JavaFX RadioButton 的方法 "isSelected()"不工作/或未正确实现

Question

我正在尝试设置显示内容的变化与所选 RadioButton 的值相关。问题是它对按钮的选择没有反应。 也许我的实现有问题。

当我设置一个 onAction 事件时它有时会起作用，但这会引入一些不同的问题，因此我想找到一个解决方案。

        Label title = new Label("USER REGISTRATION");
        title.setId("title");

        Label pickUserLabel = new Label("User type");
        pickUserLabel.getStyleClass().add("labels");

        RadioButton pickStudent = new RadioButton("Student");
        RadioButton pickProfessor = new RadioButton("Professor");

        /*
         * Selection of user type -> adds additional fields if needed
         */
        ToggleGroup userTypeGroup = new ToggleGroup();
        pickStudent.setToggleGroup(userTypeGroup);
        pickStudent.setSelected(true);
        pickProfessor.setToggleGroup(userTypeGroup);
        pickStudent.getStyleClass().add("radio");
        pickProfessor.getStyleClass().add("radio");

        /*
         * text fields and labels below are used whenever additional ones are needed
         */
        TextField textField1 = new TextField();
        TextField textField2 = new TextField();
        TextField textField3 = new TextField();

        Label label1 = new Label();
        Label label2 = new Label();
        Label label3 = new Label();

        ChoiceBox<AcademicTitles> academicTitleChoice = new ChoiceBox<AcademicTitles>();

        academicTitleChoice.getSelectionModel().selectedItemProperty().addListener((v, oldValue, newValue) -> System.out.println(newValue));

        if(pickStudent.isSelected()) {
            label1.setText("Email");
            label1.getStyleClass().add("labels");
            textField1.setPromptText("E-mail");

            label2.setText("Phone Number");
            label2.getStyleClass().add("labels");
            textField2.setPromptText("Phone number");

            label3.setText("Recordbook Number");
            label3.getStyleClass().add("labels");
            textField3.setPromptText("Recordbook number");

            academicTitleChoice.hide();
        };

        if(pickProfessor.isSelected()) {
            label1.setText("Email");
            label1.getStyleClass().add("labels");
            textField1.setPromptText("E-mail");

            layout.getChildren().remove(label2);
            layout.getChildren().remove(textField2);
            layout.getChildren().remove(label3);
            layout.getChildren().remove(textField3);

            academicTitleChoice.getItems().addAll(AcademicTitles.PROFESSOR, AcademicTitles.ASSOCIATE_PROFESSOR,
                                                  AcademicTitles.ASSISTANT_PROFESSOR, AcademicTitles.RESEARCH_PROFESSOR,
                                                  AcademicTitles.TEACHING_ASSISTANT);
            academicTitleChoice.setValue(AcademicTitles.PROFESSOR);
            academicTitleChoice.setMaxWidth(150);
            academicTitleChoice.setId("academicTitleChoice");
        };

        Separator separator = new Separator();

        /*
         * First Name
         */
        Label firstNameLabel = new Label("Enter First Name");
        firstNameLabel.getStyleClass().add("labels");
        TextField firstName = new TextField();
        firstName.setPromptText("First name");
        firstName.setMaxWidth(200);

        /*
         * Last Name
         */
        Label lastNameLabel = new Label("Enter Last Name");
        lastNameLabel.getStyleClass().add("labels");
        TextField lastName = new TextField();
        lastName.setPromptText("Last name");
        lastName.setMaxWidth(200);

        /*
         * Username
         */
        Label usernameLabel = new Label("Enter Username");
        usernameLabel.getStyleClass().add("labels");
        Label usernameInfo = new Label("(length must be >= 4)");
        usernameInfo.getStyleClass().add("info");
        TextField username = new TextField();
        username.setPromptText("Username");
        username.setMaxWidth(200);

        /*
         * Password
         */
        Label passwordLabel = new Label("Enter Password");
        passwordLabel.getStyleClass().add("labels");
        Label passwordInfo = new Label("(length must be >= 6)");
        passwordInfo.getStyleClass().add("info");
        PasswordField password = new PasswordField();
        password.setPromptText("Password");
        password.setMaxWidth(200);

