JavaFx - 如何在TableView中显示SimpleStringProperty值

Question

我正在忙着完成一个教程并且坚持一点.

基本上在表视图中从Person类型的ObservableList中启动新场景和显示值.

person类由3个SimpleStringProperty的firsName,lastName和email组成.

但是当我运行应用程序时,它似乎在表中显示SimpleStringProperty [StringProperty [value:actualvalue]]的值,而不是SimpleStringProperty的值.如果我更改Person的类getFirstName方法以返回String firstName.get(),那么它会在表中正确显示值.

我应该使用SimpleStringProperty还是像String这样的普通对象？

人类

package co.za.chrispie.addressBook;

import javafx.beans.property.SimpleStringProperty;

public class Person {

private SimpleStringProperty firstName;
private SimpleStringProperty lastName;
private SimpleStringProperty email;

public Person(final String firstName, final String lastName, final String email) {
    this.firstName = new SimpleStringProperty(firstName);
    this.lastName = new SimpleStringProperty(lastName);
    this.email = new SimpleStringProperty(email);
}

public String getFirstName() {
    return firstName.get(); //Changes this method to return a String
}

public SimpleStringProperty getLastName() {
    return lastName;
}

public SimpleStringProperty getEmail() {
    return email;
}

}

Controller类

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package co.za.chrispie.addressBook;

import java.net.URL;
import java.util.ResourceBundle;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.cell.PropertyValueFactory;

public class OracleAddressBookController implements Initializable {

@FXML
TableView<Person> table;
@FXML
TableColumn<Person, String> colFirstName;
@FXML
TableColumn<Person, String> colLastName;
@FXML
TableColumn<Person, String> colEmail;

final ObservableList<Person> data = FXCollections.observableArrayList(
    new Person("Jaco", "Pieters", "jp@me.co.za"),
    new Person("Chrispie", "Pieters", "chrispie@me.co.za")
);

@Override
public void initialize(URL url, ResourceBundle rb) {
    assert colFirstName != null : "fx:id=\"colFirstName\" was not injected: check your FXML file 'OracleAddressBook.fxml'.";
    assert colLastName != null : "fx:id=\"colLastName\" was not injected: check your FXML file 'OracleAddressBook.fxml'.";
    assert colEmail != null : "fx:id=\"colEmail\" was not injected: check your FXML file 'OracleAddressBook.fxml'.";
    configureTable();
}    

private void configureTable() {
    colFirstName.setCellValueFactory(new PropertyValueFactory<Person, String>("firstName"));
    colLastName.setCellValueFactory(new PropertyValueFactory<Person, String>("lastName"));
    colEmail.setCellValueFactory(new PropertyValueFactory<Person, String>("email"));

    table.setColumnResizePolicy(TableView.CONSTRAINED_RESIZE_POLICY);

    table.setItems(data);
    assert table.getItems() == data;
}
}

和前端FXML

<?xml version="1.0" encoding="UTF-8"?>

<?import java.lang.*?>
<?import java.net.*?>
<?import java.util.*?>
<?import javafx.scene.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>

<AnchorPane id="AnchorPane" prefHeight="500.0" prefWidth="600.0"    styleClass="mainFxmlClass" xmlns:fx="http://javafx.com/fxml"  fx:controller="co.za.chrispie.addressBook.OracleAddressBookController">
<children>
  <Label layoutX="14.0" layoutY="11.0" text="Address Book" />
  <TableView fx:id="table" layoutX="14.0" layoutY="35.0" prefHeight="451.0" prefWidth="572.0">
  <columns>
    <TableColumn prefWidth="75.0" text="First Name" fx:id="colFirstName" />
    <TableColumn prefWidth="75.0" text="Last Name" fx:id="colLastName" />
    <TableColumn prefWidth="75.0" text="Email" fx:id="colEmail" />
  </columns>
</TableView>
 </children>
  <stylesheets>
   <URL value="@oracleaddressbook.css" />
 </stylesheets>
</AnchorPane>

Answer 1

您需要将属性getter的名称更改为nameProperty(),其中name是您的属性.所以你会有firstNameProperty()和emailProperty().

getName() 有效,但该表不会观察属性的更改.

PropertyValueFactory的doc解释了这个主题:

在此示例中,"firstName"字符串用作Person类类型中假定的firstNameProperty()方法的引用(这是TableView项列表的类类型).此外,此方法必须返回Property实例.如果找到满足这些要求的方法,则使用此ObservableValue填充TableCell.此外,TableView将自动向返回的值添加一个观察者,以便TableView将观察到触发的任何更改,从而导致单元格立即更新.

如果不存在与此模式匹配的方法,则会尝试调用get()或is()(即上例中的getFirstName()或isFirstName()).如果存在与此模式匹配的方法,则此方法返回的值将包装在ReadOnlyObjectWrapper中并返回到TableCell.但是,在这种情况下,这意味着TableCell将无法观察ObservableValue的更改(如上面第一种方法中的情况).