访问JavaFx TableView/TableColumn中的嵌套属性 [英] Accessing nested properties in JavaFx TableView / TableColumn

问题描述

我有一个TableView，并且按如下方式访问列表对象的属性.这样就可以了.

I havea TableView, and I access properties of the list's objects as follows. This works just fine.

    <TableColumn fx:id="dateColumn" editable="false" prefWidth="135.0" text="Date">
        <cellValueFactory>
            <PropertyValueFactory property="date" />
        </cellValueFactory>
    </TableColumn>

但是，我想访问对象的嵌套属性，例如:

However, I'd like to access a nested property of the object, for example:

        <TableColumn prefWidth="100.0" text="Course">
            <cellValueFactory>
                <PropertyValueFactory property="house.bathroom"/>
            </cellValueFactory>
        </TableColumn>

其中我的列表对象有一个getHouse()，而House有一个getBathroom().不幸的是，这是行不通的.我尝试了一些拼写变化，但没有运气.

where my list object has a getHouse(), and House has a getBathroom(). Unfortunately, this doesn't work. I've tried a few spelling variations, but no luck.

推荐答案

我不相信您可以通过FXML来做到这一点(尽管我可能错了).

I don't believe you can do this via FXML (though I could be wrong).

假设您使用的是正确的JavaFX属性，则只需在控制器中设置自己的CellValueFactory即可，如下所示:

Assuming you're using proper JavaFX properties, you'd just setup your own CellValueFactory in the controller like so:

bathroomColumn.setCellValueFactory(tf -> tf.getValue().getHouse().bathroomProperty());

由于尚不清楚您要在浴室列中显示什么，因此将返回BathroomProperty.

Since it's unclear what you want to display in the bathroom column, this would return the BathroomProperty.

但是，如果您想在Bathroom对象的内中返回属性，则只需调用getBathroom().yourProperty():

If, however, you wanted to return a property within the Bathroom object, you'd simply call getBathroom().yourProperty() as well:

bathroomColumn.setCellValueFactory(tf -> tf.getValue().getHouse().getBathroom().myStringProperty());

---

也许一个例子可能有助于说明这一概念:

---

Perhaps an example might help to demonstrate the concept:

import javafx.application.Application;
import javafx.beans.property.ObjectProperty;
import javafx.beans.property.SimpleObjectProperty;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

public class TableViewValues extends Application {

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

    @Override
    public void start(Stage primaryStage) {

        // Simple Interface
        VBox root = new VBox(10);
        root.setAlignment(Pos.CENTER);
        root.setPadding(new Insets(10));

        // Simple TableView
        TableView<Person> personTableView = new TableView<>();
        TableColumn<Person, String> colName = new TableColumn<>("Name");
        TableColumn<Person, String> colCar = new TableColumn<>("Car");

        // Setup the CellValueFactories
        colName.setCellValueFactory(tf -> tf.getValue().nameProperty());
        colCar.setCellValueFactory(tf -> tf.getValue().getCar().modelProperty());

        personTableView.getColumns().addAll(colName, colCar);

        root.getChildren().add(personTableView);

        // Sample Data
        personTableView.getItems().addAll(
                new Person("Jack", new Car("Accord")),
                new Person("John", new Car("Mustang")),
                new Person("Sally", new Car("Yugo"))
        );

        // Show the stage
        primaryStage.setScene(new Scene(root));
        primaryStage.setTitle("Sample");
        primaryStage.show();
    }
}

class Person {

    private final StringProperty name = new SimpleStringProperty();
    private final ObjectProperty<Car> car = new SimpleObjectProperty<>();

    public Person(String name, Car car) {
        this.name.set(name);
        this.car.set(car);
    }

    public String getName() {
        return name.get();
    }

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

    public StringProperty nameProperty() {
        return name;
    }

    public Car getCar() {
        return car.get();
    }

    public void setCar(Car car) {
        this.car.set(car);
    }

    public ObjectProperty<Car> carProperty() {
        return car;
    }
}

class Car {
    private final StringProperty model = new SimpleStringProperty();

    public Car(String model) {
        this.model.set(model);
    }

    public String getModel() {
        return model.get();
    }

    public void setModel(String model) {
        this.model.set(model);
    }

    public StringProperty modelProperty() {
        return model;
    }
}

结果:

如果您使用的是普通Java Bean，则过程类似.但是，您无需在数据模型类中将CellValueProperty设置为Property，而是创建一个新的内联StringProperty并将其传递给您所需的bean值.

If you're using plain Java beans, the process is similar. But instead of setting the CellValueProperty to a Property within your data model classes, you'd create a new StringProperty inline and pass it the bean value you need.

因此，在上面的Car示例中，您将改为执行以下操作:

So, in the Car example above, you'd do this instead:

colName.setCellValueFactory(tf -> new SimpleStringProperty(tf.getValue().getName()));
colCar.setCellValueFactory(tf -> new SimpleStringProperty(tf.getValue().getCar().getModel()));

侧面注释::您在上面看到的tf只是我用来引用

Side Note: The tf you see referenced above is just a variable I use to refer to the CellDataFeatures object in Java which we can use to get a reference to that row's data model object (using the getValue() method). Perhaps cdf would be a better choice, but habits are hard to break.

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