JavaFX 折线图

JavaFX教程 – JavaFX折线图

折线图，一种双轴图表，显示了特定时间间隔内数据的动态。

对于双轴图表，我们可以定义一系列数据XYChart.Series类。

我们可以为每个系列分配一个名称，以便在图例中显示。

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 Main extends Application {

  @Override
  public void start(Stage stage) {
    final NumberAxis xAxis = new NumberAxis();
    final NumberAxis yAxis = new NumberAxis();
    xAxis.setLabel("Number of Month");
    final LineChart<Number, Number> lineChart = new LineChart<Number, Number>(
        xAxis, yAxis);

    lineChart.setTitle("Line Chart");
    XYChart.Series<Number, Number> series = new XYChart.Series<Number, Number>();
    series.setName("My Data");
    // populating the series with data
    series.getData().add(new XYChart.Data<Number, Number>(1, 23));
    series.getData().add(new XYChart.Data<Number, Number>(2, 114));
    series.getData().add(new XYChart.Data<Number, Number>(3, 15));
    series.getData().add(new XYChart.Data<Number, Number>(4, 124));

    Scene scene = new Scene(lineChart, 800, 600);
    lineChart.getData().add(series);

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

  public static void main(String[] args) {
    launch(args);
  }
}

上面的代码生成以下结果。

折线图创建

对于每个图表，我们可以设置标题及其相对于图表的位置。标题可以位于图表的顶部，右侧，左侧或底部。

我们可以以相同的方式指定图表图例的位置。

import javafx.application.Application;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.scene.Scene;
import javafx.scene.chart.CategoryAxis;
import javafx.scene.chart.LineChart;
import javafx.scene.chart.NumberAxis;
import javafx.scene.chart.XYChart;
import javafx.scene.chart.XYChart.Series;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;

public class Main extends Application {
  public static void main(String[] args) {
    launch(args);
  }

  @Override
  public void start(Stage primaryStage) {
    CategoryAxis xAxis = new CategoryAxis();
    NumberAxis yAxis = new NumberAxis();
    LineChart lineChart = new LineChart(xAxis, yAxis);
    lineChart.setData(getChartData());
    lineChart.setTitle("Chart");

    StackPane root = new StackPane();
    root.getChildren().add(lineChart);
    primaryStage.setScene(new Scene(root, 400, 250));
    primaryStage.show();
  }

  private ObservableList<XYChart.Series<String, Double>> getChartData() {
    double aValue = 10;
    double cValue = 20;
    ObservableList<XYChart.Series<String, Double>> answer = FXCollections
        .observableArrayList();
    Series<String, Double> aSeries = new Series<String, Double>();
    Series<String, Double> cSeries = new Series<String, Double>();
    aSeries.setName("a");
    cSeries.setName("C");

    for (int i = 2001; i < 2021; i++) {
      aSeries.getData().add(new XYChart.Data(Integer.toString(i), aValue));
      aValue = aValue + Math.random()*100 -50;
      cSeries.getData().add(new XYChart.Data(Integer.toString(i), cValue));
      cValue = cValue + Math.random()*100 -50 ;
    }
    answer.addAll(aSeries, cSeries);
    return answer;
  }
}

上面的代码生成以下结果。

折线图的类别

下面的代码显示了如何使用CategoryAxis类而不是NumberAxis类以在线形图中呈现非数字数据。

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.chart.CategoryAxis;
import javafx.scene.chart.LineChart;
import javafx.scene.chart.NumberAxis;
import javafx.scene.chart.XYChart;
import javafx.stage.Stage;

public class Main extends Application {

  @Override
  public void start(Stage stage) {
    final CategoryAxis xAxis = new CategoryAxis();
    final NumberAxis yAxis = new NumberAxis();
    xAxis.setLabel("Month");

    final LineChart<String, Number> lineChart = new LineChart<String, Number>(
        xAxis, yAxis);

    lineChart.setTitle("My Chart");

    XYChart.Series<String, Number> series = new XYChart.Series<String, Number>();
    series.setName("My data");

    series.getData().add(new XYChart.Data<String, Number>("Jan", 23));
    series.getData().add(new XYChart.Data<String, Number>("Feb", 114));
    series.getData().add(new XYChart.Data<String, Number>("Mar", 15));
    series.getData().add(new XYChart.Data<String, Number>("Apr", 24));
    series.getData().add(new XYChart.Data<String, Number>("May", 134));

