[英]Android RecyclerView not showing images or text on fragment
我正在尝试按照在线教程在片段上构建 RecyclerView,然后将图像和文本加载到卡片中。 我收到一个错误:
com.example.gena E/RecyclerView:没有连接适配器; 跳过布局
下面的代码是片段
package com.example.gena;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import androidx.fragment.app.Fragment;
import androidx.recyclerview.widget.DefaultItemAnimator;
import androidx.recyclerview.widget.GridLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import java.util.ArrayList;
import java.util.List;
public class ApprenticeFrag extends Fragment {
private RecyclerView recyclerView;
private ApprenticeAdapter adapter;
private List<ApprenticeData> mApprenticeList;
private ApprenticeData mApprenticeData;
public ApprenticeFrag() {
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.apprentice_frag, container, false);
recyclerView = rootView.findViewById(R.id.recyclerView);
mApprenticeList = new ArrayList<>();
mApprenticeData = new ApprenticeData("john doe1", getString(R.string.appr1_descr), R.drawable.appr1);
mApprenticeList.add(mApprenticeData);
mApprenticeData = new ApprenticeData("john doe2", getString(R.string.appr2_descr), R.drawable.appr2);
mApprenticeList.add(mApprenticeData);
mApprenticeData = new ApprenticeData("john doe3", getString(R.string.appr3_descr), R.drawable.appr3);
mApprenticeList.add(mApprenticeData);
mApprenticeData = new ApprenticeData("john doe4", getString(R.string.appr4_descr), R.drawable.appr4);
mApprenticeList.add(mApprenticeData);
mApprenticeData = new ApprenticeData("john doe5", getString(R.string.appr5_descr), R.drawable.appr5);
mApprenticeList.add(mApprenticeData);
mApprenticeData = new ApprenticeData("john doe6", getString(R.string.appr6_descr), R.drawable.appr6);
mApprenticeList.add(mApprenticeData);
mApprenticeData = new ApprenticeData("john doe7", getString(R.string.appr7_descr), R.drawable.appr7);
mApprenticeList.add(mApprenticeData);
mApprenticeData = new ApprenticeData("john doe8", getString(R.string.appr8_descr), R.drawable.appr8);
mApprenticeList.add(mApprenticeData);
mApprenticeData = new ApprenticeData("john doe9", getString(R.string.appr9_descr), R.drawable.appr9);
mApprenticeList.add(mApprenticeData);
mApprenticeData = new ApprenticeData("john doe10", getString(R.string.appr10_descr), R.drawable.appr10);
mApprenticeList.add(mApprenticeData);
mApprenticeData = new ApprenticeData("john doe11", getString(R.string.appr11_descr), R.drawable.appr11);
mApprenticeList.add(mApprenticeData);
adapter = new ApprenticeAdapter(getActivity(), mApprenticeList);
RecyclerView.LayoutManager mLayoutManager = new GridLayoutManager(getActivity(), 2);
recyclerView.setLayoutManager(mLayoutManager);
recyclerView.setItemAnimator(new DefaultItemAnimator());
recyclerView.setAdapter(adapter);
// Inflate the layout for this fragment
return inflater.inflate(R.layout.apprentice_frag, container, false);
}
}
我正在使用的适配器也如下:
package com.example.gena;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.cardview.widget.CardView;
import androidx.recyclerview.widget.RecyclerView;
import java.util.List;
public class ApprenticeAdapter extends RecyclerView.Adapter<ApprenticeViewHolder> {
private Context mContext;
private List<ApprenticeData> mApprenticeList;
ApprenticeAdapter(Context mContext, List<ApprenticeData> mApprenticeList) {
this.mContext = mContext;
this.mApprenticeList = mApprenticeList;
}
@NonNull
@Override
public ApprenticeViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View mView = LayoutInflater.from(parent.getContext()).inflate(R.layout.recyclerview_item_row, parent, false);
return new ApprenticeViewHolder(mView);
}
@Override
public void onBindViewHolder(final ApprenticeViewHolder holder, int position) {
holder.mImage.setImageResource(mApprenticeList.get(position).getApprenticePicture());
holder.mTitle.setText(mApprenticeList.get(position).getApprenticeName());
}
@Override
public int getItemCount() {
return 0;
}
}
class ApprenticeViewHolder extends RecyclerView.ViewHolder {
CardView mCardView = itemView.findViewById(R.id.cardview);
ImageView mImage;
TextView mTitle;
ApprenticeViewHolder(View itemView) {
super(itemView);
mImage = itemView.findViewById(R.id.ivImage);
mTitle = itemView.findViewById(R.id.tvTitle);
}
}
任何帮助将不胜感激。 谢谢
您面临的问题是因为在您的适配器类中:
@Override
public int getItemCount() {
return 0;
}
将以上几行更改为
@Override
public int getItemCount() {
return mApprenticeList.size();
}
它将解决您的问题。
此外,您需要更新onCreateView
方法中的最后一行
return inflater.inflate(R.layout.apprentice_frag, container, false);
到
return rootView;
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