firebaserecycleradapter() 不能应用于 FirebaseRecyclerAdapter

Question

谁能告诉我该行的错误是什么。

这是显示的错误消息。

package com.example.souravkumar.sqaurewallpapers;

import android.os.Bundle;
import android.os.PersistableBundle;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;

import com.firebase.ui.database.FirebaseRecyclerAdapter;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.squareup.picasso.Picasso;

/**
 * Created by Sourav Kumar on 11/3/2017.
 */

public class popular extends AppCompatActivity {

    private RecyclerView recyclerView;
    private DatabaseReference myRef;
    @Override
    public void onCreate(@Nullable Bundle savedInstanceState, @Nullable PersistableBundle persistentState) {
        super.onCreate(savedInstanceState, persistentState);
        recyclerView = (RecyclerView) findViewById(R.id.recyclerView);
        recyclerView.setHasFixedSize(true);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));
        myRef = FirebaseDatabase.getInstance().getReference();
        FirebaseRecyclerAdapter<image_details, BlogViewHolder> adapter = new FirebaseRecyclerAdapter<image_details, BlogViewHolder>(
                image_details.class,
                R.layout.individual_row,

                myRef) {
            @Override
            protected void onBindViewHolder(BlogViewHolder holder, int position, image_details model) {
                holder.setDate(model.getDate());
                holder.setUrl(model.getUrl());
            }

            @Override
            public BlogViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
                return null;
            }
        };

        recyclerView.setAdapter(adapter);

    }

    public static  class BlogViewHolder extends RecyclerView.ViewHolder {
        TextView textView;
        ImageView imageView;
        public BlogViewHolder(View itemView) {
            super(itemView);
            textView = (TextView)itemView.findViewById(R.id.date);
            imageView = (ImageView)itemView.findViewById(R.id.imageView);
        }

        public void setDate(Long date) {
            textView.setText(date.toString());
        }

        public void setUrl(String url) {
            Picasso.with(itemView.getContext())
                    .load(url)
                    .resize(50, 50)
                    .centerCrop()
                    .into(imageView);
        }
    }
}

Link to the whole code

Answer 1

FirebaseUI 的最新版本 (3.x) 实现了与以前版本不同的初始化 FirebaseRecyclerAdapter 的方法。来自using the FirebaseRecyclerAdapter documentation：

首先，通过构建FirebaseRecyclerOptions 来配置适配器。在 在这种情况下，我们将继续我们的聊天示例：

 FirebaseRecyclerOptions<Chat> options =
                new FirebaseRecyclerOptions.Builder<Chat>()
                        .setQuery(query, Chat.class)
                        .build();

接下来创建FirebaseRecyclerAdapter 对象。你应该已经 有一个 ViewHolder 子类来显示每个项目。

因此，对于您的示例，您需要执行以下操作：

FirebaseRecyclerOptions<image_details> options =
        new FirebaseRecyclerOptions.Builder<image_details>()
                .setQuery(myRef, image_details.class)
                .build();

FirebaseRecyclerAdapter adapter = new FirebaseRecyclerAdapter<image_details, BlogViewHolder>(options) {
    @Override
    public BlogViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.individual_row, parent, false);

        return new BlogViewHolder(view);
    }

    @Override
    protected void onBindViewHolder(BlogViewHolder holder, int position, image_details model) {
        // Bind the image_details object to the BlogViewHolder
        // ...
    }
};

最后，FirebaseRecyclerAdapter 使用事件侦听器来监控 Firebase 查询的更改。要开始侦听数据，请调用 adapter.startListening() 和 adapter.stopListening() 以停止侦听器。建议分别在onStart() 和onStop() 中调用它们。更多详情请参阅FirebaseRecyclerAdapter lifecycle documentation。

Answer 2

您错过了启动活动的方法。 将此添加到onStart() 方法中：

firebaseRecyclerAdapter.startListening();

Answer 3

您好，您的错误是由于在此旁边找到的这些 () 中缺少参数

<image_details, BlogViewHolder>

所以您错过了 BlogViewHolder 类的另一个参数，因此我将添加这段代码并通过以下注释引用您缺少的参数：

FirebaseRecyclerAdapter<image_details, BlogViewHolder> adapter = new FirebaseRecyclerAdapter<image_details, BlogViewHolder>(
            image_details.class,
            R.layout.individual_row,
            BlogViewHolder.class //see this is missing so you should add it       
            myRef) {

Answer 4

这是正确的方法：

FirebaseRecyclerOptions<image_details> options =
    new FirebaseRecyclerOptions.Builder<image_details>()
            .setQuery(myRef, image_details.class)
            .build();

FirebaseRecyclerAdapter adapter = new FirebaseRecyclerAdapter<image_details, BlogViewHolder>(options) {
    @Override
    public BlogViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.individual_row, parent, false);

        return new BlogViewHolder(view);
    }

    @Override
    protected void onBindViewHolder(BlogViewHolder holder, int position, image_details model) {
        // Bind the image_details object to the BlogViewHolder
        // ...
    }
};

Answer 5

我遇到了同样的错误，这对我来说效果很好。希望它可以帮助某人

//loads data into recycler view onstart up
@Override
protected void onStart() {
    super.onStart();

    FirebaseRecyclerOptions<Data> options =
            new FirebaseRecyclerOptions.Builder<Data>()
                    .setQuery(dbReference, Data.class)
                    .build();

    FirebaseRecyclerAdapter firebaseRecyclerAdapter = new FirebaseRecyclerAdapter<Data, DataViewHolder>(options) {
        @Override
        public DataViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            View view = LayoutInflater.from(parent.getContext())
                    .inflate(R.layout.row, parent, false);

            return new DataViewHolder(view);
        }

        @Override
        protected void onBindViewHolder(@NonNull DataViewHolder holder, int position, @NonNull Data model) {
            // Bind the image_details object to the BlogViewHolder
            // ...
            holder.setDetails(getApplicationContext(), model.getName(), model.getDepartment(), model.getDescription());
        }
    };



    firebaseRecyclerAdapter.startListening();
    recyclerView.setAdapter(firebaseRecyclerAdapter);

}