java.lang.IndexOutOfBoundsException：索引：0，大小：CardView 上的 0

Question

我收到此错误，因为我无法将我的包裹传递给另一个 activity。我希望将我的 cardView 中的图像和文本传递到每个 cardview 的新 activity 上。但是，我收到这个名为 java.lang.IndexOutOfBoundsException 的错误：索引：0，大小：0。我能得到一些帮助吗？谢谢。

这是错误代码

    E/AndroidRuntime: FATAL EXCEPTION: main
    Process: android.com.example.weddingappfinale, PID: 12694
    java.lang.IndexOutOfBoundsException: Index: 0, Size: 0
        at java.util.ArrayList.get(ArrayList.java:437)
        at android.com.example.weddingappfinale.MuaActivity.onItemClick(MuaActivity.java:55)
        at Adapters.MuaAdapter$MuaViewHolder.onClick(MuaAdapter.java:59)
        at android.view.View.performClick(View.java:7125)
        at android.view.View.performClickInternal(View.java:7102)
        at android.view.View.access00(View.java:801)
        at android.view.View$PerformClick.run(View.java:27336)
        at android.os.Handler.handleCallback(Handler.java:883)
        at android.os.Handler.dispatchMessage(Handler.java:100)
        at android.os.Looper.loop(Looper.java:214)
        at android.app.ActivityThread.main(ActivityThread.java:7356)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)
I/Process: Sending signal. PID: 12694 SIG: 9

Here is my Adapter:


    package Adapters;

import android.com.example.weddingappfinale.MuaView;
import android.com.example.weddingappfinale.R;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Filter;
import android.widget.Filterable;
import android.widget.ImageButton;
import android.widget.TextView;

import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;

import java.util.ArrayList;
import java.util.List;

public class MuaAdapter extends RecyclerView.Adapter<MuaAdapter.MuaViewHolder> implements Filterable {
    private ArrayList<MuaView> mMuaView;
    private ArrayList<MuaView> mMuaViewFull;
    private OnItemClickListener mListener;

    public interface OnItemClickListener {
        void onItemClick(int position);
    }

    public void setOnItemClickListener(OnItemClickListener listener) {
        mListener = listener;
    }

    public static class MuaViewHolder extends RecyclerView.ViewHolder {
        public ImageButton mImageButton;
        public TextView mTextView1;

        public MuaViewHolder(@NonNull View itemView, final OnItemClickListener listener) {
            super(itemView);
            mImageButton = itemView.findViewById(R.id.mua_imageButton);
            mTextView1 = itemView.findViewById(R.id.mua_title);

            itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    if (listener != null) {
                        int position = getAdapterPosition();
                        if (position != RecyclerView.NO_POSITION) {
                            listener.onItemClick(position);
                        }
                    }
                }
            });

            mImageButton.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    if (listener != null) {
                        int position = getAdapterPosition();
                        if (position != RecyclerView.NO_POSITION) {
                            listener.onItemClick(position);
                        }
                    }
                }
            });
        }
    }

    public MuaAdapter(ArrayList<MuaView> muaView) {
       mMuaView = muaView;
    }

    @Override
    public MuaViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.mua_view, parent, false);
        MuaViewHolder mvh = new MuaViewHolder(v, mListener);
        return mvh;
    }

    @Override
    public void onBindViewHolder(@NonNull MuaViewHolder holder, int position) {
        MuaView currentView = mMuaView.get(position);

        holder.mImageButton.setImageResource(currentView.getImageResource());
        holder.mTextView1.setText(currentView.getText1());
    }

    @Override
    public int getItemCount() {
        return mMuaView.size();
    }

    public Filter getFilter() {
        return MuaFilter;
    }

    private Filter MuaFilter = new Filter() {
        @Override
        protected FilterResults performFiltering(CharSequence constraint) {
            List<MuaView> filteredList = new ArrayList<>();

            if (constraint == null || constraint.length() == 0) {
                filteredList.addAll(mMuaViewFull);
            } else {
                String filterPattern = constraint.toString().toLowerCase().trim();

                for (MuaView item : mMuaViewFull) {
                    if (item.getText1().toLowerCase().contains(filterPattern)) {
                        filteredList.add(item);
                    }
                }
            }

            FilterResults results = new FilterResults();
            results.values = filteredList;

            return results;
        }

        @Override
        protected void publishResults(CharSequence constraint, FilterResults results) {
            mMuaView.clear();
            mMuaView.addAll((ArrayList) results.values);
            notifyDataSetChanged();

        }
    };
}

这是我的 Activity:

    package android.com.example.weddingappfinale;

import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.inputmethod.EditorInfo;

import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.SearchView;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import java.util.ArrayList;

import Adapters.MuaAdapter;
import CustomerActivities.CustomerActivity;

public class MuaActivity extends AppCompatActivity {

    private RecyclerView mRecyclerView;
    private MuaAdapter mAdapter;
    private RecyclerView.LayoutManager mLayoutManager;
    private ArrayList<MuaView> mMuaView = new ArrayList<>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.mua_list);

        getSupportActionBar().setTitle("Make Up Artists");
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);

        ArrayList<MuaView> muaView = new ArrayList<>();
        muaView.add(new MuaView(R.drawable.mua_image, "Shima Matin Bridal Services"));
        muaView.add(new MuaView(R.drawable.photography_image, "Aake Up Artist Pte Ltd"));
        muaView.add(new MuaView(R.drawable.mua_image, "Lake Up Artist 3Pte Ltd"));
        muaView.add(new MuaView(R.drawable.mua_image, "f Up Artist Pte Ltd"));

        // ArrayList

        mRecyclerView = findViewById(R.id.recycler_view_list);
        mRecyclerView.setHasFixedSize(true);
        mLayoutManager = new LinearLayoutManager(this);
        mAdapter = new MuaAdapter(muaView);

        mRecyclerView.setLayoutManager(mLayoutManager);
        mRecyclerView.setAdapter(mAdapter);

        mAdapter.setOnItemClickListener(new MuaAdapter.OnItemClickListener() {
            @Override
            public void onItemClick(int position) {
                Intent intent = new Intent(MuaActivity.this, CustomerActivity.class);
                intent.putExtra("Customer's Details", mMuaView.get(position));
                startActivity(intent);
            }

        });

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.search, menu);

        MenuItem searchItem = menu.findItem(R.id.action_search);
        SearchView searchView = (SearchView) searchItem.getActionView();

        searchView.setImeOptions(EditorInfo.IME_ACTION_DONE);

        searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
            @Override
            public boolean onQueryTextSubmit(String query) {
                return false;
            }

            @Override
            public boolean onQueryTextChange(String newText) {
                mAdapter.getFilter().filter(newText);
                return false;
            }
        });
        return true;
    }
}

这是我的新Activity：

    package CustomerActivities;

import android.com.example.weddingappfinale.MuaView;
import android.com.example.weddingappfinale.R;
import android.content.Intent;
import android.os.Bundle;
import android.widget.ImageButton;
import android.widget.TextView;

import androidx.appcompat.app.AppCompatActivity;

public class CustomerActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_customer);
        Intent intent = getIntent();
        MuaView muaView = intent.getParcelableExtra("Customer's Details");

        int imageRes = muaView.getImageResource();
        String line1 = muaView.getText1();

        ImageButton imageButton = findViewById(R.id.image_customer);
        imageButton.setImageResource(imageRes);

        TextView textView1 = findViewById(R.id.title_customer);
        textView1.setText(line1);

    }
}

这是我的包裹：

    package android.com.example.weddingappfinale;

import android.os.Parcel;
import android.os.Parcelable;

public class MuaView implements Parcelable {
    private int mImageResource;
    private String mText1;

    public MuaView(int imageResource, String text1) {
        mImageResource = imageResource;
        mText1 = text1;
    }

    protected MuaView(Parcel in) {
        mImageResource = in.readInt();
        mText1 = in.readString();
    }

    public static final Creator<MuaView> CREATOR = new Creator<MuaView>() {
        @Override
        public MuaView createFromParcel(Parcel in) {
            return new MuaView(in);
        }

        @Override
        public MuaView[] newArray(int size) {
            return new MuaView[size];
        }
    };

    public int getImageResource() {
        return mImageResource;
    }

    public String getText1() {
        return mText1;
    }

    @Override
    public int describeContents() {
        return 0;
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeInt(mImageResource);
        dest.writeString(mText1);
    }
}

Answer 1

对于适配器，您已给出 muaView 数组，其中包含 4 个元素。

 mAdapter = new MuaAdapter(muaView);

但是在这个 onClick() 中你试图从 mMuaView 中获取元素，它还是空的：

        public void onItemClick(int position) {
            Intent intent = new Intent(MuaActivity.this, CustomerActivity.class);
            intent.putExtra("Customer's Details", mMuaView.get(position));
            startActivity(intent);
        }

因此，使用相同的 arrayList 来初始化适配器并在您执行单击时从数组中获取数据。

java.lang.IndexOutOfBoundsException：索引：0，大小：CardView 上的 0

java.lang.IndexOutOfBoundsException: Index: 0, Size: 0 on CardView

android

parcelable

android-cardview

android-recyclerview