我无法将数据从一个屏幕中的表格装入另一个屏幕中的文本字段。 我有两个“ 第一” 类别, 包含一个文本框和一个按钮。 按下按钮时, 打开第二个窗口, 包含一个数值表。 当用户双击一行时, 第二列的值应该插入到第一“ 屏幕” 的文本框中。 两个类别的代码都附在后面。 感谢您期待 。

import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.TextField;
import javafx.scene.layout.GridPane;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;

public class FirstClass extends Application {
public static void main(String[] args) {
    launch(args);
}

@Override
public void start(final Stage primaryStage) {
    primaryStage.setTitle("First Class");

    GridPane gridpane = new GridPane();
    gridpane.setPadding(new Insets(5));
    gridpane.setHgap(5);
    gridpane.setVgap(5);

    final TextField userNameFld = new TextField();
    gridpane.add(userNameFld, 1, 1);
    Button btn = new Button();
    btn.setText("Show Table");
    gridpane.add(btn, 1, 3);

    btn.setOnAction(new EventHandler<ActionEvent>() {

        @Override
        public void handle(ActionEvent event) {
            String a = TableClass.showDialog(primaryStage, true, "Table Window" );
            userNameFld.setText(a);
        }
    });

    StackPane root = new StackPane();

    Scene scene =new Scene(root, 300, 250);

    root.getChildren().addAll(gridpane);
    primaryStage.setScene(scene);
    primaryStage.show();
 }
}







import javafx.beans.property.SimpleStringProperty;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.event.EventHandler;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.GridPane;
import javafx.scene.layout.StackPane;
import javafx.stage.Modality;
import javafx.stage.Stage;

public class TableClass extends Stage {

private static TableClass dialog;
private static String value = "";


public static class Person {
    private final SimpleStringProperty firstName;
    private final SimpleStringProperty lastName;


    private Person(String fName, String lName) {
        this.firstName = new SimpleStringProperty(fName);
        this.lastName = new SimpleStringProperty(lName);
    }

    public String getFirstName() {
        return firstName.get();
    }
    public void setFirstName(String fName) {
        firstName.set(fName);
    }

    public String getLastName() {
        return lastName.get();
    }
    public void setLastName(String fName) {
        lastName.set(fName);
    }
}


 private TableView<Person> table = new TableView<Person>();
    private final ObservableList<Person> data = 
        FXCollections.observableArrayList(
            new Person("JACK", "BROWN"),
            new Person("JOHN", "VIANNEYS"),
            new Person("MICHAEL", "NELSON"),
            new Person("WILLIAM", " CAREY")
        );


public TableClass(Stage owner, boolean modality, String title) {
    super();
    initOwner(owner);
    Modality m = modality ? Modality.APPLICATION_MODAL : Modality.NONE;
    initModality(m);
    setOpacity(1);
    setTitle(title);

    StackPane root = new StackPane();

    Scene scene = new Scene(root, 750, 750);

    setScene(scene);
    GridPane gridpane = new GridPane();
    gridpane.setPadding(new Insets(5));
    gridpane.setHgap(5);
    gridpane.setVgap(5);


    TableColumn firstNameCol = new TableColumn("First Name");
    firstNameCol.setMinWidth(100);
    firstNameCol.setCellValueFactory(
    new PropertyValueFactory<Person,String>("firstName")
    );

    TableColumn lastNameCol = new TableColumn("Last Name");
    lastNameCol.setMinWidth(200);
    lastNameCol.setCellValueFactory(
    new PropertyValueFactory<Person,String>("lastName")
    );



    table.setItems(data);
    table.getColumns().addAll(firstNameCol, lastNameCol);



    table.setOnMouseClicked(new EventHandler<MouseEvent>() {

           public void handle(MouseEvent me) {

                   if (me.getClickCount() >= 2) {
                       String  srr = table.getItems().get    (table.getSelectionModel().getSelectedIndex()).getLastName();
                       value = srr;
                       dialog.hide();
                      }
               }
        });


    gridpane.add(table, 1, 5,1,20 );
    root.getChildren().add(gridpane);
    }


public static String showDialog(Stage stg, Boolean a , String title){
      dialog = new TableClass( stg,a, title);
      dialog.show();
      return value;
  }
 }