如何在Dart的串列中選擇所需的元素，并更改該元素的資料

我有一個包含此類資料的陣列（實際上有更多資料）

          [ 
           {
                 serviceid: "979cf8e6",
                 amount: 1,
                 price: 0,
                 materialsPrice: 100,
                 enable: true,
                 chenge: true
            },
            {
                 serviceid: "979cf812",
                 amount: 1,
                 price: 15.5,
                 materialsPrice: 0,
                 enable: true,
                 chenge: false
            }
         ]

我的目標是在陣列的選定元素中將“啟用”更改為所需的狀態。為此，我將使用一個塊。也就是說，如果當我點擊事件時，我傳輸 (false and "979cf8e6") 。然后應該找到所需的元素（服務 = 979cf8e6）。并且這個元素應該在 false 上啟用。我試圖開始一些事情，但沒有成功。也許有人知道怎么做？））

    on<OnChangeStatusListItemClick>((event, emit) async {
      var serviceId = event.serviceId;//(my  serviceId here)
      var paymentStatus = event.status;//(my  new status here)
      var paymentDetails = state.listVariant; //(my  list here)
      PaymentDetailsModel? selected;

      paymentDetails = paymentDetails.map((paymentDetailsOne) {
       paymentDetailsOne.serviceid == serviceId;
        var selectedPaymentDetails = paymentDetailsOne.copyWith(enable: paymentStatus);
        return selectedPaymentDetails;
      }).toList();
      emit(state.copyWith(listVariant: paymentDetails));     
    });

我的 PaymentDetailsModel 模型（此模型用于 listVariant）

@freezed
class PaymentDetailsModel with _$PaymentDetailsModel {
  @JsonSerializable(fieldRename: FieldRename.none, explicitToJson: true)
  const factory PaymentDetailsModel({
    required String  serviceid,
    required double? price,
    required int?  minmal,
    required int  amount,
    required bool enable,
    required bool chenge,
  }) = _PaymentDetailsModel;

  factory PaymentDetailsModel.fromJson(Map<String, dynamic> json) =>
      _$PaymentDetailsModelFromJson(json);
}

uj5u.com熱心網友回復：

我想也許你會錯過如果其他檢查你的地圖功能，不太確定，但你可以嘗試：

on<OnChangeStatusListItemClick>((event, emit) async {
  final serviceId = event.serviceId;//(my  serviceId here)
  final paymentStatus = event.status;//(my  new status here)

  final paymentDetails = state.listVariant.map((paymentDetailsOne) {
    if ( paymentDetailsOne.serviceid == serviceId) {
      return paymentDetailsOne.copyWith(enable: paymentStatus);
    } else {
      return paymentDetailsOne;
    }
  }).toList();

  emit(state.copyWith(listVariant: paymentDetails));
});

uj5u.com熱心網友回復：

假設這是您的清單：

List<CustomModel> paymentDetails = [
    CustomModel(
        serviceid: "979cf8e6",
        amount: 1,
        price: 0,
        materialsPrice: 100,
        enable: true,
        change: true),
    CustomModel(
        serviceid: "979cf812",
        amount: 1,
        price: 15.5,
        materialsPrice: 0,
        enable: true,
        change: false),
  ];

你需要這樣做：

on<OnChangeStatusListItemClick>((event, emit) async {
      var serviceId = event.serviceId;
      var paymentStatus = event.status;
      var paymentDetails = state.listVariant;
      PaymentDetailsModel? selected;

      var item = paymentDetails.where((element) => element.serviceid == serviceId);
      if (item.isNotEmpty) {
        var index = paymentDetails.indexOf(item.first);
        paymentDetails[index] = CustomModel(
          serviceid: item.first.serviceid,
          amount: item.first.amount,
          price: item.first.price,
          materialsPrice: item.first.materialsPrice,
          enable: paymentStatus,
          chenge: item.first.chenge);
      }
      
      print("1 = ${paymentDetails.first.enable}"); // 1 = false
      emit(state.copyWith(listVariant: paymentDetails));     
    });

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