        Button registrationButton = new Button("Register User");
        registrationButton.setOnAction(e -> register());

        GridPane.setConstraints(title, 0, 0);
        GridPane.setConstraints(pickUserLabel, 0, 1);
        GridPane.setConstraints(pickStudent, 0, 2);
        GridPane.setConstraints(pickProfessor, 0, 3);
        GridPane.setConstraints(separator, 0, 5);
        GridPane.setConstraints(firstNameLabel, 0, 6);
        GridPane.setConstraints(firstName, 1, 6);
        GridPane.setConstraints(lastNameLabel, 0, 7);
        GridPane.setConstraints(lastName, 1, 7);
        GridPane.setConstraints(academicTitleChoice, 2, 7);
        GridPane.setConstraints(usernameLabel, 0, 8);
        GridPane.setConstraints(username, 1, 8);
        GridPane.setConstraints(usernameInfo, 2, 8);
        GridPane.setConstraints(passwordLabel, 0, 9);
        GridPane.setConstraints(password, 1, 9);
        GridPane.setConstraints(passwordInfo, 2, 9);
        GridPane.setConstraints(label1, 0, 10);
        GridPane.setConstraints(textField1, 1, 10);
        GridPane.setConstraints(label2, 0, 11);
        GridPane.setConstraints(textField2, 1, 11);
        GridPane.setConstraints(label3, 0, 12);
        GridPane.setConstraints(textField3, 1, 12);
        GridPane.setConstraints(registrationButton, 1, 13);
        GridPane.setHalignment(registrationButton, HPos.RIGHT);

        layout.getChildren().addAll(title, pickUserLabel, pickStudent, pickProfessor, separator, firstNameLabel, firstName, lastNameLabel, lastName, usernameLabel, username, passwordLabel, password, passwordInfo, academicTitleChoice, label1, label2, textField2, label3, textField3, registrationButton);
        layout.setAlignment(Pos.CENTER);
        layout.setVgap(10);
        layout.setHgap(10);
        layout.setId("rightSide");
        layout.setPrefSize(620, 550);

        return layout;

结果应该是，如果选择 Professor RadioButton，字段会发生变化，Student 也是如此。

Answer 1

您的 if 语句仅在加载类/方法时调用一次。您需要“收听”RadioButton.selectedProperty 或 ToggleGroup.selectedToggleProperty 并采取相应行动。

这里是一个简单的例子，说明如何监听 ToggleGroup 并根据选择的 RadioButton 执行代码:

import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.RadioButton;
import javafx.scene.control.ToggleGroup;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

public class RadioButtonListener extends Application {

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

    @Override
    public void start(Stage primaryStage) {

        // Simple Interface
        VBox root = new VBox(10);
        root.setAlignment(Pos.CENTER);
        root.setPadding(new Insets(10));

        // Create the toggle group
        ToggleGroup group = new ToggleGroup();

        // Create two radio buttons
        RadioButton rdo1 = new RadioButton("One");
        RadioButton rdo2 = new RadioButton("Two");

        // Add them to the ToggleGroup
        group.getToggles().addAll(rdo1, rdo2);

        // Add a listener to the ToggleGroup to determine when a selection has changed
        group.selectedToggleProperty().addListener((observable, oldValue, newValue) -> {
            if (newValue.equals(rdo1)) {
                System.out.println("ONE selected");
            } else if (newValue.equals(rdo2)) {
                System.out.println("TWO selected");
            }
        });

        // Add the RadioButtons to the stage
        root.getChildren().addAll(rdo1, rdo2);

        // Show the stage
        primaryStage.setScene(new Scene(root));
        primaryStage.setTitle("Sample");
        primaryStage.show();
    }
}

---

您可以通过向每个 RadioButton 添加一个监听器来做类似的事情:

rdo1.selectedProperty().addListener((observable, oldValue, newValue) -> {
    if (newValue) {
        System.out.println("ONE Selected!");
    } else {
        System.out.println("ONE deselected!");
    }
});