我正在尝试创建一个方法，在用户单击舞台中的矩形后返回 . 但是，当单击矩形时调用wait（）然后再调用notify（）时，程序会冻结 . 如何在javafx中创建showAndWait（）方法？

我正在尝试创建一个类，询问多项选择问题，然后返回结果，下面的代码是这个类，并在我试图放置等待和通知调用的位置进行评论 .

import javafx.stage.Stage;
import javafx.scene.Scene;
import javafx.scene.layout.Pane;
import javafx.scene.shape.Rectangle;
import javafx.scene.paint.Color;
import javafx.scene.text.Text;
public class Question{
   int answer; //refers to the answer in the order of strings given
   // a = 1, b = 2, c = 3, d = 4

   String question;
   String a,b,c,d;

   public Question(String question, String a, String b, String c, String d, int answer){

      this.question = question;
      this.a = a;
      this.b = b;
      this.c = c;
      this.d = d;
      this.answer = answer;
   }

   private final double sideLength = 500;
   private volatile byte complete; //0 = no, 1 = true, -1 = false
   public synchronized boolean showAndWait(){
      complete = 0;
      Stage stage = new Stage();

      Pane pane = new Pane();
      Scene scene = new Scene(pane);

      stage.setScene(scene);

      stage.setResizable(false);
      stage.setMaxHeight(sideLength);
      stage.setMinHeight(sideLength);
      stage.setMaxWidth(sideLength);
      stage.setMinWidth(sideLength);



      double width = sideLength/3;
      double height = sideLength/5;

      double firstX = sideLength/9;
      double secondX = width + sideLength/9*2;

      double firstY = height + sideLength*2/5/3;
      double secondY = firstY * 2;


      Color base = Color.AQUAMARINE;
      Color wrong = Color.RED;
      Color right = Color.GREEN;



      Pane questionPane = makeAnswer(0,0,sideLength,sideLength/5, question, base, base);

      Pane ansA = makeAnswer(firstX, firstY, width, height,a,base, wrong);

      Pane ansB = makeAnswer(secondX, firstY, width, height,b,base, wrong);


      Pane ansC = makeAnswer(firstX, secondY, width, height,c,base, wrong);

      Pane ansD = makeAnswer(secondX, secondY, width, height,d,base, wrong);

      pane.getChildren().addAll(questionPane, ansA, ansB, ansC, ansD);
      stage.show();

      //wait here, check to see if completed

      System.out.println(complete);
      return complete == 1;  
   }

   private double textShiftX = 30;
   private double textShiftY = 30;
   private int characterLimit = 20;
   private double textChangeY = 10;
   private synchronized Pane makeAnswer(double x, double y,double width, double height, String s, Color base, Color afterClick){

      Pane temp = new Pane();
      temp.setLayoutX(x);
      temp.setLayoutY(y);

      Rectangle rD = new Rectangle(0, 0, width, height);
      rD.setFill(base);
      temp.getChildren().add(rD);

      for(int i=0;s.length() > 0;i++){
         String sTemp;
         if(s.length()>characterLimit){
            sTemp = s.substring(0,characterLimit);
            while(sTemp.charAt(sTemp.length()-1) != ' ')
               sTemp = sTemp.substring(0,sTemp.length()-1);
         }
         else
            sTemp = s;
         s = s.substring(sTemp.length());   

         Text t = new Text(textShiftX, textShiftY + textChangeY*i, sTemp);
         temp.getChildren().add(t);
      }



      rD.setOnMouseClicked( 
            (e)->{
               ((Rectangle)e.getSource()).setFill(afterClick);
               complete = 1;

               //notify
            });
      return temp;
   }
javafx synchronization