flutter - Flutter-如何制作一张卡片列表，列出每年每个月的元素？

Question

费用运输工具

 class Transactions {
  final String id;

  final double amount;
  final String date;


  const Transactions({
    @required this.id,
    @required this.amount,
    @required this.date,
   
  });

  Transactions.fromMap(
    Map map,
  )   : this.id = map['id'],
        this.amount = map['amount'],
        this.date = map['date'],
       

  Map toMap() {
    return {
      // 'color': this.color,
      'id': this.id,
      'amount': this.amount,
      'date': this.date,
     
    };
  }
}

我正在尝试制作一张卡片 list ，以告知用户在当年的几个月中所花费的费用，如下所示:

我已经试过了

    return List.generate(2, (index) {
    
      final weekDay = DateTime.now().subtract(
        Duration(days: index),
      );
      var totalSum = 0.0;

      for (var i = 0; i < widget.transactions.length; i++) {
        if (DateTime.parse(widget.transactions[i].date).year == weekDay.year &&
            DateTime.parse(widget.transactions[i].date).month ==
                weekDay.month) {
          totalSum += widget.transactions[i].amount;
        }
      }

      // for (var i = 0; i < widget.transactions.length; i++) {
      //   totalSum = widget.transactions[index].amount + totalSum;
      // }

      return {
        'day': DateFormat.E().format(weekDay).substring(0, 1),
        'amount': totalSum,
      };
    }).reversed.toList();
  }

  double get totalSpending {
    return groupedTransactionValues.fold(0.0, (sum, item) {
      return sum + item['amount'];
    });
  }

但是它没有按照我想要的去做。
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Answer 1

嗯，最简单的方法之一就是将数据整理到一个列表中，其中每个元素每个月都有相关的详细信息(即金额)
例:

class Month{
 int month; //between 1 and 12
 double amount;
} 

因此，您只需要在构建函数中实现列表，如下所示:

build(context){
 return(
 //...
 child: List.builder(
 itemCount: yourlist.length
 itemBuilder: (context, index){
  return YourTileWidget(month: yourlist[index].month, amount: yourlist[index].amount)
    }
   ),
  //...
  );
}

希望这是您想要实现的目标!