Question

使用sqflite从本地sql文件（chinook.db）创建列表视图最初的问题已解决： I / flutter（5084）：“未来”的实例参考代码：https://github.com/tekartik/sqflite/blob/master/sqflite/doc/opening_asset_db.md 感谢@aakash的帮助

main.dart
body: Container(
        child: FutureBuilder(
          future: getSQL("albums"),
          builder: (BuildContext context, AsyncSnapshot snapshot) {
            print(snapshot.data);
            if (snapshot.data == null) {
              return Container(child: Center(child: Text("Loading...")));
            } else {
              return ListView.builder(
                itemCount: snapshot.data.length,
                itemBuilder: (BuildContext context, int index) {
                  return ListTile(
                    title: Text(snapshot.data[index].title),
                  );
                },
              );
            }
          },
        ),
      ),

getSQL.dart 
Future getSQL(String tableName) async {
  var databasesPath = await getDatabasesPath();
  var path = join(databasesPath, "chinook.db");
// Check if the database exists
  var exists = await databaseExists(path);
  if (!exists) {
    // Should happen only the first time you launch your application
    print("Creating new copy from asset");
    // Make sure the parent directory exists
    try {
      await Directory(dirname(path)).create(recursive: true);
    } catch (_) {}
    // Copy from asset
    ByteData data = await rootBundle.load(join("assets", "chinook.db"));
    List<int> bytes =
        data.buffer.asUint8List(data.offsetInBytes, data.lengthInBytes);
    // Write and flush the bytes written
    await File(path).writeAsBytes(bytes, flush: true);
  } else {
    print("Opening existing database");
  }
// open the database
  var db = await openDatabase(path, readOnly: true);

  List<Map> list = await db.rawQuery('SELECT * FROM $tableName');
  List theList = [];
  for (var n in list) {
    theList.add(MyCategoryFinal(n["Title"]));
  }
  return (theList);
}
class MyCategoryFinal {
  final String title;
  MyCategoryFinal(this.title);
}

Answer 1

我通过为sqflite表创建一个类，在该地图列表上运行循环并将这些地图项转换为对象列表来解决此问题。

示例代码；

List<ItemBean> items = new List();
    list.forEach((result) {
      ItemBean story = ItemBean.fromJson(result);
      items.add(story);
    });

要创建对象，可以使用https://app.quicktype.io/。在这里，您可以传递json为其生成类。

之后，您可以使用FutureBuilder这样创建列表视图

       FutureBuilder(
          future: MyService.getAllItems(),
          builder: (context, snapshot) {
            if (!snapshot.hasData) {
              return Center(child: CircularProgressIndicator());
            }

            return ListView.builder(
              controller: listScrollController,
              itemCount: snapshot.data.length,
              reverse: true,
              itemBuilder: (context, index) {
                return Text(snapshot.data[index].itemName);
              },
            );
          },
        ),

Flutter使用本地sqlite文件创建列表视图

1 个答案: