处理大量数据的时候非常卡顿，是有什么操作秘诀我不会么？

[codepgq]

Chart(
                      data: lineData,
                      variables: {
                        'Date': Variable(
                          accessor: (Map map) => map['Date'] as String,
                          scale: OrdinalScale(tickCount: 5),
                        ),
                        'Close': Variable(
                          accessor: (Map map) =>
                          (map['Close'] ?? double.nan) as num,
                        ),
                      },
                      elements: [
                        AreaElement(
                          shape: ShapeAttr(value: BasicAreaShape(smooth: true)),
                          color: ColorAttr(
                              value: Defaults.colors10.first.withAlpha(80)),
                        ),
                        LineElement(
                          shape: ShapeAttr(value: BasicLineShape(smooth: true)),
                          size: SizeAttr(value: 0.5),
                        ),
                      ],
                      axes: [
                        Defaults.horizontalAxis,
                        Defaults.verticalAxis,
                      ],
                      selections: {
                        'touchMove': PointSelection(
                          on: {
                            GestureType.scaleUpdate,
                            GestureType.tapDown,
                            GestureType.longPressMoveUpdate
                          },
                          dim: Dim.x,
                        )
                      },
                      tooltip: TooltipGuide(
                        followPointer: [false, true],
                        align: Alignment.topLeft,
                        offset: const Offset(-20, -20),
                      ),
                      crosshair: CrosshairGuide(followPointer: [false, true]),
                    )

下面是数据源

final lineData = <Map<String, dynamic>>[];// {"Date": "04.01.2016", "Close": 126.12};
configLineData() {
  final now = DateTime.now();
  final random = Random();
  for (int i = 0; i<40000; i++) {
    final time = now.subtract(Duration(minutes: i));
    final timeStr = "${time.year}-${time.month.toString().padLeft(2,'0')}-${time.day.toString().padLeft(2,'0')} ${time.hour.toString().padLeft(2,'0')}:${time.minute.toString().padLeft(2,'0')}:00";
    lineData.add({"Date": timeStr, "Close": random.nextDouble() * 20 + 70});
  }
}

[dJani97]

It seems to me that you're generating all that data synchronously during the build method. Try doing it asynchronously and use something like a FutureBuilder to only show the chart once you have the adata generated.