Question

如果xAxis虽然定义为String，但是如何在JavaFX 8中对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();
}

虽然这是一种显示问题的简单方法，但在我的代码中，我从一个巨大的excel文件中生成了BarChart。我正在使用的代码片段如下：

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);

请帮助，并提前感谢！

Answer 1

您需要对类别进行排序。

Collections.sort(xAxis.getCategories());

无法正常工作。

一种可行的方式如下所示：

// 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);

Answer 2

一种方法是从xAxis获取类别，并使用比较器对它们进行排序。虽然我的印象是，分类轴无论如何都是这样做的。

ObservableList<String>list = xAxis.getCategories();
Comparator<String> byValue = (e1, e2) -> Integer.compare(Integer.parseInt(e1), Integer.parseInt(e2));
xAxis.setCategories(list.sort(byValue));

在JavaFX 8 BarChart中订购xAxis类别

2 个答案: