有条件的颜色背景JavaFX LineChart

我希望有条件地改变折线图的背景颜色。 在给定的示例中，我正在修改图表，以便Y值> = 3的任何部分在后台显示为红色阴影：

LineChartJavaFXTest.java

import javafx.application.Application; import javafx.scene.Scene; import javafx.scene.chart.LineChart; import javafx.scene.chart.NumberAxis; import javafx.scene.chart.XYChart; import javafx.stage.Stage; public class LineChartJavaFXTest extends Application { @Override public void start(Stage stage) { stage.setTitle("Line Chart Sample"); //defining the axes final NumberAxis xAxis = new NumberAxis(); final NumberAxis yAxis = new NumberAxis(); xAxis.setLabel("Seconds"); yAxis.setLabel("Volume"); //creating the chart final LineChart lineChart = new LineChart(xAxis,yAxis); lineChart.setTitle("Test Chart"); //defining a series XYChart.Series series = new XYChart.Series(); //populating the series with data series.getData().add(new XYChart.Data(1, 0)); series.getData().add(new XYChart.Data(2, 1)); series.getData().add(new XYChart.Data(3, 2)); series.getData().add(new XYChart.Data(4, 2)); series.getData().add(new XYChart.Data(5, 1)); series.getData().add(new XYChart.Data(6, 2)); series.getData().add(new XYChart.Data(7, 3)); series.getData().add(new XYChart.Data(8, 3)); series.getData().add(new XYChart.Data(9, 4)); series.getData().add(new XYChart.Data(10, 3)); series.getData().add(new XYChart.Data(11, 2)); series.getData().add(new XYChart.Data(12, 1)); Scene scene = new Scene(lineChart,800,600); scene.getStylesheets().add("LineChart.css"); lineChart.getData().add(series); lineChart.applyCss(); stage.setScene(scene); stage.show(); } public static void main(String[] args) { launch(args); } } 

LineChart.css

 .chart { -fx-padding: 10px; -fx-background-color: #010101; -fx-legend-visible: false; } .chart-content { -fx-padding: 30px; } .chart-title { -fx-text-fill: #ffffff; -fx-font-size: 1.6em; } .axis-label { -fx-text-fill: #ffffff; } .chart-plot-background { -fx-background-color:transparent; } .chart-vertical-grid-lines { -fx-stroke:#505050; } .chart-horizontal-grid-lines { -fx-stroke: #505050; } .chart-alternative-row-fill { -fx-fill:transparent; -fx-stroke: transparent; } .default-color0.chart-series-line { -fx-stroke: #0000ff; } .default-color0.chart-line-symbol { -fx-background-color: #0000ff, white; } 

结果

Answer 1

这个答案的灵感来自于JavaFX Linechart Color差异的解决方案。 我会建议你先通过它。

这个答案包括一个红色渐变，因为这是OP想要的。

解

 import javafx.application.Application; import javafx.collections.FXCollections; import javafx.collections.ObservableList; import javafx.scene.Scene; import javafx.scene.chart.LineChart; import javafx.scene.chart.NumberAxis; import javafx.scene.chart.XYChart; import javafx.scene.paint.Color; import javafx.scene.paint.CycleMethod; import javafx.scene.paint.LinearGradient; import javafx.scene.paint.Stop; import javafx.scene.shape.Polygon; import javafx.stage.Stage; public class LineChartJavaFXTest extends Application { public static void main(String[] args) { launch(args); } @Override public void start(Stage stage) { stage.setTitle("Line Chart Sample"); //defining the axes final NumberAxis xAxis = new NumberAxis(); final NumberAxis yAxis = new NumberAxis(); xAxis.setLabel("Seconds"); yAxis.setLabel("Volume"); //defining a series XYChart.Series series = new XYChart.Series(); //populating the series with data series.getData().add(new XYChart.Data(1, 0)); series.getData().add(new XYChart.Data(2, 1)); series.getData().add(new XYChart.Data(3, 2)); series.getData().add(new XYChart.Data(4, 2)); series.getData().add(new XYChart.Data(5, 1)); series.getData().add(new XYChart.Data(6, 2)); series.getData().add(new XYChart.Data(7, 3)); series.getData().add(new XYChart.Data(8, 3)); series.getData().add(new XYChart.Data(9, 4)); series.getData().add(new XYChart.Data(10, 3)); series.getData().add(new XYChart.Data(11, 2)); series.getData().add(new XYChart.Data(12, 1)); //creating the chart final LineChart lineChart = new LineChart(xAxis, yAxis, FXCollections.observableArrayList(series)) { @Override protected void layoutPlotChildren() { super.layoutPlotChildren(); Series series = (Series) getData().get(0); ObservableList> listOfData = series.getData(); for(int i = 0; i < listOfData.size()-1; i++) { // Check for Y value >=3 if(listOfData.get(i).getYValue().doubleValue() >= 3 && listOfData.get(i+1).getYValue().doubleValue() >= 3) { double x1 = getXAxis().getDisplayPosition(listOfData.get(i).getXValue()); double y1 = getYAxis().getDisplayPosition(0); double x2 = getXAxis().getDisplayPosition(listOfData.get((i + 1)).getXValue()); double y2 = getYAxis().getDisplayPosition(0); Polygon polygon = new Polygon(); LinearGradient linearGrad = new LinearGradient( 0, 0, 0, 1, true, // proportional CycleMethod.NO_CYCLE, // cycle colors new Stop(0.1f, Color.rgb(255, 0, 0, .3))); polygon.getPoints().addAll(new Double[]{ x1,y1, x1, getYAxis().getDisplayPosition(listOfData.get(i).getYValue()), x2,getYAxis().getDisplayPosition(listOfData.get((i+1)).getYValue()), x2,y2 }); getPlotChildren().add(polygon); polygon.toFront(); polygon.setFill(linearGrad); } } } }; lineChart.setTitle("Test Chart"); Scene scene = new Scene(lineChart, 800, 600); scene.getStylesheets().add("LineChart.css"); lineChart.applyCss(); stage.setScene(scene); stage.show(); } }