclerView 中显示多个Model 项目或其他一些数据。此示例假定您使用 List<Model>，但是，可以轻松更改以使其与另一个对象列表一起使用。

适配器外观示例

public class MyAdapter extends RecyclerView.Adapter
{
    private Context _context;

    private List<Model> _items;

    public void setItems(List<Model> items)
    {
        this._items = items;
        notifyDataSetChanged();
    }

    @NonNull
    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType)
    {
        _context = parent.getContext();
        return new MyAdapter.ItemViewHolder(parent);
    }

    @Override
    public void onBindViewHolder(@NonNull final RecyclerView.ViewHolder holder, int position)
    {
        final MyAdapter.ItemViewHolder viewHolder = (MyAdapter.ItemViewHolder) holder;
        final Model item = _items.get(position);

        viewHolder._user.setText(item.user);
        viewHolder._exchangeName.setText(item.exchangeName);
    }

    @Override
    public int getItemCount()
    {
        return _items != null ? _items.size() : 0;
    }

    private static class ItemViewHolder extends RecyclerView.ViewHolder
    {
        private TextView _user;
        private TextView _exchangeName;

        private ItemViewHolder(ViewGroup parent)
        {
            super(LayoutInflater.from(parent.getContext()).inflate(R.layout.adapter_view, parent, false));
            this._user = itemView.findViewById(R.id.user);
            this._exchangeName = itemView.findViewById(R.id.exchange_name);
        }
    }
}

R.layout.adapter_view

这需要是至少包含来自上述MyAdapter 的两个TextView 视图引用的视图。简单例子：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:background="@drawable/content_container"
    android:orientation="vertical"
    android:animateLayoutChanges="true"
    android:padding="@dimen/padding_view_large"
    android:layout_marginBottom="@dimen/padding_view_small">

    <TextView
        android:id="@+id/user"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/placeholder"
        android:textColor="@color/black"
        android:textSize="@dimen/text_size_medium"
        android:layout_marginTop="@dimen/padding_view_small"/>

    <TextView
        android:id="@+id/exchange_name"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/placeholder"
        android:textColor="@color/black"
        android:textSize="@dimen/text_size_medium"
        android:layout_marginTop="@dimen/padding_view_small"/>

</LinearLayout>

绑定适配器

//First we set up the adapter and add our List<Model> object.
MyAdapter adapter = new MyAdapter();
adapter.setItems(... List<Model> items);

//Set up our RecyclerView and set the adapter.
final RecyclerView recyclerView = rootView.findViewById(R.id.model_list);
recyclerView.setLayoutManager(new LinearLayoutManager(_context));
recyclerView.setAdapter(adapter);
recyclerView.setHasFixedSize(true);

Answer 2

您需要先了解（然后创建）以下内容

1. RecyclerView 适配器

2. RecyclerView ViewHolder

阅读完这两件事后，解决方案就会很清楚了。为了给您指明正确的方向，您必须创建一个自定义适配器，您将使用它来填充您的自定义视图。希望这可以帮助您继续前进。随时询问您是否需要更多帮助。