Line.startXProperty() has the following syntax.
public final DoubleProperty startXProperty()
In the following code shows how to use Line.startXProperty() method.
import javafx.application.Application; import javafx.scene.Scene; import javafx.scene.layout.VBox; import javafx.scene.shape.Line; import javafx.stage.Stage; //from w ww . j a v a 2 s. c o m public class Main extends Application { @Override public void start(Stage stage) { VBox box = new VBox(); final Scene scene = new Scene(box, 300, 250); scene.setFill(null); Line line = new Line(); line.setStartX(0.0f); line.setStartY(0.0f); line.setEndX(100.0f); line.setEndY(100.0f); System.out.println(line.startXProperty()); box.getChildren().add(line); stage.setScene(scene); stage.show(); } public static void main(String[] args) { launch(args); } }