java - Java fxml从表单返回值

Question

我遇到了一个问题，我似乎无法使用 fxml 从 javafx 中的新表单返回值。

我正在尝试拥有一个主窗体，它具有与连接 4 开始游戏、查看玩家、查看游戏、查看玩家游戏的游戏相关的 4 个功能

当我启动程序时，会弹出主菜单，然后我想点击“开始游戏”按钮。之后打开它会提示输入用户 1 的信息。然后它会弹出一个关于玩家信息的新表单。

我遇到的问题是，在单击接受按钮后，类中的变量变为 null 我尝试通过实例获取方法从主菜单类访问并返回主类。

在 ShowAndWait 行之后，变量似乎被清空了。如何在 windows 之后检索变量信息（以 c# 方式）

package Homework_5;

import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;

import java.util.ArrayList;

public class Connect4Window extends Application {
    ArrayList<Connect4Game> games = new ArrayList<>();

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

    @Override
    public void start(Stage primaryStage) throws Exception{
        Parent root = FXMLLoader.load(getClass().getResource("FXML_Files/MainMenu.fxml"));
        primaryStage.setTitle("Connect 4");
        primaryStage.setScene(new Scene(root));
        primaryStage.show();
    }
}

主菜单类

package Homework_5.FXML_Java_Classes;

import Homework_5.DataClasses.PersonData;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.Alert;
import javafx.scene.control.Button;

public class MainMenu {

    @FXML
    private Button btnViewGames;

    @FXML
    private Button btnViewPlayers;

    @FXML
    private Button btnStartGame;

    @FXML
    private Button btnViewPlayerGames;

    @FXML
    void startGame(ActionEvent event) {
        Alert alert = new Alert(Alert.AlertType.NONE, "Please enter player 1 info");
        alert.setHeaderText(null);
        alert.setTitle("Player 1 info");
        alert.showAndWait();

        PlayerInfo playerInfo = new PlayerInfo();
        playerInfo.Show();
        System.out.println(playerInfo.getTxtName()); //Shows null
        System.out.println(playerInfo.isInfoAccepted()); //Shows null
        System.out.println(playerInfo.getChkComputer()); //Shows null
        System.out.println(playerInfo.getColor()); //Shows null
    }

    @FXML
    void viewPlayers(ActionEvent event) {
        System.out.println("view players");
    }

    @FXML
    void viewPlayerGames(ActionEvent event) {
        System.out.println("view playergames");
    }

    @FXML
    void viewGames(ActionEvent event) {
        System.out.println("view games");
    }
}

玩家信息类

package Homework_5.FXML_Java_Classes;

import Homework_5.DataClasses.PersonData;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.scene.paint.Color;
import javafx.stage.Modality;
import javafx.stage.Stage;
import javafx.stage.StageStyle;

public class PlayerInfo {

    @FXML
    private Button btnAccept;

    @FXML
    private ColorPicker colorColorPicker;

    @FXML
    private CheckBox chkComputer;

    @FXML
    private TextField txtName;

    @FXML
    private Button btnClear;

    private boolean infoAccepted = false;

    public PlayerInfo(){

    }

    public PersonData Show()
    {
        try{
            FXMLLoader fxmlLoader = new FXMLLoader(getClass().getResource("../FXML_Files/PlayerInfo.fxml"));
            Parent root1 = fxmlLoader.load();
            Stage stage = new Stage();
            stage.initModality(Modality.WINDOW_MODAL);
            stage.setTitle("Enter Player Information");
            stage.setScene(new Scene(root1));
            stage.showAndWait();
            return new PersonData(txtName.getText(), colorColorPicker.getValue(), chkComputer.isSelected());
        } catch (Exception e)
        {
            e.printStackTrace();
        }
        return null;
    }

    @FXML
    void Accept(ActionEvent event) {
        if (txtName.getText().isEmpty()) {
            Alert alert = new Alert(Alert.AlertType.WARNING, "The name field is blank!\n\nPlease enter a name.");
            alert.setHeaderText(null);
            alert.setTitle("Name Blank");
            alert.showAndWait();
        } else {
            infoAccepted = true;
            Stage stage = (Stage) btnAccept.getScene().getWindow();
            stage.close();
        }
    }

