JavaFX 游戏无法正确显示

Question

我的程序存在 JavaFx 问题。我的代码运行但只有“随机播放”按钮出现在窗口中。我的文本框或其他按钮或卡片都没有出现。我不确定为什么会出现这个问题，我没有收到任何运行时错误或编译错误。有人可以提供一些帮助吗？代码如下：

import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import javafx.scene.image.Image;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.HBox;
import javafx.scene.layout.Pane;
import javafx.stage.Stage;

import java.util.ArrayList;
import java.util.Collections;
import java.util.LinkedList;
import java.util.concurrent.atomic.AtomicReference;

public class Main extends Application {

   @Override
   public void start(Stage primaryStage) {

      ArrayList<Integer> deck;
      deck = new ArrayList<>();
      int i = 1;
      while(i < 52){
         deck.add(i);
         i++;
      }
      final AtomicReference<String> result = new AtomicReference<>("go.");

      Collections.shuffle(deck);

      BorderPane pane = new BorderPane();

      HBox top = new HBox(10);
      Label display = new Label(result.toString());
      Button btShuffle = new Button("Shuffle");
      btShuffle.setOnAction(
            e -> {
               Collections.shuffle(deck);
            });
      top.getChildren().add(display);
      top.getChildren().add(btShuffle);

      HBox center = new HBox(10);
      Card card1 = new Card(deck.get(0));
      center.getChildren().add(card1);

      Card card2 = new Card(deck.get(1));
      center.getChildren().add(card2);

      Card card3 = new Card(deck.get(2));
      center.getChildren().add(card3);

      Card card4 = new Card(deck.get(3));
      center.getChildren().add(card4);

      HBox bottom = new HBox(10);
      Label expression = new Label("Please Enter the expression: ");

      TextField tfExpress = new TextField();
      LinkedList<Object> expInput = new LinkedList<>();
      ArrayList<Character> signs = new ArrayList<>();
      signs.add('/');
      signs.add('+');
      signs.add('(');
      signs.add(')');
      signs.add('-');
      signs.add('^');
      signs.add('*');
      signs.add('%');
      String str = tfExpress.getText();
      char tempStor[] = str.toCharArray();
      for(char c: tempStor){
         expInput.add(c);
      }

       int express = (str != null && !"".equals(str)) ? Integer.parseInt(str) : -1;      



      expInput.removeIf(p-> p.equals(signs));

      Button btVerify = new Button("Verify");
      btVerify.setOnAction(
            (ActionEvent e) -> {
               if(card1.CardValue() == (int)expInput.get(0)
               && card2.CardValue() == (int)expInput.get(1)
               && card3.CardValue() == (int)expInput.get(2)
               && card4.CardValue() == (int)expInput.get(3)){
                  if(express == 24){
                     result.set("Correct");
                  }
                  else
                     result.set("Incorrect");

               }
               else
                  result.set("The numbers in the expression don't "
                     + "match the numbers in the set.");
            });

      pane.setTop(top);
      pane.setCenter(center);
      pane.setBottom(bottom);

      Scene scene = new Scene(pane);
      primaryStage.setTitle("24 card game");
      primaryStage.setScene(scene);
      primaryStage.show();
   }

   public class Card extends Pane {
      public int cardVal;
      Card(int card){
         Image cardImage;
         cardImage = new Image("card/"+ card +".png");
         cardVal = card;
      }

      public int CardValue(){
         int card = 0;

         if(cardVal <= 13){
            card = cardVal;
         }
         else if(cardVal > 13 && cardVal <= 26){
            card = cardVal - 13;
         }
         else if(cardVal > 26 && cardVal <= 39){
            card = cardVal - 26;
         }
         else if(cardVal > 39 && cardVal <= 52){
            card = cardVal - 39;
         }


         return card;
      }



   }



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

}

Answer 1

您的Card 类只是一个空的Pane，没有添加任何内容，因此它不会显示任何可见的内容。因此center 只包含一堆空窗格。

您实际上从未在 bottom HBox 中放置任何控件，所以它也是空的。

我确实看到了按钮旁边的Label，上面写着"go."。