JavaFX TableView CheckBoxTableCell,带有布尔值而不是SimpleBooleanProperty

Question

我想知道如何在没有ObservableProperty的情况下使用CheckBoxTableCell.我正在使用一个简单的布尔值,因为我想将数据序列化到我的DerbyDB.

肯定会有可能创建一个SimpleBooleanProperty并用它来@Transient包围它并将它包装在我的正常情况下boolean active.

我的布尔值显示正确,但在单击Tableview中的Checkbox后,我无法存储新值.

private void setupColActive() {
    colActive.setCellValueFactory(new PropertyValueFactory<UserVillage, Boolean>("active"));
    colActive.setCellFactory(CheckBoxTableCell.forTableColumn(colActive));       
    colActive.setEditable(true);
}

我已经尝试过colActive.setOnEditCancel,colActive.setOnEditCommit并且colActive.setOnEditStart与打印大纲相结合,但我无法捕获新值来存储它.我想找到一种方法让它工作而不包装成@Transient SimpleBooleanProperty active.

Answer 1

序列化问题不会阻止您在模型类中使用JavaFX属性UserVillage.我建议使用这些属性,只需通过定义readObject和writeObject方法自定义序列化机制.这是一个像这样定义的类的演示:

public class Item implements Serializable {
    private StringProperty name ;
    private IntegerProperty value ;
    private BooleanProperty active ;

    public Item(String name, int value, boolean active) {
        this.name = new SimpleStringProperty(name) ;
        this.value = new SimpleIntegerProperty(value);
        this.active = new SimpleBooleanProperty(active);
    }


    public final StringProperty nameProperty() {
        return this.name;
    }
    public final java.lang.String getName() {
        return this.nameProperty().get();
    }
    public final void setName(final java.lang.String name) {
        this.nameProperty().set(name);
    }
    public final IntegerProperty valueProperty() {
        return this.value;
    }
    public final int getValue() {
        return this.valueProperty().get();
    }
    public final void setValue(final int value) {
        this.valueProperty().set(value);
    }
    public final BooleanProperty activeProperty() {
        return this.active;
    }
    public final boolean isActive() {
        return this.activeProperty().get();
    }
    public final void setActive(final boolean active) {
        this.activeProperty().set(active);
    }

    private void writeObject(ObjectOutputStream out) throws IOException {
        out.writeObject(getName());
        out.writeInt(getValue());
        out.writeBoolean(isActive());
    }

    private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
        this.name = new SimpleStringProperty((String)in.readObject());
        this.value = new SimpleIntegerProperty(in.readInt());
        this.active = new SimpleBooleanProperty(in.readBoolean());
    }

    // Quick test:
    public static void main(String[] args) throws IOException, ClassNotFoundException {
        Item testItem = new Item("Item", 42, true);
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        ObjectOutputStream oos = new ObjectOutputStream(out);
        oos.writeObject(testItem);
        oos.close();
        byte[] bytes = out.toByteArray();

        ObjectInputStream in = new ObjectInputStream(new ByteArrayInputStream(bytes));
        Item result = (Item) in.readObject();
        System.out.println(result.getName());
        System.out.println(result.getValue());
        System.out.println(result.isActive());
    }
}

使用这种方法,CheckBoxTableCell将自动绑定到由...返回的属性PropertyValueFactory.

另一种方法是创建一个BooleanProperty专门用于绑定到复选框选中状态的目的.请注意,根据Javadocs,因为CheckBoxTableCell永远不会进入或离开编辑状态,所以onEditCommit永远不会调用编辑回调等:

请注意,CheckBoxTableCell呈现CheckBox'live',这意味着CheckBox始终是交互式的,可以由用户直接切换.这意味着单元格不必进入其编辑状态(通常是用户双击单元格).这样的副作用是不会调用通常的编辑回调(例如编辑提交).如果希望收到更改通知,建议直接观察CheckBox操作的布尔属性.

这是使用这种技术的演示.同样,我并不真的推荐这种方法,因为你最终创建了一堆BooleanProperty很快就有资格进行垃圾收集的s.目标方法是让模型使用JavaFX属性.

import java.util.stream.IntStream;

import javafx.application.Application;
import javafx.beans.property.BooleanProperty;
import javafx.beans.property.SimpleBooleanProperty;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.cell.CheckBoxTableCell;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;

public class TableViewCheckBoxTest extends Application {

    @Override
    public void start(Stage primaryStage) {
        TableView<Item> table = new TableView<>();
        table.setEditable(true);
        table.getColumns().add(createColumn("Name", "name"));
        table.getColumns().add(createColumn("Value", "value"));

        TableColumn<Item, Boolean> activeCol = createColumn("Active", "active");
        table.getColumns().add(activeCol);

        activeCol.setCellFactory(col -> {
            CheckBoxTableCell<Item, Boolean> cell = new CheckBoxTableCell<>(index -> {
                BooleanProperty active = new SimpleBooleanProperty(table.getItems().get(index).isActive());
                active.addListener((obs, wasActive, isNowActive) -> {
                    Item item = table.getItems().get(index);
                    item.setActive(isNowActive);
                });
                return active ;
            });
            return cell ;
        });

        Button listActiveButton = new Button("List active");
        listActiveButton.setOnAction(e -> 
            table.getItems().stream()
                .filter(Item::isActive)
                .map(Item::getName)
                .forEach(System.out::println));

        IntStream.rangeClosed(1, 100)
            .mapToObj(i -> new Item("Item "+i, i, false))
            .forEach(table.getItems()::add);

        BorderPane root = new BorderPane(table, null, null, listActiveButton, null) ;
        BorderPane.setAlignment(listActiveButton, Pos.CENTER);
        BorderPane.setMargin(listActiveButton, new Insets(10));

        Scene scene = new Scene(root, 800, 600);
        primaryStage.setScene(scene);
        primaryStage.show();
    }

    private <S,T> TableColumn<S,T> createColumn(String title, String propertyName) {
        TableColumn<S,T> col = new TableColumn<>(title);
        col.setCellValueFactory(new PropertyValueFactory<>(propertyName));
        return col;
    }

    public static class Item implements Serializable {

        private String name ;
        private int value ;
        private boolean active ;

        public Item(String name, int value, boolean active) {
            this.name = name ;
            this.value = value ;
            this.active = active ;
        }

        public String getName() {
            return name;
        }

        public void setName(String name) {
            this.name = name;
        }

        public int getValue() {
            return value;
        }

        public void setValue(int value) {
            this.value = value;
        }

        public boolean isActive() {
            return active;
        }

        public void setActive(boolean active) {
            this.active = active;
        }

    }

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