回答編集履歴

コード修正

2023/01/13 04:25

投稿

jimbe

スコア12648

test CHANGED Viewed

@@ -66,7 +66,7 @@
       String value = pref.getString(prefKey, null);
       if(value != null) {
-        for(String name : value.split(",")) add(name);
+        for(String name : value.split(",")) list.add(name);
       }
     }

コード修正

2023/01/13 04:20

投稿

jimbe

スコア12648

test CHANGED Viewed

@@ -47,7 +47,7 @@
   private static class Adapter extends RecyclerView.Adapter<Adapter.ViewHolder> {
     private class ViewHolder extends RecyclerView.ViewHolder {
-      final TextView nameView;
+      final CheckBox nameView;
       public ViewHolder(@NonNull View itemView) {
         super(itemView);
         nameView = itemView.findViewById(R.id.name);

コード修正

2023/01/13 04:16

投稿

jimbe

スコア12648

test CHANGED Viewed

@@ -97,7 +97,7 @@
     @NonNull
     @Override
     public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
-      return new ViewHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.card, parent, false));
+      return new ViewHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.card, null, false));
     }
     @Override

コード追加

2023/01/13 04:14

投稿

jimbe

スコア12648

test CHANGED Viewed

@@ -4,3 +4,180 @@
 add により view はビューの階層に組み込まれますが、それは root を根とするツリー状ですので、 1 つの view が複数回 1 つのツリー内に現れることは出来ません。(1つの view を複数のツリーに add することも出来ません。)
 やろうとされていることを考えますと、自分で生成・追加等をするよりも、 普通に RecyclerView 等を使ったほうが良いのではないでしょうか。
+---
+RecyclerView 版です。
+MainActivity.java
+```java
+import android.content.SharedPreferences;
+import android.os.Bundle;
+import android.view.*;
+import android.widget.*;
+import androidx.annotation.NonNull;
+import androidx.appcompat.app.*;
+import androidx.recyclerview.widget.RecyclerView;
+import java.util.*;
+public class MainActivity extends AppCompatActivity {
+  @Override
+  protected void onCreate(Bundle savedInstanceState) {
+    super.onCreate(savedInstanceState);
+    setContentView(R.layout.activity_main);
+    RecyclerView list = findViewById(R.id.list);
+    Adapter adapter = new Adapter(getPreferences(MODE_PRIVATE), "current");
+    list.setAdapter(adapter);
+    Button add = findViewById(R.id.add);
+    add.setOnClickListener(v -> {
+      View view = getLayoutInflater().inflate(R.layout.dialog, null, false);
+      EditText name = view.findViewById(R.id.nameEdit);
+      new AlertDialog.Builder(MainActivity.this)
+              .setView(view)
+              .setTitle("もちものついか")
+              .setPositiveButton("ついか", (d,i) -> adapter.add(name.getText().toString()))
+              .setNegativeButton("やめる", null)
+              .create()
+              .show();
+    });
+  }
+  private static class Adapter extends RecyclerView.Adapter<Adapter.ViewHolder> {
+    private class ViewHolder extends RecyclerView.ViewHolder {
+      final TextView nameView;
+      public ViewHolder(@NonNull View itemView) {
+        super(itemView);
+        nameView = itemView.findViewById(R.id.name);
+        Button delete = itemView.findViewById(R.id.delete);
+        delete.setOnClickListener(v -> remove(getAdapterPosition()));
+      }
+    }
+    private final SharedPreferences pref;
+    private final String prefKey;
+    private final List<String> list = new ArrayList<>();
+    Adapter(SharedPreferences pref, String prefKey) {
+      this.pref = pref;
+      this.prefKey = prefKey;
+      String value = pref.getString(prefKey, null);
+      if(value != null) {
+        for(String name : value.split(",")) add(name);
+      }
+    }
+    void add(String name) {
+      list.add(name);
+      store();
+      notifyItemInserted(list.size() - 1);
+    }
+    void remove(int position) {
+      if(position < 0) return;
+      list.remove(position);
+      store();
+      notifyItemRemoved(position);
+    }
+    private void store() {
+      pref.edit().putString(prefKey, getValue()).commit();
+    }
+    private String getValue() {
+      if(list.isEmpty()) return null;
+      StringJoiner sj = new StringJoiner(",");
+      for(String value : list) sj.add(value);
+      return sj.toString();
+    }
+    @NonNull
+    @Override
+    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
+      return new ViewHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.card, parent, false));
+    }
+    @Override
+    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
+      holder.nameView.setText(list.get(position));
+    }
+    @Override
+    public int getItemCount() {
+      return list.size();
+    }
+  }
+}
+```
+res/layout/activity_main.xml
+```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=".MainActivity">
+  <androidx.recyclerview.widget.RecyclerView
+      android:id="@+id/list"
+      android:layout_width="match_parent"
+      android:layout_height="match_parent"
+      android:layout_marginBottom="70dp"
+      app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
+      app:layout_constraintBottom_toTopOf="@id/add"
+      app:layout_constraintEnd_toEndOf="parent"
+      app:layout_constraintStart_toStartOf="parent"
+      app:layout_constraintTop_toTopOf="parent" />
+  <Button
+      android:id="@+id/add"
+      android:layout_width="wrap_content"
+      android:layout_height="wrap_content"
+      android:layout_marginBottom="10dp"
+      android:text="✙　ついか"
+      app:layout_constraintBottom_toBottomOf="parent"
+      app:layout_constraintEnd_toEndOf="parent"
+      app:layout_constraintStart_toStartOf="parent" />
+</androidx.constraintlayout.widget.ConstraintLayout>
+```
+res/layout/card.xml
+```xml
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.cardview.widget.CardView 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"
+    android:layout_margin="10dp"
+    app:cardCornerRadius="10dp"
+    app:cardElevation="10dp">
+  <RelativeLayout
+      android:layout_width="match_parent"
+      android:layout_height="wrap_content"
+      android:padding="10dp">
+    <CheckBox
+        android:id="@+id/name"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:textColor="@android:color/holo_purple"
+        android:textFontWeight="1000"
+        android:textSize="20dp" />
+    <Button
+        android:id="@+id/delete"
+        android:layout_width="50dp"
+        android:layout_height="50dp"
+        android:layout_alignParentEnd="true"
+        android:layout_alignParentRight="true"
+        android:text="✖" />
+  </RelativeLayout>
+</androidx.cardview.widget.CardView>
+```