javafx StringConverter最后一个对象 [英] javafx StringConverter Last Object

问题描述

我在创建可编辑的ListView时遇到一些问题。

i have a little problem for creating an editable ListView.

所以我有一个带有两个字段的City Class： id 和 name ，我已经从数据库中创建了一个ObservableList，并将它分配给我的ListView，我创建了我的cellFactory：

so i have a City Class with two field : id and name, i have created a ObservableList of cities from a database and assigned it to my ListView, and i have created my cellFactory :

@DatabaseTable(tableName = "city")
public class City {

    @DatabaseField(generatedId = true)
    private int id;

    @DatabaseField
    private String name;

    public City() {}
}

---

---

citiesList.setCellFactory(new Callback<ListView<City>, ListCell<City>>() {

            @Override
            public ListCell<City> call(ListView<City> param) {

                ListCell<City> cells = new TextFieldListCell<>(new StringConverter<City>() {

                    @Override
                    public String toString(City object) {
                        return object.getName().trim();
                    }

                    @Override
                    public City fromString(String string) {
                        // how to modify the object that was in the cell???
                        return null;
                    }
                });

                return cells;
            }
        });

我想知道是否可以获取单元格中当前值的引用（City）当 fromString 被调用时

I want to know if its possible to get a reference of the current value in the cell(City) when fromString is called

我想这样做是为了允许用户更改城市名称而不必更改其ID字段。

i want to do that to allow user to change City name without having to change its Id field.

推荐答案

如果先创建单元格，然后创建转换器，则可以引用单元格。转换器中的getItem（）。以下似乎有效：

If you create the cell first, then create the converter, you can reference cell.getItem() in the converter. The following seems to work:

citiesList.setCellFactory(lv -> {
    TextFieldListCell<City> cell = new TextFieldListCell<City>();
    StringConverter<City> converter = new StringConverter<City>() {

        @Override
        public String toString(City city) {
            return city.getName();
        }

        @Override
        public City fromString(String string) {
            City city = cell.getItem();
            if (city == null) {
                City newCity = new City();
                newCity.setName(string);
                return newCity;
            } else {
                city.setName(string);
                return city ;
            }
        }

    };

    cell.setConverter(converter);

    return cell ;
});

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