我测试了这个 css 代码来更改图表颜色,但是当我运行代码时,我得到了 NPE:
public class MainApp 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("Number of Month");
//creating the chart
final LineChart<Number,Number> lineChart = new LineChart<>(xAxis,yAxis);
// Look up first series fill
Node node = lineChart.lookup(".default-color0.chart-series-area-fill");
// Set the first series fill to translucent pale green
node.setStyle("-fx-fill: linear-gradient(#f2f2f2, #d4d4d4);"
+ " -fx-background-insets: 0 0 -1 0, 0, 1, 2;"
+ " -fx-background-radius: 3px, 3px, 2px, 1px;");
Node nodew = lineChart.lookup(".chart-series-area-line");
// Set the first series fill to translucent pale green
nodew.setStyle("-fx-stroke: #989898; -fx-stroke-width: 1px; ");
lineChart.setTitle("Stock Monitoring, 2010");
//defining a series
XYChart.Series series = new XYChart.Series();
series.setName("My portfolio");
//populating the series with data
series.getData().add(new XYChart.Data(1, 23));
series.getData().add(new XYChart.Data(2, 14));
series.getData().add(new XYChart.Data(3, 15));
series.getData().add(new XYChart.Data(4, 24));
series.getData().add(new XYChart.Data(5, 34));
series.getData().add(new XYChart.Data(6, 36));
series.getData().add(new XYChart.Data(7, 22));
series.getData().add(new XYChart.Data(8, 45));
series.getData().add(new XYChart.Data(9, 43));
series.getData().add(new XYChart.Data(10, 17));
series.getData().add(new XYChart.Data(11, 29));
series.getData().add(new XYChart.Data(12, 25));
Scene scene = new Scene(lineChart,800,600);
lineChart.getData().add(series);
stage.setScene(scene);
stage.show();
}
public static void main(String[] args) {
launch(args);
}
}
这行是问题所在:
node.setStyle("-fx-fill: linear-gradient(#f2f2f2, #d4d4d4);".........);
你能告诉我如何解决这个问题吗?此 CSS 代码用于 AreaChart。现在我想在 LineChart 中使用它。
P.S
我还尝试了示例中的CSS:
http://docs.oracle.com/javafx/2/charts/css-styles.htm http://docs.oracle.com/javafx/2/charts/css-styles.htm
Node node = lineChart.lookup(".default-color0.chart-series-line");
// Set the first series fill to translucent pale green
node.setStyle("-fx-stroke: #e9967a;");
但我又得到了 NPE。