    Scene scene = new Scene(lineChart, 800, 600);
    lineChart.getData().add(series);

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

  public static void main(String[] args) {
    launch(args);
  }
}

上面的代码生成以下结果。

将系列添加到折线图

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
 
import javax.imageio.ImageIO;
import javax.imageio.stream.ImageOutputStream;
 
import javafx.application.Application;
import javafx.embed.swing.SwingFXUtils;
import javafx.scene.Scene;
import javafx.scene.SnapshotParameters;
import javafx.scene.chart.CategoryAxis;
import javafx.scene.chart.LineChart;
import javafx.scene.chart.NumberAxis;
import javafx.scene.chart.XYChart;
import javafx.scene.image.WritableImage;
import javafx.stage.Stage;
 
 
public class LineChartSample extends Application {
 
    @Override 
    public void start(Stage stage) {
        stage.setTitle("Line Chart Sample");
        CategoryAxis xAxis = new CategoryAxis();
	    NumberAxis yAxis = new NumberAxis();
        xAxis.setLabel("Month");
        final LineChart<String,Number> lineChart = 
                new LineChart<String,Number>(xAxis,yAxis);
       
        lineChart.setTitle("Stock Monitoring, 2010");
                          
        XYChart.Series<String,Number> series1 = new XYChart.Series<String,Number>();
        series1.setName("Portfolio 1");
        
        series1.getData().add(new XYChart.Data<String,Number>("Jan", 23));
        series1.getData().add(new XYChart.Data("Feb", 14));
        series1.getData().add(new XYChart.Data("Mar", 15));
        series1.getData().add(new XYChart.Data("Apr", 24));
        series1.getData().add(new XYChart.Data("May", 34));
        series1.getData().add(new XYChart.Data("Jun", 36));
        series1.getData().add(new XYChart.Data("Jul", 22));
        series1.getData().add(new XYChart.Data("Aug", 45));
        series1.getData().add(new XYChart.Data("Sep", 43));
        series1.getData().add(new XYChart.Data("Oct", 17));
        series1.getData().add(new XYChart.Data("Nov", 29));
        series1.getData().add(new XYChart.Data("Dec", 25));
        
        XYChart.Series<String,Number> series2 = new XYChart.Series<String,Number>();
        series2.setName("Portfolio 2");
        series2.getData().add(new XYChart.Data("Jan", 33));
        series2.getData().add(new XYChart.Data("Feb", 34));
        series2.getData().add(new XYChart.Data("Mar", 25));
        series2.getData().add(new XYChart.Data("Apr", 44));
        series2.getData().add(new XYChart.Data("May", 39));
        series2.getData().add(new XYChart.Data("Jun", 16));
        series2.getData().add(new XYChart.Data("Jul", 55));
        series2.getData().add(new XYChart.Data("Aug", 54));
        series2.getData().add(new XYChart.Data("Sep", 48));
        series2.getData().add(new XYChart.Data("Oct", 27));
        series2.getData().add(new XYChart.Data("Nov", 37));
        series2.getData().add(new XYChart.Data("Dec", 29));

        XYChart.Series<String,Number> series3 = new XYChart.Series<String,Number>();
        series3.setName("Portfolio 3");
        series3.getData().add(new XYChart.Data("Jan", 44));
        series3.getData().add(new XYChart.Data("Feb", 35));
        series3.getData().add(new XYChart.Data("Mar", 36));
        series3.getData().add(new XYChart.Data("Apr", 33));
        series3.getData().add(new XYChart.Data("May", 31));
        series3.getData().add(new XYChart.Data("Jun", 26));
        series3.getData().add(new XYChart.Data("Jul", 22));
        series3.getData().add(new XYChart.Data("Aug", 25));
        series3.getData().add(new XYChart.Data("Sep", 43));
        series3.getData().add(new XYChart.Data("Oct", 44));
        series3.getData().add(new XYChart.Data("Nov", 45));
        series3.getData().add(new XYChart.Data("Dec", 44));
        Scene scene  = new Scene(lineChart,800,600);       
        lineChart.getData().addAll(series1, series2, series3);
        stage.setScene(scene);
        stage.show();
    }
    public static void main(String[] args) {
        launch(args);
    }
}

上面的代码生成以下结果。