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);
}
}
}
4 回答
你错过了开始活动的方法 . 在
onStart()
方法中添加: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
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:
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:所以,对于你的例子,你需要做类似的事情:
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()
和adapter.stopListening()
以停止侦听器 . 建议分别在onStart()
和onStop()
中调用它们 . 有关详细信息,请参见FirebaseRecyclerAdapter lifecycle documentation .这是正确的方法: