ProgressBar(double progress) constructor from ProgressBar has the following syntax.
public ProgressBar(double progress)
In the following code shows how to use ProgressBar.ProgressBar(double progress) constructor.
import javafx.application.Application; import javafx.beans.value.ChangeListener; import javafx.beans.value.ObservableValue; import javafx.concurrent.Task; import javafx.event.ActionEvent; import javafx.event.EventHandler; import javafx.geometry.Pos; import javafx.scene.Group; import javafx.scene.Scene; import javafx.scene.control.Button; import javafx.scene.control.Label; import javafx.scene.control.ProgressBar; import javafx.scene.layout.BorderPane; import javafx.scene.layout.HBox; import javafx.scene.paint.Color; import javafx.stage.Stage; //from www . ja v a2 s. c om public class Main extends Application { Task copyWorker; public static void main(String[] args) { Application.launch(args); } @Override public void start(Stage primaryStage) { Group root = new Group(); Scene scene = new Scene(root, 330, 120, Color.WHITE); BorderPane mainPane = new BorderPane(); root.getChildren().add(mainPane); final Label label = new Label("Files Transfer:"); final ProgressBar progressBar = new ProgressBar(0); final HBox hb = new HBox(); hb.setSpacing(5); hb.setAlignment(Pos.CENTER); hb.getChildren().addAll(label, progressBar); mainPane.setTop(hb); final Button startButton = new Button("Start"); final Button cancelButton = new Button("Cancel"); final HBox hb2 = new HBox(); hb2.setSpacing(5); hb2.setAlignment(Pos.CENTER); hb2.getChildren().addAll(startButton, cancelButton); mainPane.setBottom(hb2); startButton.setOnAction(new EventHandler<ActionEvent>() { public void handle(ActionEvent event) { startButton.setDisable(true); progressBar.setProgress(0); cancelButton.setDisable(false); copyWorker = createWorker(); progressBar.progressProperty().unbind(); progressBar.progressProperty().bind(copyWorker.progressProperty()); copyWorker.messageProperty().addListener(new ChangeListener<String>() { public void changed(ObservableValue<? extends String> observable, String oldValue, String newValue) { System.out.println(newValue); } }); new Thread(copyWorker).start(); } }); cancelButton.setOnAction(new EventHandler<ActionEvent>() { public void handle(ActionEvent event) { startButton.setDisable(false); cancelButton.setDisable(true); copyWorker.cancel(true); progressBar.progressProperty().unbind(); progressBar.setProgress(0); System.out.println("cancelled."); } }); primaryStage.setScene(scene); primaryStage.show(); } public Task createWorker() { return new Task() { @Override protected Object call() throws Exception { for (int i = 0; i < 10; i++) { Thread.sleep(2000); updateMessage("2000 milliseconds"); updateProgress(i + 1, 10); } return true; } }; } }