Question

嘿，我对android开发很新。你可以帮我解决下面的问题。这是我使用recyclerview的活动。但显然我在进入此活动后没有找到任何回收者视图，并且运行时错误说 RecyclerView：您必须覆盖onLayoutChildren（Recycler recycleler，State state）即将到来。 （API-23）

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import java.util.ArrayList;
import java.util.List;

public class ListActivity extends AppCompatActivity {

RecyclerView recyclerView;
RecyclerView.Adapter adapter;
RecyclerView.LayoutManager layoutManager;
String[] name,hostel;
ArrayList<DataProvider> arrayList=new ArrayList<DataProvider>();
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_list);
    recyclerView=(RecyclerView)findViewById(R.id.recycler_view);
    name= new String[]{"ravi", "teja", "kiran", "kumar"};
    hostel= new String[]{"umm","mmu","kjasd","ravi"};
    int i=0;
    for (String names : name )
    {
        DataProvider dataProvider= new DataProvider(names,hostel[i],R.mipmap.ic_launcher);
        arrayList.add(dataProvider);
        i++;
    }
    adapter= new AdapterClass(arrayList);
    recyclerView.setHasFixedSize(true);
    layoutManager= new RecyclerView.LayoutManager() {
        @Override
        public RecyclerView.LayoutParams generateDefaultLayoutParams() {
            return null;
        }

        @Override
        public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) {
            super.onLayoutChildren(recycler, state);

        }
    };

    recyclerView.setLayoutManager(layoutManager);
    recyclerView.setAdapter(adapter);

}
}

这是我的Adapter类

import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import java.util.ArrayList;


public class AdapterClass extends RecyclerView.Adapter<AdapterClass.RecyclerViewHolder> {
    private ArrayList<DataProvider> arrayList=new ArrayList<DataProvider>();

    public AdapterClass(ArrayList<DataProvider> arrayList)
    {
        this.arrayList = arrayList;
    }

    @Override
    public RecyclerViewHolder onCreateViewHolder(ViewGroup parent, int viewType)
    {
        View view= LayoutInflater.from(parent.getContext()).inflate(R.layout.list_element,parent,false);
        RecyclerViewHolder recyclerViewHolder= new RecyclerViewHolder(view);
        return recyclerViewHolder;
    }

    @Override
    public void onBindViewHolder(RecyclerViewHolder holder, int position)
    {
        DataProvider dataProvider=arrayList.get(position);
        holder.img.setImageResource(dataProvider.getImages());
        holder.tx_name.setText(dataProvider.getName());
        holder.tx_hostel.setText(dataProvider.getHostel());

    }



    @Override
    public int getItemCount() {
        return arrayList.size();
    }
    public static class RecyclerViewHolder extends RecyclerView.ViewHolder {
        ImageView img;
        TextView tx_name,tx_hostel;
        public RecyclerViewHolder(View itemView)
        {
            super(itemView);
            img=(ImageView)itemView.findViewById(R.id.imageView2);
            tx_name=(TextView)itemView.findViewById(R.id.name);
            tx_hostel=(TextView)itemView.findViewById(R.id.hostel);
        }
    }
}

这是DataProvider类

public class DataProvider {
    String name,hostel;
    int images;

    public DataProvider(String name, String hostel, int images) {
        this.name = name;
        this.hostel = hostel;
        this.images = images;
    }

    public String getName() {
        return name;
    }

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

    public String getHostel() {
        return hostel;
    }

    public void setHostel(String hostel) {
        this.hostel = hostel;
    }

    public int getImages() {
        return images;
    }

    public void setImages(int images) {
        this.images = images;
    }
}

这是listactivity.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_list"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.raviteja.crudjson.ListActivity">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recycler_view"
        android:scrollbars="vertical"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>

</RelativeLayout>

Answer 1

您没有说过您的RecyclerView应该具体看什么，但请尝试更改

layoutManager= new RecyclerView.LayoutManager() {
    @Override
    public RecyclerView.LayoutParams generateDefaultLayoutParams() {
        return null;
    }

    @Override
    public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) {
        super.onLayoutChildren(recycler, state);

    }
};

recyclerView.setLayoutManager(layoutManager);

到

recyclerView.setLayoutManager(new LinearLayoutManager(this));

运行时错误说要覆盖onLayoutChildren方法

1 个答案: