How to delete or remove CardView from RecyclerView? Android Studio

问题

On my RecyclerView are CardViews containing details about a certain exercise and on my CardView, there is an ImageDeleteBtn beside it. How do I delete the CardView from the RecyclerView and on Firebase?

This is my Adapter

package com.lim.fiture.fiture.adapters;

import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.EditText;
import android.widget.ImageButton;

import com.lim.fiture.fiture.R;
import com.lim.fiture.fiture.models.Exercise;

import java.util.ArrayList;

public class AdminActivityAdapter extends RecyclerView.Adapter <AdminActivityAdapter.ViewHolder>{

    Context context;
    public ArrayList <Exercise> exercises;
    private OnItemClicked onClick;

    //make interface like this
    public interface OnItemClicked {
        void onItemClick(int position);
    }

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.activity_admin_adapter,parent,false);
        AdminActivityAdapter.ViewHolder viewHolder = new AdminActivityAdapter.ViewHolder(view);
        return viewHolder;
    }

    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {

        holder.exerciseName.setText(exercises.get(position).getExerciseName());
        holder.mainMuscleGroup.setText(exercises.get(position).getMainMuscleGroup());
        holder.otherMuscleGroup.setText(exercises.get(position).getOtherMuscleGroup());
        holder.type.setText(exercises.get(position).getType());
        holder.equipment.setText(exercises.get(position).getEquipment());
        holder.difficulty.setText(exercises.get(position).getDifficulty());
        holder.deleteExercise.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                onClick.onItemClick(position);
            }
        });

    }

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


    public class ViewHolder extends RecyclerView.ViewHolder {
        private EditText exerciseName, mainMuscleGroup, otherMuscleGroup, type, equipment, difficulty;
        private ImageButton deleteExercise;
        public ViewHolder(View itemView) {
            super(itemView);

            exerciseName = itemView.findViewById(R.id.exerciseName);
            mainMuscleGroup = itemView.findViewById(R.id.mainMuscleGroup);
            otherMuscleGroup = itemView.findViewById(R.id.otherMuscleGroup);
            type = itemView.findViewById(R.id.type);
            equipment = itemView.findViewById(R.id.equipment);
            difficulty = itemView.findViewById(R.id.difficulty);
            deleteExercise = itemView.findViewById(R.id.deleteBtn);

        }
    }
}

This is my Activity

package com.lim.fiture.fiture.activities;

import android.content.ClipData;
import android.content.Intent;
import android.graphics.Color;
import android.graphics.drawable.ColorDrawable;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.ActionBar;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.helper.ItemTouchHelper;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.support.v7.app.AppCompatActivity;
import android.widget.ImageButton;
import android.widget.Toast;

import com.google.android.gms.tasks.OnFailureListener;
import com.google.android.gms.tasks.OnSuccessListener;
import com.google.firebase.auth.AuthResult;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.database.ChildEventListener;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.lim.fiture.fiture.R;
import com.lim.fiture.fiture.adapters.AdminActivityAdapter;
import com.lim.fiture.fiture.adapters.ExercisesAdapter;
import com.lim.fiture.fiture.models.Exercise;

import java.util.ArrayList;



public class AdminActivity extends AppCompatActivity implements View.OnClickListener, AdminActivityAdapter.OnItemClicked {

    private RecyclerView exercisesList;
    private AdminActivityAdapter adapter;
    private RecyclerView.LayoutManager layoutManager;
    private FloatingActionButton addExerciseBtn;
    private ExercisesAdapter exercisesAdapter;
    private ArrayList<Exercise> exercises = new ArrayList<>();

    //TODO: instance variables for firebase database
    private DatabaseReference exerciseReference;
    private static final String TAG = "AdminActivity";
    private FirebaseAuth mAuth;

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

        mAuth = FirebaseAuth.getInstance();
        exerciseReference = FirebaseDatabase.getInstance().getReference("Exercises");
        findViews();
        loadExercises();
    }

    @Override
    protected void onStart() {
        super.onStart();
        FirebaseUser user = mAuth.getCurrentUser();
        if (user != null) {
            // do your stuff
        } else {
            signInAnonymously();
        }
    }

    private void signInAnonymously() {
        mAuth.signInAnonymously().addOnSuccessListener(this, new OnSuccessListener<AuthResult>() {
            @Override
            public void onSuccess(AuthResult authResult) {
                // do your stuff
            }
        })
            .addOnFailureListener(this, new OnFailureListener() {
                @Override
                public void onFailure(@NonNull Exception exception) {
                    Log.e(TAG, "signInAnonymously:FAILURE", exception);
                }
            });
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()) {
            case R.id.addExerciseBtn:
                startActivity(new Intent(this, AddExerciseStepOne.class));
                break;
        }
    }

    public void findViews() {
        addExerciseBtn = findViewById(R.id.addExerciseBtn);
        addExerciseBtn.setOnClickListener(this);
        exercisesList = findViewById(R.id.exercisesList);
        layoutManager = new LinearLayoutManager(this);
        exercisesList.setLayoutManager(layoutManager);

        ActionBar bar = getSupportActionBar();
        bar.setBackgroundDrawable(new ColorDrawable(Color.parseColor("#2980b9")));
        bar.setTitle("Fiture Admin");
    }

    public void loadExercises() {
        exerciseReference.addChildEventListener(new ChildEventListener() {
            @Override
            public void onChildAdded(DataSnapshot dataSnapshot, String s) {
                Exercise exercise = dataSnapshot.getValue(Exercise.class);
                Log.d(TAG, exercise.toString());
                exercises.add(exercise);
                exercisesAdapter = new ExercisesAdapter(AdminActivity.this, exercises);
                exercisesList.setAdapter(exercisesAdapter);

            }

            @Override
            public void onChildChanged(DataSnapshot dataSnapshot, String s) {

            }

            @Override
            public void onChildRemoved(DataSnapshot dataSnapshot) {

            }

            @Override
            public void onChildMoved(DataSnapshot dataSnapshot, String s) {

            }

            @Override
            public void onCancelled(DatabaseError databaseError) {

            }

        });
    }

    @Override
    public void onItemClick(int position) {

    }
}

Anyone knows how to this? It'll be a very huge help for me. Thanks ahead!

回答1:

Solution:

Inside your onBindView(..) write like this:

holder.deleteExercise.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        exercises.remove(holder.getAdapterPosition());
        notifyItemRemoved(holder.getAdapterPosition());
        notifyItemRangeChanged(holder.getAdapterPosition(), exercises.size());
    }
});

Hope it Helps.

回答2:

In your onBind Do this.

holder.deleteExercise.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        exercises.remove(position);
        notifyDataSetChanged()
    }
});

回答3:

try this, use it with a tag:

holder.deleteExercise.setTag(position);
holder.deleteExercise.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {       
        exercises.remove((int)v.getTag());
        notifyDataSetChanged()
    }
});

回答4:

Try this, hope it helps.

holder.deleteExercise.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        exercises.remove(exercises.get(position));
        notifyDataSetChanged()
    }
});

回答5:

Try the following solution:

@Override
public void onItemClick(int position) {
    exercises.removeAt(postion)
    yourList.adapter.notifyItemRangeChanged(deletedPosition, yourList.size )
}

Hope this solution will work.

来源：https://stackoverflow.com/questions/52404324/how-to-delete-or-remove-cardview-from-recyclerview-android-studio