组合框的标签未格式化

Question

我想创建一个显示为组合框的组列表:

import java.util.List;
import javafx.application.Application;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.scene.Scene;
import javafx.scene.control.ComboBox;
import javafx.scene.control.ListCell;
import javafx.scene.control.ListView;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;
import javafx.util.Callback;

public class Listobject extends Application
{

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

    @Override
    public void start(Stage stage)
    {

        // Insert Some data
        ListGroupsObj ob = ListGroupsObj.newInstance().groupId(12).groupName("Test");
        ListGroupsObj osb = ListGroupsObj.newInstance().groupId(13).groupName("Test2");

        final ComboBox<ListGroupsObj> listGroups = new ComboBox();

        listGroups.setButtonCell(new GroupListCell());
        listGroups.setCellFactory(new Callback<ListView<ListGroupsObj>, ListCell<ListGroupsObj>>()
        {
            @Override
            public ListCell<ListGroupsObj> call(ListView<ListGroupsObj> p)
            {
                return new GroupListCell();
            }
        });

        listGroups.setEditable(true);

        listGroups.getItems().addAll(ob, osb);
        listGroups.setValue(ob);

        // Display the selected Group
        listGroups.getSelectionModel().selectedItemProperty().addListener(new ChangeListener<ListGroupsObj>()
        {

            @Override
            public void changed(ObservableValue<? extends ListGroupsObj> arg0, ListGroupsObj arg1, ListGroupsObj arg2)
            {
                if (arg2 != null)
                {
                    System.out.println("Selected Group: " + arg1.getGroupId() + " - " + arg2.getGroupName());
                }
            }
        });

        final StackPane layout = new StackPane();
        layout.getChildren().add(listGroups);
        layout.setStyle("-fx-background-color: cornsilk; -fx-padding: 15;");
        stage.setScene(new Scene(layout));
        stage.show();
    }

    class GroupListCell extends ListCell<ListGroupsObj>
    {
        @Override
        protected void updateItem(ListGroupsObj item, boolean empty)
        {
            super.updateItem(item, empty);
            if (item != null)
            {
                setText(item.getGroupId() + " - " + item.getGroupName());
            }
        }
    }

    private List<ListGroupsObj> listGroups;

    public static class ListGroupsObj
    {

        private int groupId;
        private String groupName;

        public static ListGroupsObj newInstance()
        {
            return new ListGroupsObj();
        }

        public ListGroupsObj()
        {
        }

        public ListGroupsObj groupId(int groupId)
        {
            this.groupId = groupId;
            return this;
        }

        public ListGroupsObj groupName(String groupName)
        {
            this.groupName = groupName;
            return this;
        }

        public int getGroupId()
        {
            return groupId;
        }

        public String getGroupName()
        {
            return groupName;
        }

        //        @Override
//        public String toString()
//        {
//            return serverName;
//        }
    }
}

当我添加list groups . set editable(true)；默认选定组的标签不可读。你能帮我解决这个问题吗？另外，你能告诉我如何优化这个代码，使之易于使用吗？

Answer 1

为组合框提供转换器，以便从字符串转换为列表组Obj类型并返回。