将LongProperty绑定到ListProperty的内部更改

import javafx.beans.property.ListProperty;
import javafx.beans.property.SimpleListProperty;
import javafx.beans.property.SimpleLongProperty;
import javafx.beans.property.LongProperty;
import javafx.collections.FXCollections;
import javafx.collections.ListChangeListener;

public class Main {
    public static void main(String[] args) {
        ListProperty<String> listProperty = new SimpleListProperty<>(FXCollections.observableArrayList());
        LongProperty sizeProperty = new SimpleLongProperty();

        listProperty.addListener((ListChangeListener<String>) change -> {
            sizeProperty.set(listProperty.size());
        });

        listProperty.add("Item 1");
        listProperty.add("Item 2");
        listProperty.add("Item 3");

        System.out.println("List size: " + sizeProperty.get()); // 输出: List size: 3
    }
}