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firebaserecycleradapter()无法应用于FirebaseRecyclerAdapter

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有人可以告诉那条特定行中的错误是什么 .

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

4 回答

  • 9

    你错过了开始活动的方法 . 在 onStart() 方法中添加:

    firebaseRecyclerAdapter.startListening();
    
  • 0

    你好你的错误是由于在这旁边找到的这些()中缺少一个参数

    <image_details, BlogViewHolder>
    

    所以你错过了BlogViewHolder类的另一个参数,所以我将添加这段代码并通过注释引用你缺少的参数:

    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) {
    
  • 2

    FirebaseUI的最新版本(3.x)实现了一种初始化 FirebaseRecyclerAdapter 的不同方法,而不是以前的版本 . 来自using the FirebaseRecyclerAdapter documentation

    首先,通过构建FirebaseRecyclerOptions来配置适配器 . 在这种情况下,我们将继续我们的聊天示例:FirebaseRecyclerOptions <Chat> options =
    新的FirebaseRecyclerOptions.Builder <Chat>()
    .setQuery(query,Chat.class)
    . Build ();
    接下来,创建FirebaseRecyclerAdapter对象 . 您应该已经有一个ViewHolder子类来显示每个项目 .

    所以,对于你的例子,你需要做类似的事情:

    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视Firebase查询的更改 . 要开始侦听数据,请调用 adapter.startListening()adapter.stopListening() 以停止侦听器 . 建议分别在 onStart()onStop() 中调用它们 . 有关详细信息,请参见FirebaseRecyclerAdapter lifecycle documentation .

  • 0

    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
            // ...
        }
    };
    

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