JavaFX弹窗与主界面通信：实现数据回传与UI更新

package org.example;

import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.scene.control.TextField;
import javafx.stage.Stage;
import javafx.beans.property.StringProperty; // 导入 StringProperty
import javafx.beans.property.SimpleStringProperty; // 导入 SimpleStringProperty

import java.io.IOException;

public class SecondaryController {

    @FXML
    TextField textField;

    public Stage stage;

    // 定义一个私有的 StringProperty 来存储文本
    private final StringProperty text = new SimpleStringProperty();

    // 提供一个公共方法来获取这个属性，以便其他控制器可以绑定到它
    public StringProperty textProperty() {
        return text;
    }

    @SuppressWarnings("unused")
    public void writeToOwner(ActionEvent event) throws IOException {
        // 当用户提交时，更新 textProperty 的值
        text.set(textField.getText());
        // 关闭当前弹窗
        stage.close();
    }
}

package org.example;

import java.io.IOException;

import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.stage.Modality;
import javafx.stage.Stage;

public class PrimaryController {

    @FXML
    Label label;

    @SuppressWarnings("unused")
    public void login(ActionEvent event) throws IOException{
        FXMLLoader loader = new FXMLLoader(getClass().getResource("secondary.fxml"));
        Parent root = loader.load();

        SecondaryController secondaryController = loader.getController();
        secondaryController.stage = new Stage();
        secondaryController.stage.initModality(Modality.APPLICATION_MODAL);
        secondaryController.stage.initOwner(App.stage);

        // 关键步骤：将主界面的 label 的 textProperty 绑定到 SecondaryController 的 textProperty
        // 这样，当 SecondaryController 的 textProperty 改变时，label 也会自动更新
        label.textProperty().bind(secondaryController.textProperty());

        Scene scene = new Scene(root);
        secondaryController.stage.setScene(scene);
        secondaryController.stage.show();
    }

    // displayMessage 方法在此场景下不再需要，因为我们使用了数据绑定
    // public void displayMessage(String message){
    //     label.setText(message);
    // }
}

package org.example;

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

import java.util.Objects;

public class App extends Application {

    public static Stage stage;

    @Override
    public void start(Stage primaryStage) throws Exception {
        Parent root = FXMLLoader.load(Objects.requireNonNull(getClass().getResource("primary.fxml")));
        Scene scene = new Scene(root);
        stage = new Stage();
        stage.setScene(scene);
        stage.show();
    }

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

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

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

<AnchorPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="400.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/19" xmlns:fx="http://javafx.com/fxml/1" fx:controller="org.example.PrimaryController">
   <children>
      <Button layoutX="270.0" layoutY="230.0" mnemonicParsing="false" onAction="#login" text="Login" />
      <Label fx:id="label" layoutX="280.0" layoutY="191.0" />
   </children>
</AnchorPane>

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

<?import javafx.scene.control.TextField?>
<?import javafx.scene.layout.AnchorPane?>

<AnchorPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="400.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/19" xmlns:fx="http://javafx.com/fxml/1" fx:controller="org.example.SecondaryController">
   <children>
      <TextField fx:id="textField" layoutX="219.0" layoutY="187.0" onAction="#writeToOwner" />
   </children>
</AnchorPane>