使用sqflite从本地chinook.db创建Flutter ListView（已解决Future实例问题）

问题解决记录 #

• 已成功解决初始问题：之前调试时控制台输出I/flutter ( 5084): Instance of 'Future'的异常情况
• 解决思路参考了sqflite加载资产数据库的实现逻辑
• 特别感谢@aakash的帮助

实现代码 #

main.dart 核心代码片段 #

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 数据库操作实现 #

Future getSQL(String tableName) async {
  var databasesPath = await getDatabasesPath();
  var path = join(databasesPath, "chinook.db");

  // 检查数据库是否存在
  var exists = await databaseExists(path);

  if (!exists) {
    // 仅在首次启动应用时触发
    print("Creating new copy from asset");
    // 确保父目录存在
    try {
      await Directory(dirname(path)).create(recursive: true);
    } catch (_) {}

    // 从资源文件复制
    ByteData data = await rootBundle.load(join("assets", "chinook.db"));
    List<int> bytes = data.buffer.asUint8List(data.offsetInBytes, data.lengthInBytes);

    // 写入并刷新字节数据
    await File(path).writeAsBytes(bytes, flush: true);
  } else {
    print("Opening existing database");
  }

  // 打开数据库
  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);
}

内容的提问来源于stack exchange，提问作者Scott Summers