在JavaFX中使用ProgressBar显示弹出窗口

Question

如何通过弹出显示我的进度条,并在进程完成时自动关闭.这是我的代码.

 Task<ProgressForm> task = new Task<ProgressForm>() {
            @Override 
            public ProgressForm call() throws InterruptedException{
                ProgressForm pf = new ProgressForm();
                for (int i = 1; i <= 10; i++) {
                    pf.activateProgressBar(this);
                    updateProgress(i, 10);
                }
            return pf;                
            }
        };

        task.setOnSucceeded(new EventHandler<WorkerStateEvent>() {
            @Override
            public void handle(WorkerStateEvent t) {
                ProgressForm pf = (ProgressForm)task.getValue();
                pf.getDialogStage().close();
            }
        });

        Thread th = new Thread(task);
        th.run();

进度表类:

private final Stage dialogStage;
private final ProgressBar pb = new ProgressBar();
private final ProgressIndicator pin = new ProgressIndicator();

public ProgressForm() {
    dialogStage = new Stage();
    dialogStage.initStyle(StageStyle.UTILITY);
    dialogStage.setResizable(false);
    dialogStage.initModality(Modality.APPLICATION_MODAL);

    // PROGRESS BAR
    final Label label = new Label();
    label.setText("alerto");

    pb.setProgress(-1F);
    pin.setProgress(-1F);

    final HBox hb = new HBox();
    hb.setSpacing(5);
    hb.setAlignment(Pos.CENTER);
    hb.getChildren().addAll(pb, pin);

    Scene scene = new Scene(hb);
    dialogStage.setScene(scene);
}

public void activateProgressBar(final Task task) throws InterruptedException {
    pb.progressProperty().bind(task.progressProperty());
    pin.progressProperty().bind(task.progressProperty());
    dialogStage.show();
}

public Stage getDialogStage() {
    return dialogStage;
}

这段代码的问题是

1. 如果我使用.show(),显示弹出是顺畅但没有进度条.
2. 如果我使用.showAndWait(),显示弹出窗口需要手动退出以弹出关闭但是显示进度条.

有关于此的任何想法/想法？

Answer 1

JavaFX中的多线程的两个规则是:

1. 必须在JavaFX Application线程上执行修改UI(创建Stage或更改属于场景图的节点的属性)的代码.违反此规则将抛出 s或导致不可预测的行为.IllegalStateException
2. 需要很长时间才能执行的代码应该在后台线程中执行(即不是FX应用程序线程).违反此规则将导致UI无响应.

您的代码违反了第一条规则,因为它ProgressForm在后台线程中调用构造函数.您应首先设置UI,显示对话框,然后启动后台线程.

请注意,无需progress将进度条和指示符的progress属性重复绑定到任务的属性.一旦它被约束,它将保持约束,除非你解除绑定.

现在修复你的代码非常困难,因为你的后台任务实际上并没有做任何需要的事情.这是一个暂停时你正在做的事情的版本:

import javafx.application.Application;
import javafx.concurrent.Task;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.ProgressBar;
import javafx.scene.control.ProgressIndicator;
import javafx.scene.layout.HBox;
import javafx.scene.layout.StackPane;
import javafx.stage.Modality;
import javafx.stage.Stage;
import javafx.stage.StageStyle;

public class ProgressDialogExample extends Application {

    @Override
    public void start(Stage primaryStage) {
        Button startButton = new Button("Start");
        startButton.setOnAction(e -> {
            ProgressForm pForm = new ProgressForm();

            // In real life this task would do something useful and return 
            // some meaningful result:
            Task<Void> task = new Task<Void>() {
                @Override
                public Void call() throws InterruptedException {
                    for (int i = 0; i < 10; i++) {
                        updateProgress(i, 10);
                        Thread.sleep(200);
                    }
                    updateProgress(10, 10);
                    return null ;
                }
            };

            // binds progress of progress bars to progress of task:
            pForm.activateProgressBar(task);

            // in real life this method would get the result of the task
            // and update the UI based on its value:
            task.setOnSucceeded(event -> {
                pForm.getDialogStage().close();
                startButton.setDisable(false);
            });

            startButton.setDisable(true);
            pForm.getDialogStage().show();

            Thread thread = new Thread(task);
            thread.start();
        });

        StackPane root = new StackPane(startButton);
        Scene scene = new Scene(root, 350, 75);
        primaryStage.setScene(scene);
        primaryStage.show();

    }

    public static class ProgressForm {
        private final Stage dialogStage;
        private final ProgressBar pb = new ProgressBar();
        private final ProgressIndicator pin = new ProgressIndicator();

        public ProgressForm() {
            dialogStage = new Stage();
            dialogStage.initStyle(StageStyle.UTILITY);
            dialogStage.setResizable(false);
            dialogStage.initModality(Modality.APPLICATION_MODAL);

            // PROGRESS BAR
            final Label label = new Label();
            label.setText("alerto");

            pb.setProgress(-1F);
            pin.setProgress(-1F);

            final HBox hb = new HBox();
            hb.setSpacing(5);
            hb.setAlignment(Pos.CENTER);
            hb.getChildren().addAll(pb, pin);

            Scene scene = new Scene(hb);
            dialogStage.setScene(scene);
        }

        public void activateProgressBar(final Task<?> task)  {
            pb.progressProperty().bind(task.progressProperty());
            pin.progressProperty().bind(task.progressProperty());
            dialogStage.show();
        }

        public Stage getDialogStage() {
            return dialogStage;
        }
    }

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