java - 无法更改标签和按钮值

Question

我正在使用 JavaFx 编写一个简单的问答游戏应用程序。我想使用列表和表格中的数据在标签和按钮上设置文本。

我创建了三个类：Main、Controller 和 Quiz.fxml。我对通信类和方法有疑问。在“Main.java”中，我创建了对象“Controller controller = new Controller()”，并从“Controller.java”类中调用了“controller.setText”方法。

现在，我有几个选择：

-如果构造函数'public Controller(){}'应用程序中的declate list(ArrayList questions)和tab(String[][] answers)不起作用，我在这一行出现错误“”

-如果在“Text()”方法中声明所有内容（列表、选项卡和在标签上设置文本）应用程序运行但值按钮和标签未更改

- 如果我在“setData()”中声明列表和选项卡，接下来我想从“Text()”方法更改按钮和标签值，我看不到列表，我必须在中声明相同的列表“问题” '文本（）'

public class Main extends Application {



@Override
public void start(Stage primaryStage) throws Exception {
    try {

        Parent root = FXMLLoader.load(getClass().getResource("/Controller/Quiz.fxml"));
        Scene scene = new Scene(root,500,400)
        primaryStage.setScene(scene);
        primaryStage.show();
    } catch(Exception e) {
        e.printStackTrace();
    }
}
public static void main(String[] args) {
    launch(args);
    Controller controller = new Controller();
    controller.Text();}

控制器类：

public class Controller  {

@FXML private Label questionLabel;
@FXML private RadioButton answer_btn1;
@FXML private RadioButton answer_btn2;
@FXML private RadioButton answer_btn3;
@FXML private RadioButton answer_btn4;
@FXML private Button nextBtn;



public void Text() {
    List <String> questions = new ArrayList<String>();

    questions.add("pytanie1");
    questions.add("pytanie2");
    questions.add("pytanie3");
    questions.add("pytanie4");
    questions.add("pytanie5");
    questions.add("pytanie6");
    questions.add("pytanie7");
    questions.add("pytanie8");
    questions.add("pytanie9");
    questions.add("pytanie10");

    String[][] answers = new String[1][4];
    answers[1][1] = "a) odp";
    answers[1][2] = "b) odp";
    answers[1][3] = "c) odp";
    answers[1][4] = "d) odp";


    questionLabel.setText("");

    questionLabel.setText(questionLabel.getText()+answers[1][1]);
    answer_btn1.setText("aaa");
}

我要如何更改名称按钮和标签？

标签： javajavafx

Answer 1

您的代码有几个问题。

1. 数组索引从零开始，如有必要，应以 arrayLength - 1 结束。您的代码：answers[1][1] = "a) odp"; ... answers[1][4] = "d) odp";. 它应该是什么：answers[0][0] = "a) odp"; ... answers[0][3] = "d) odp";
2. 初始化控制器应该在控制器的初始化方法中完成。

下面的示例代码：

主要的：

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

/**
 *
 * @author blj0011
 */
public class JavaFXApplication226 extends Application
{

    @Override
    public void start(Stage stage) throws Exception
    {
        Parent root = FXMLLoader.load(getClass().getResource("Controller/Quiz.fxml"));

        Scene scene = new Scene(root);

        stage.setScene(scene);
        stage.show();
    }

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args)
    {
        launch(args);
    }

}

控制器：

import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import java.util.ResourceBundle;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.RadioButton;

/**
 *
 * @author blj0011
 */
public class FXMLDocumentController implements Initializable
{

    @FXML
    private Label questionLabel;
    @FXML
    private RadioButton answer_btn1;
    @FXML
    private RadioButton answer_btn2;
    @FXML
    private RadioButton answer_btn3;
    @FXML
    private RadioButton answer_btn4;
    @FXML
    private Button nextBtn;

    @Override
    public void initialize(URL url, ResourceBundle rb)
    {
        // TODO
        List<String> questions = new ArrayList();

        questions.add("pytanie1");
        questions.add("pytanie2");
        questions.add("pytanie3");
        questions.add("pytanie4");
        questions.add("pytanie5");
        questions.add("pytanie6");
        questions.add("pytanie7");
        questions.add("pytanie8");
        questions.add("pytanie9");
        questions.add("pytanie10");

        String[][] answers = new String[1][4];
        answers[0][0] = "a) odp";
        answers[0][1] = "b) odp";
        answers[0][2] = "c) odp";
        answers[0][3] = "d) odp";

        questionLabel.setText("");

        questionLabel.setText(questionLabel.getText() + answers[0][0]);
        answer_btn1.setText("aaa");
    }

}

FXML

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

<?import javafx.scene.control.Button?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.control.RadioButton?>
<?import javafx.scene.layout.AnchorPane?>

<AnchorPane id="AnchorPane" prefHeight="200" prefWidth="320" xmlns="http://javafx.com/javafx/8.0.141" xmlns:fx="http://javafx.com/fxml/1" fx:controller="javafxapplication226.FXMLDocumentController">
    <children>
        <Button fx:id="nextBtn" layoutX="118.0" layoutY="161.0" text="Click Me!" />
        <Label fx:id="questionLabel" layoutX="124.0" layoutY="36.0" minHeight="16" minWidth="69" />
      <RadioButton fx:id="answer_btn1" layoutX="47.0" layoutY="92.0" mnemonicParsing="false" text="RadioButton" />
      <RadioButton fx:id="answer_btn2" layoutX="193.0" layoutY="92.0" mnemonicParsing="false" text="RadioButton" />
      <RadioButton fx:id="answer_btn3" layoutX="47.0" layoutY="128.0" mnemonicParsing="false" text="RadioButton" />
      <RadioButton fx:id="answer_btn4" layoutX="183.0" layoutY="128.0" mnemonicParsing="false" text="RadioButton" />
    </children>
</AnchorPane>

我假设您的项目结构在您的代码中如下所示。