[Android 개발] 안드로이드 RecyclerView(Adapter) 예제 코드 - Todo List 기본 틀

 

> 배운 기능

1. RecycleView 리스트에 EditText로 텍스트를 받아 add 해주기

2. 버튼 setOnClickListener를 통헤 list에서 delete 실행 

 

 

---

Listactivity.java

package com.example.todoapplication;

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

import android.annotation.SuppressLint;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

import com.example.myapplication.R;

import java.util.ArrayList;

public class ListActivity extends AppCompatActivity {
    Button main_bnt;
    EditText main_input;

    private ArrayList<TodolistData> todolistDataArrayList;
    private TodolistAdapter todolistAdapter;

    @SuppressLint("WrongViewCast")
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_list);

        RecyclerView recyclerView = (RecyclerView) findViewById(R.id.main_list);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));

        todolistDataArrayList = new ArrayList<>();
        todolistAdapter = new TodolistAdapter(todolistDataArrayList);
        recyclerView.setAdapter(todolistAdapter);

        main_bnt = (Button) findViewById(R.id.main_bnt);
        main_input = findViewById(R.id.main_input);

        main_bnt.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View view) {
                String todoString = main_input.getText().toString();
                if( todoString == null || "".equals(todoString)){
                    Toast.makeText(getApplicationContext(),"할일을 입력해주세요.", Toast.LENGTH_SHORT).show();
                    return;
                }
                TodolistData todolistData = new TodolistData(todoString);
                todolistDataArrayList.add(todolistData);
                todolistAdapter.notifyDataSetChanged();
                main_input.setText("");
            }
        });

    }
}

 

TodolistAdapter.java

package com.example.todoapplication;

import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.TextView;

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

import com.example.myapplication.R;

import java.util.ArrayList;

public class TodolistAdapter extends RecyclerView.Adapter<TodolistAdapter.ViewHolder> {
    private ArrayList<TodolistData> list;
    public TodolistAdapter(ArrayList<TodolistData> list) {
        this.list = list;
    }



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

    @Override
    public void onBindViewHolder(@NonNull TodolistAdapter.ViewHolder holder, int position) {
        holder.item_title.setText(list.get(position).getTodoitem());
        holder.item_btn.setOnClickListener(
                new View.OnClickListener() {
                    @Override
                    public void onClick(View view) {
                        list.remove(holder.getAdapterPosition());
                        notifyItemRemoved(holder.getAdapterPosition());
                        //현재있는 postion을 받아와서 삭제
                    }
                }

        );
    }

    public int getItemCount() {
        return ( null != list ? list.size() : 0 );
    }

    public class ViewHolder extends RecyclerView.ViewHolder {
        TextView item_title;
        Button item_btn;

        public ViewHolder(@NonNull View itemView) {
            super(itemView);
            item_title = itemView.findViewById(R.id.item_title);
            item_btn = itemView.findViewById(R.id.item_btn);
        }
    }
}

 

TodolistData.java

package com.example.todoapplication;

public class TodolistData {

    public TodolistData(String todoitem) {
        this.todoitem = todoitem;
    }

    public String getTodoitem() {
        return todoitem;
    }

    public void setTodoitem(String todoitem) {
        this.todoitem = todoitem;
    }

    private String todoitem;



}

 

activity_list.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.todoapplication.ListActivity">

    <TextView
        android:id="@+id/main_title"
        android:layout_width="171dp"
        android:layout_height="29dp"
        android:layout_marginTop="27dp"
        android:layout_marginBottom="20dp"
        android:text="TodoList"
        android:textAppearance="@style/TextAppearance.AppCompat.Large"
        app:layout_constraintBottom_toTopOf="@+id/main_list"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/main_list"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_marginBottom="20dp"
        app:layout_constraintBottom_toTopOf="@+id/main_bnt"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/main_title">

    </androidx.recyclerview.widget.RecyclerView>

    <EditText
        android:id="@+id/main_input"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="8dp"
        android:ems="10"
        android:inputType="textPersonName"
        android:text="Name"
        app:layout_constraintBottom_toBottomOf="@+id/main_bnt"
        app:layout_constraintEnd_toStartOf="@+id/main_bnt" />

    <Button
        android:id="@+id/main_bnt"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="66dp"
        android:layout_marginBottom="23dp"
        android:text="Button"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/main_list" />
</androidx.constraintlayout.widget.ConstraintLayout>

 

mainitem.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <TextView
        android:id="@+id/item_title"
        android:layout_width="267dp"
        android:layout_height="29dp"
        android:layout_weight="1"
        android:text="TextView" />

    <Button
        android:id="@+id/item_btn"
        style="@style/Widget.AppCompat.Button.Colored"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:background="#FFFFFF"
        android:text="Button"
        />
</LinearLayout>