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ソースコードを追記しました。

2021/05/26 02:37

投稿

momiji0210

スコア60

test CHANGED Viewed

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test CHANGED Viewed

@@ -40,6 +40,52 @@
 ```Dart
+import 'package:flutter/material.dart';
+void main() => runApp(MyApp());
+class Todo {
+  final String title;
+  final String description;
+  Todo({@required this.title, @required this.description})
+      : assert(title != null),
+        assert(description != null);
+}
+class MyApp extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      debugShowCheckedModeBanner: false, // Debug文言の削除
+      title: 'Navigation',
+      home: ListScreen2(title: 'List'),
+    );
+  }
+}
 class Model {
   String title;
@@ -60,146 +106,486 @@
   });
-}
-// TopScreen一部
-onTap: () async {
-	var result = await Navigator.push(
-	    context,
-	    MaterialPageRoute(
-	        builder: (context) => NextScreen(model: model)));
-	//print(result);
-	setState(() {
-	    model = result;
-	    print('set state ' + model.title);
-	});
-},
-// NextScreen一部
-// 起動時に初期化
-void initState() {
-	super.initState();
-	// _initModel = model;
-	// これだと同じものを参照している？っぽい挙動
-	_initModel = Model(
-    	title: widget._model.title,
-    	subTitle: widget._model.subTitle,
-    	key: widget._model.key,
-	);
-}
-return WillPopScope(
-	onWillPop: () {
-	    print('onWillPop');
-	    Navigator.of(context).pop(_initModel);
-	    return Future.value(false);
-    },
-child: Column(
-	children: [
-		ElevatedButton(
-			child: Text('確定'),
-			onPressed: () {
-			    // TODO: 新規登録
-			    // 前の画面に戻る
-			    print('確定');
-			    if (Navigator.of(context).canPop()) {
-				    Navigator.of(context).pop(widget._model);
-				}
-			},
-		),
-		ElevatedButton(
-	        child: Text('キャンセル'),
-	        onPressed: () {
-	            print('キャンセル');
-	            // 前の画面に戻る
-	            widget._model = _initModel;
-	            if (Navigator.of(context).canPop()) {
-	            Navigator.of(context).pop(_initModel);
-	            }
-	        },
-	        style: ElevatedButton.styleFrom(
-	            primary: Colors.grey[200],
-	            onPrimary: Colors.black45,
-	        ),
-	    ),
-    ]
-)
+}
+class ListScreen2 extends StatefulWidget {
+  ListScreen2({Key key, this.title}) : super(key: key);
+  final String title;
+  @override
+  _ListScreenState2 createState() => _ListScreenState2();
+}
+class _ListScreenState2 extends State<ListScreen2> {
+  List<Model> modelList;
+  @override
+  // 起動時に初期化
+  void initState() {
+    super.initState();
+    modelList = [];
+    List<String> titleList = ["Title A", "Title B", "Title C"];
+    List<String> subTitleList = ["SubTitle A", "SubTitle B", "SubTitle C"];
+    for (int i = 0; i < 3; i++) {
+      Model model = Model(
+        title: titleList[i],
+        subTitle: subTitleList[i],
+        key: i.toString(),
+      );
+      modelList.add(model);
+    }
+  }
+  // リスト項目となる削除可能なウィジェットを作成
+  Widget buildItem(Model model, int index) {
+    return Dismissible(
+        key: Key('${model.key}'), // 項目が特定できるよう固有の文字列をキーとする
+        background: Container(
+          padding: EdgeInsets.only(
+            right: 48,
+          ),
+          alignment: AlignmentDirectional.centerEnd,
+          color: Colors.red,
+          child: Icon(
+            Icons.delete,
+            color: Colors.white,
+          ),
+        ), // スワイプしているアイテムの背景色
+        direction: DismissDirection.endToStart,
+        confirmDismiss: (direction) async {
+          // 削除するか確認する
+          return await showDialog(
+            context: context,
+            builder: (BuildContext context) {
+              return AlertDialog(
+                title: Text('確認ダイアログ'),
+                content: Text('本当に削除しますか？'),
+                actions: <Widget>[
+                  TextButton(
+                    onPressed: () => Navigator.of(context).pop(false),
+                    child: Text('CANCEL'),
+                  ),
+                  TextButton(
+                      onPressed: () => Navigator.of(context).pop(true),
+                      child:
+                          Text('DELETE', style: TextStyle(color: Colors.red))),
+                ],
+              );
+            },
+          );
+        },
+        onDismissed: (direction) {
+          // 削除時の処理
+          setState(() {
+            modelList.remove(model);
+          });
+        },
+        // 各項目のレイアウト
+        child: Card(
+            child: ListTile(
+          tileColor: Theme.of(context).cardColor,
+          title: Text('${model.title}',
+              style: TextStyle(
+                  fontWeight: FontWeight.bold, fontSize: 20, height: 1.2)),
+          subtitle: Text('${model.key} ${model.subTitle}'),
