javafx - 在 JavaFX 8 BarChart 中订购 xAxis 类别

Question

在 JavaFX 8 中，当 xAxis 虽然定义为字符串但表示数字时，我如何对 BarChart 的 xAxis 进行排序或排序。例如:

@Override public void start(Stage stage) {
    stage.setTitle("Bar Chart Sample");
    final CategoryAxis xAxis = new CategoryAxis();
    final NumberAxis yAxis = new NumberAxis();
    final BarChart<String,Number> bc = 
        new BarChart<>(xAxis,yAxis);
    bc.setTitle("Country Summary");
    xAxis.setLabel("Number");       
    yAxis.setLabel("Value");

    XYChart.Series series1 = new XYChart.Series();
    series1.setName("Series-1");
    series1.getData().add(new XYChart.Data("2",200));
    series1.getData().add(new XYChart.Data("3",500));
    series1.getData().add(new XYChart.Data("4",100));

    XYChart.Series series2 = new XYChart.Series();
    series2.setName("Series-2");
    series2.getData().add(new XYChart.Data("1",900));
    series2.getData().add(new XYChart.Data("2",150));
    series2.getData().add(new XYChart.Data("3",50));
    series2.getData().add(new XYChart.Data("4",700));

    Scene scene  = new Scene(bc,800,600);
    bc.getData().addAll(series1, series2);

    stage.setScene(scene);
    stage.show();
}

尽管这是显示问题的一种简单方式，但在我的代码中，我从一个巨大的 excel 文件生成了条形图。下面是我使用的代码片段:

final ObservableList<XYChart.Series<String,Number>> barChartData =      FXCollections.observableArrayList();

            Iterator<Map.Entry<String, ArrayList<XYBean>>> it = xyBean.entrySet().iterator();
            while (it.hasNext()) {
                Map.Entry<String, ArrayList<XYBean>> entry = it.next();
                XYChart.Series series = new XYChart.Series<>();
                series.setName(entry.getKey());
                for (XYBean xybean : entry.getValue()) {
                    series.getData().add(new XYChart.Data(xybean.getxValue(), xybean.getyValue()));

                }

                barChartData.add(series);

            }
barChart.setData(barChartData);

请帮忙，提前致谢!

Answer 1

您需要对类别进行排序。

Collections.sort(xAxis.getCategories());

尽管如此，不起作用。

一种有效的方法如下所示:

// fill this whenever you add new data to the chart
private final Set<String> categories = new LinkedHashSet<>();

// after all data is added to the chart, sort the categories, set them manually and enable auto-ranging again (if needed)
final ObservableList<String> c = FXCollections.observableArrayList(categories);
Collections.sort(c);
xAxis.setCategories(c);
xAxis.setAutoRanging(true);