java - lineChartView 在 fragment 中findViewById

Question

当我尝试在 fragment 中添加图表时出现一些错误。我正在尝试在 fragment 中制作一个图表，该 fragment 将引用我在 XML 中为 fragment 创建的 LineChartView 元素。

我使用 hellochart 并阅读了教程。在那里解释了使用 Activity 来实现它。我如何将其实现为 fragment ？

LineChartView lineChartView;
String[] axisData = {"Jan", "Feb", "Mar", "Apr", "May", "June", "July", "Aug", "Sept",
            "Oct", "Nov", "Dec"};
int[] yAxisData = {50, 20, 15, 30, 20, 60, 15, 40, 45, 10, 90, 18};
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        lineChartView = findViewById(R.id.chart);
        List yAxisValues = new ArrayList();
        List axisValues = new ArrayList();
        Line line = new Line(yAxisValues).setColor(Color.parseColor("#9C27B0"));
        for (int i = 0; i < axisData.length; i++) {
            axisValues.add(i, new AxisValue(i).setLabel(axisData[i]));
        }
        for (int i = 0; i < yAxisData.length; i++) {
            yAxisValues.add(new PointValue(i, yAxisData[i]));
        }
        List lines = new ArrayList();
        lines.add(line);
        LineChartData data = new LineChartData();
        data.setLines(lines);
        Axis axis = new Axis();
        axis.setValues(axisValues);
        axis.setTextSize(16);
        axis.setTextColor(Color.parseColor("#03A9F4"));
        data.setAxisXBottom(axis);
        Axis yAxis = new Axis();
        yAxis.setName("Sales in millions");
        yAxis.setTextColor(Color.parseColor("#03A9F4"));
        yAxis.setTextSize(16);
        data.setAxisYLeft(yAxis);
        lineChartView.setLineChartData(data);
        Viewport viewport = new Viewport(lineChartView.getMaximumViewport());
        viewport.top = 110;
        lineChartView.setMaximumViewport(viewport);
        lineChartView.setCurrentViewport(viewport);
        return inflater.inflate(R.layout.fragment_events, container, false);
    }

findViewById 方法有一个错误，表明该方法无法解析。

Answer 1

更改 onCreateView 并告诉我它是否有效。首先声明View

private View paramView;

public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup 
container, @Nullable Bundle savedInstanceState) {

  paramView = inflater.inflate(R.layout.fragment_events, container, false);
  lineChartView = paramView.findViewById(R.id.chart);
  // Here comes all your code
  return paramView;
}