+          onTap: () async {
+            var result = await Navigator.push(
+                context,
+                MaterialPageRoute(
+                    builder: (context) => NextScreen2(model: model)));
+            //print(result);
+            setState(() {
+              if (result != null) {
+                model = result;
+                print('set state ' + model.title);
+              }
+            });
+          },
+        )));
+  }
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+        appBar: AppBar(
+          title: Text(widget.title),
+        ),
+        body: Container(
+            child: ReorderableListView(
+                onReorder: (int oldIndex, int newIndex) {
+                  if (newIndex > oldIndex) {
+                    // 元々下にあった要素が上にずれるため一つ分後退させる
+                    newIndex -= 1;
+                  }
+                  // 並び替え処理
+                  Model model = modelList[oldIndex];
+                  setState(() {
+                    modelList.removeAt(oldIndex);
+                    modelList.insert(newIndex, model);
+                  });
+                },
+                padding: EdgeInsets.only(top: 4),
+                children: modelList
+                    .asMap()
+                    .map((i, item) => MapEntry(i, buildItem(item, i)))
+                    .values
+                    .toList())
+            //],
+            ));
+  }
+}
+///////////
+class NextScreen2 extends StatefulWidget {
+  Model _model;
+  NextScreen2({Key key, @required Model model})
+      : assert(model != null),
+        this._model = model,
+        super(key: key);
+  @override
+  _NextScreenState2 createState() => _NextScreenState2();
+}
+class _NextScreenState2 extends State<NextScreen2> {
+  // 起動時に初期化
+  Model _initModel;
+  void initState() {
+    super.initState();
+    _initModel = Model(
+      title: widget._model.title,
+      subTitle: widget._model.subTitle,
+      key: widget._model.key,
+    );
+  }
+  @override
+  Widget build(BuildContext context) {
+    return WillPopScope(
+        onWillPop: () {
+          print('onWillPop');
+          Navigator.of(context).pop(_initModel);
+          return Future.value(false);
+        },
+        child: Scaffold(
+          appBar: AppBar(
+            title: Text('Edit'),
+          ),
+          body: Container(
+            padding: EdgeInsets.all(20),
+            child: Column(
+              mainAxisAlignment: MainAxisAlignment.start,
+              children: <Widget>[
+                // タイトル
+                TextField(
+                  controller: TextEditingController()
+                    ..text = widget._model.title,
+                  decoration: InputDecoration(
+                    hintText: 'タイトル',
+                    hintStyle: TextStyle(
+                      color: Colors.black26,
+                    ),
+                  ),
+                  onChanged: (text) {
+                    widget._model.title = text;
+                  },
+                ),
+                // 登録ボタン
+                Container(
+                  //padding: EdgeInsets.all(_PADDING_SIZE),
+                  padding: EdgeInsets.fromLTRB(0, 10, 0, 10),
+                  width: double.infinity, // 横幅いっぱいに広げる
+                  height: 60,
+                  child: ElevatedButton(
+                    child: Text('確定'),
+                    onPressed: () {
+                      // TODO: 新規登録
+                      // 前の画面に戻る
+                      print('確定');
+                      if (Navigator.of(context).canPop()) {
+                        Navigator.of(context).pop(widget._model);
+                      }
+                    },
+                  ),
+                ),
+                // キャンセルボタン
+                Container(
+                  //padding: EdgeInsets.all(_PADDING_SIZE),
+                  padding: EdgeInsets.fromLTRB(0, 10, 0, 10),
+                  width: double.infinity, // 横幅いっぱいに広げる
+                  height: 60,
+                  child: ElevatedButton(
+                    child: Text('キャンセル'),
+                    onPressed: () {
+                      print('キャンセル');
+                      // 前の画面に戻る
+                      widget._model = _initModel;
+                      if (Navigator.of(context).canPop()) {
+                        Navigator.of(context).pop(null);
+                      }
+                    },
+                    style: ElevatedButton.styleFrom(
+                      primary: Colors.grey[200],
+                      onPrimary: Colors.black45,
+                    ),
+                  ),
+                ),
+              ],
+            ),
+          ),
+        ));
+  }
+}
 ```