Flutter:从DataTableSource中的方法更新PaginatedDataTable？

Question

我想我已经接近解决这个问题了，但是我不确定该怎么做，也许还有更好的方法。

我有这个WeightDataSource，WeightDialog将简单地返回一个用户输入的数字。值被正确地存储在内存中，但当然屏幕没有更新，因为另一个类中的状态没有更改(如果我重新加载应用程序，我可以看到更改)。

class WeightDataSource extends DataTableSource {
  final List<Weight> _weights;
  final BuildContext context;

  WeightDataSource(this.context, this._weights);

  int _selectedCount = 0;

  _editCell(index, Weight _weight) async {
    print('$index $_weight');
    var updatedWeight = await Navigator.push(
        context,
        MaterialPageRoute(
          builder: (BuildContext context) =>
              WeightDialog(
                color: Colors.greenAccent,
                saveUpdate: 'update',
              ),
          fullscreenDialog: true,
        ));
    if (updatedWeight != null) {
      print('received weight: $updatedWeight');
      final prefs = await SharedPreferences.getInstance();
      var tempWeights = json.decode(prefs.getString('weights')) ?? {};
      tempWeights[_weight.date.toString()] = updatedWeight;
      prefs.setString('weights', json.encode(tempWeights));
      tempWeights = json.decode(prefs.getString('weights')) ?? {};
      print('updated weights $tempWeights');
    }
  }

// ...

我的想法是，如果我能以某种方式调用我的_loadAsyncData函数，屏幕就会更新，但我不确定如何从不同的类中做到这一点：

class HistoryPageState extends State<HistoryPage> {
  var calories = {};
  var weights = {};

  @override
  void initState() {
    super.initState();
    _loadAsyncData();
  }

  _loadAsyncData() async {
    SharedPreferences prefs = await SharedPreferences.getInstance();
    setState(() {
      calories = json.decode(prefs.getString('calories')) ?? {};
      weights = json.decode(prefs.getString('weights')) ?? {};
    });
  }

  // ...

  _updateWeights(BuildContext context, _weightsDataSource) async {
    var inputCalories = await Navigator.push(
        context,
        MaterialPageRoute(
          builder: (context) =>
              Scaffold(
                appBar: AppBar(title: Text('Update weights')),
                body: PaginatedDataTable(
                  header: Text('Weight Log'),
                  dataRowHeight: 30,
                  headingRowHeight: 30,
                  rowsPerPage: 3,
                  columns: <DataColumn>[
                    DataColumn(
                      label: Text('Date'),
                    ),
                    DataColumn(label: Text('Weight'))
                  ],
                  source: _weightsDataSource,
                ),
              ),

          fullscreenDialog: true,
        ));

    if (inputCalories != null) {
      print(inputCalories);
    }
  }

Answer 1

您是否尝试在数据源上调用notifyListeners()？这对我来说很管用。

我认为在您的例子中，它必须在_editCell()方法中。