    @FXML
    void Clear(ActionEvent event) {
        txtName.clear();
        colorColorPicker.setValue(Color.WHITE);
        chkComputer.setSelected(false);
    }

    public Color getColor() {
        return colorColorPicker.getValue();
    }

    public boolean getChkComputer() {
        return chkComputer.isSelected();
    }

    public String getTxtName() {
        return txtName.getText();
    }

    public boolean isInfoAccepted() {
        return infoAccepted;
    }
}

主菜单 fxml

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.geometry.*?>
<?import java.lang.*?>
<?import java.util.*?>
<?import javafx.scene.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>

<AnchorPane prefHeight="81.0" prefWidth="442.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" fx:controller="Homework_5.FXML_Java_Classes.MainMenu">
   <children>
      <Button fx:id="btnStartGame" layoutX="14.0" layoutY="14.0" mnemonicParsing="false" onAction="#startGame" prefHeight="55.0" prefWidth="86.0" text="Start Game" />
      <Button fx:id="btnViewPlayers" layoutX="110.0" layoutY="14.0" mnemonicParsing="false" onAction="#viewPlayers" prefHeight="55.0" prefWidth="86.0" text="View Players" />
      <Button fx:id="btnViewPlayerGames" layoutX="302.0" layoutY="14.0" mnemonicParsing="false" onAction="#viewPlayerGames" prefHeight="55.0" prefWidth="127.0" text="View Player Games" />
      <Button fx:id="btnViewGames" layoutX="206.0" layoutY="14.0" mnemonicParsing="false" onAction="#viewGames" prefHeight="55.0" prefWidth="86.0" text="View Games" />
   </children>
</AnchorPane>

播放器信息 fxml

<?xml version="1.0" encoding="UTF-8"?>

<?import java.lang.*?>
<?import java.util.*?>
<?import javafx.scene.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>

<AnchorPane prefHeight="201.0" prefWidth="213.0" rotate="-0.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" fx:controller="Homework_5.FXML_Java_Classes.PlayerInfo">
   <children>
      <Button fx:id="btnAccept" cancelButton="true" layoutX="14.0" layoutY="165.0" mnemonicParsing="false" onAction="#Accept" text="Accept" />
      <Button fx:id="btnClear" layoutX="156.0" layoutY="165.0" mnemonicParsing="false" onAction="#Clear" text="Clear" />
      <CheckBox fx:id="chkComputer" layoutX="57.0" layoutY="126.0" mnemonicParsing="false" text="Computer" />
      <ColorPicker fx:id="colorColorPicker" layoutX="57.0" layoutY="81.0" />
      <TextField fx:id="txtName" layoutX="57.0" layoutY="41.0" />
      <Label contentDisplay="CENTER" layoutX="14.0" layoutY="14.0" text="Please Enter User Information below" />
      <Label layoutX="14.0" layoutY="45.0" text="Name:" />
      <Label layoutX="14.0" layoutY="85.0" text="Color:" />
   </children>
</AnchorPane>

标签： javajavafxnetbeansfxml

Answer 1

您调用的PersonInfo实例Show()不是与PlayerInfo.fxml. 如果提供了属性FXMLLoader，则创建控制器类的新实例。fx:controller要访问此实例，请在调用 后使用FXMLLoader'方法。getControllerload()

例如，您可以创建一个static加载方法并使用它来创建控制器：

public class PlayerInfo {

    @FXML
    private Parent root1;

    public static PlayerInfo create() throws Exception {
        FXMLLoader fxmlLoader = new FXMLLoader(getClass().getResource("../FXML_Files/PlayerInfo.fxml"));
        fxmlLoader.load();
        return fxmlLoader.getController();
    }

    public PersonData Show() {
        Stage stage = new Stage();
        stage.initModality(Modality.WINDOW_MODAL);
        stage.setTitle("Enter Player Information");
        stage.setScene(new Scene(root1));
        stage.showAndWait();
        return new PersonData(txtName.getText(), colorColorPicker.getValue(), chkComputer.isSelected());
    }
    ...
}

<AnchorPane fx:id="root1" prefHeight="201.0" prefWidth="213.0" rotate="-0.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" fx:controller="Homework_5.FXML_Java_Classes.PlayerInfo">
    ...

PlayerInfo playerInfo = PlayerInfo.create();
playerInfo.Show();

或者，您可以使用<fx:root>并从“控制器”的构造函数加载 fxml，请参阅FXML 简介中的自定义组件方法