将 Java FX 表单数据添加到 ArrayList

Question

In school i had the task to create a JavaFX form GUI in which I can write some Strings like name , eMail ...

First I should make a class Person in which the data fields are located.

And there should be a class AdressDB in which I create a list about Person

In the class GUI I should create a form that can be used to add "Persons" to the list. For example with a button.

"Create a class AdressDB . This class keeps a list of Person . Person holds typical data fields such as: eMail , Name , .... In the GUI class you implement a form that you can use to add "Persons" to the list."

I have already completed the form. Now my question: How can I add the data from the form to the ArrayList ?

import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.geometry.HPos;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.scene.layout.*;
import javafx.scene.text.Font;
import javafx.scene.text.FontWeight;
import javafx.stage.Stage;
import javafx.stage.Window;
import java.util.ArrayList;
import javafx.scene.text.Text;
import javafx.scene.text.*;

public class GUI extends Application {
    private TextField fieldName, fieldActor;
    @Override
    public void start(Stage primaryStage) throws Exception {
        primaryStage.setTitle("Registration Form JavaFX Application");

        GridPane gridPane = createRegistrationFormPane();
        addUIControls(gridPane);
        Scene scene = new Scene(gridPane, 800, 500);
        primaryStage.setScene(scene);
        primaryStage.show();

    }

    private GridPane createRegistrationFormPane() {
        // Instantiate a new Grid Pane
        GridPane gridPane = new GridPane();

        // Position the pane at the center of the screen, both vertically and horizontally
        gridPane.setAlignment(Pos.CENTER);

        // Set a padding of 20px on each side
        gridPane.setPadding(new Insets(40, 40, 40, 40));

        // Set the horizontal gap between columns
        gridPane.setHgap(10);

        // Set the vertical gap between rows
        gridPane.setVgap(10);

        // Add Column Constraints

        // columnOneConstraints will be applied to all the nodes placed in column one.
        ColumnConstraints columnOneConstraints = new ColumnConstraints(100, 100, Double.MAX_VALUE);
        columnOneConstraints.setHalignment(HPos.RIGHT);

        // columnTwoConstraints will be applied to all the nodes placed in column two.
        ColumnConstraints columnTwoConstrains = new ColumnConstraints(200,200, Double.MAX_VALUE);
        columnTwoConstrains.setHgrow(Priority.ALWAYS);

        gridPane.getColumnConstraints().addAll(columnOneConstraints, columnTwoConstrains);

        return gridPane;
    }

    private void addUIControls(GridPane gridPane) {

        Label headerLabel = new Label("Bitte geben sie Ihre Daten ein");
        headerLabel.setFont(Font.font("Arial", FontWeight.BOLD, 24));
        gridPane.add(headerLabel, 0,0,2,1);
        GridPane.setHalignment(headerLabel, HPos.CENTER);
        GridPane.setMargin(headerLabel, new Insets(20, 0,20,0));

        // Add Name Label
        Label nameLabel = new Label("Name : ");
        gridPane.add(nameLabel, 0,1);

        // Add Name Text Field
        TextField name = new TextField();
        name.setPrefHeight(40);
        gridPane.add(name, 1,1);

        // Add Email Label
        Label emailLabel = new Label("E-Mail: ");
        gridPane.add(emailLabel, 0, 2);

        // Add Email Text Field
        TextField email = new TextField();
        email.setPrefHeight(40);
        gridPane.add(email, 1, 2);

        // Add Birthday Label
        Label Geburtsdatum = new Label("Geburtsdatum : ");
        gridPane.add(Geburtsdatum, 0, 3);

        // Add Birhday Field
        TextField geburtsdatum = new TextField();
        geburtsdatum.setPrefHeight(40);
        gridPane.add(geburtsdatum, 1, 3);
        geburtsdatum.setText("Geburtsdatum");


        // Add Submit Button
        Button submitButton = new Button("Submit");
        submitButton.setPrefHeight(40);
        submitButton.setDefaultButton(true);
        submitButton.setPrefWidth(100);
        gridPane.add(submitButton, 0, 4, 2, 1);
        GridPane.setHalignment(submitButton, HPos.CENTER);
        GridPane.setMargin(submitButton, new Insets(20, 0,20,0));





        submitButton.setOnAction(new EventHandler<ActionEvent>() {
                @Override
                public void handle(ActionEvent event) {

        ;







                    if(name.getText().isEmpty()) {
                        showAlert(Alert.AlertType.ERROR, gridPane.getScene().getWindow(), "Form Error!", "Please enter your name");
                        return;
                    }
                    if(email.getText().isEmpty()) {
                        showAlert(Alert.AlertType.ERROR, gridPane.getScene().getWindow(), "Form Error!", "Please enter your email id");
                        return;
                    }
                    if(geburtsdatum.getText().isEmpty()) {
                        showAlert(Alert.AlertType.ERROR, gridPane.getScene().getWindow(), "Form Error!", "Please enter a password");
                        return;
                    }

                    showAlert(Alert.AlertType.CONFIRMATION, gridPane.getScene().getWindow(), "Wir haben ihre Daten erhalten!", "Vielen dank für ihr Vertrauen " + name.getText());





                }
            });

    }



        private void showAlert(Alert.AlertType alertType, Window owner, String title, String message) {
            Alert alert = new Alert(alertType);
            alert.setTitle(title);
            alert.setHeaderText(null);
            alert.setContentText(message);
            alert.initOwner(owner);
            alert.show();
        }





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


}

Answer 1

In the handle method of submitButton.setOnAction you need to read the fields to create a new Person. This new Person than can be added to the ArrayList.

As long as you implement the buttons setOnAction Method in the same method, where you define the TextFields, this works well. But as soon as you move the buttons setOnAction implementation to another method, you need to define the TextFields as class "variables" (Fields!) to access them.