JavaFX 中的 BigInteger 属性是什么？

Question

如何在 JavaFX 中将 BigInteger 用作属性，就像将 String 用作属性一样用作 SimpleStringProperty？

Answer 1

JavaFX 中没有 BigIntegerProperty（或任何 BigInteger 属性实现），但您可以将 ObjectProperty<T> 用作 ObjectProperty<BigInteger>:

ObjectProperty<BigInteger> bigIntProp = new SimpleObjectProperty<>();

这个属性存储了一个BigInteger实例，可以被监听和绑定。

例子

使用此类型的 Application，绑定到 TextArea:

的文本

public class Main extends Application {

    @Override
    public void start(Stage primaryStage) throws Exception {
        BorderPane root = new BorderPane();

        ObjectProperty<BigInteger> bigIntProp = new SimpleObjectProperty<>();
        bigIntProp.addListener((obs, oldval, newval) -> System.out.println(newval));

        TextArea ta = new TextArea();

        bigIntProp.bind(Bindings.createObjectBinding(() ->
                        (!ta.getText().isEmpty()) ? new BigInteger(ta.getText()) : BigInteger.ZERO
                , ta.textProperty()));
        root.setCenter(ta);

        primaryStage.setScene(new Scene(root, 300, 275));
        primaryStage.show();
    }

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

Answer 2

java中没有built-inBigInteger属性class像SimpleStringPropertyclass.

所以我为您创建了一个 SimpleBigInteger属性，它可以像那些 built-in 属性一样使用 classes。

import java.math.BigInteger;
import javafx.beans.property.SimpleObjectProperty;
/**
 * 
 * This class provides a full implementation of a {@link Property} wrapping an
 * arbitrary {@code BigInteger}.
 */
public class SimpleBigIntegerProperty extends SimpleObjectProperty<BigInteger>{

    private static final Object DEFAULT_BEAN = null;
    private static final String DEFAULT_NAME = "";

    private final Object bean;
    private final String name;
    /**
     * {@inheritDoc}
     */
    @Override
    public Object getBean() {
        return bean;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public String getName() {
        return name;
    }

    /**
     * The constructor of {@code BigIntegerProperty}
     */
    public SimpleBigIntegerProperty() {
        this(DEFAULT_BEAN, DEFAULT_NAME);
    }
    /**
     * The constructor of {@code BigIntegerProperty}
     * 
     * @param initialValue
     *            the initial value of the wrapped value
     */
    public SimpleBigIntegerProperty(BigInteger initialValue) {
        this(DEFAULT_BEAN, DEFAULT_NAME, initialValue);
    }

    /**
     * The constructor of {@code BigIntegerProperty}
     * 
     * @param bean
     *            the bean of this {@code BigIntegerProperty}
     * @param name
     *            the name of this {@code BigIntegerProperty}
     */
    public SimpleBigIntegerProperty(Object bean, String name) {
        this.bean = bean;
        this.name = (name == null) ? DEFAULT_NAME : name;
    }

    /**
     * The constructor of {@code BigIntegerProperty}
     * 
     * @param bean
     *            the bean of this {@code BigIntegerProperty}
     * @param name
     *            the name of this {@code BigIntegerProperty}
     * @param initialValue
     *            the initial value of the wrapped value
     */
    public SimpleBigIntegerProperty(Object bean, String name, BigInteger initialValue) {
        super(initialValue);
        this.bean = bean;
        this.name = (name == null) ? DEFAULT_NAME : name;
    }

}

示例 1：

一个简单的例子，

SimpleBigIntegerProperty bigInteger = new SimpleBigIntegerProperty(BigInteger.valueOf(123456789));
System.out.println(bigInteger.getValue());

示例 2： 以ObservableList为例，

private final ObservableList<Person> data = FXCollections.observableArrayList(
        new Person("Jon Skeet", BigInteger.valueOf(123456789)),
        new Person("Michael Brown", BigInteger.valueOf(987654321))
);

人 class（具有人名和 age-in-seconds 属性）在哪里，

public class Person {

    protected SimpleStringProperty personName;
    protected SimpleBigIntegerProperty ageInSeconds;

    public Person() {
        this.personName = null;
        this.ageInSeconds = null;
    }

    public Person(String person_name, BigInteger age_in_seconds) {
        this.personName = new SimpleStringProperty(person_name);
        this.ageInSeconds = new SimpleBigIntegerProperty(age_in_seconds);
    }

    public void setPersonName(String person_name) {
        this.personName = new SimpleStringProperty(person_name);
    }

    public void setAgeInSeconds(BigInteger age_in_seconds) {
        this.ageInSeconds = new SimpleBigIntegerProperty(age_in_seconds);
    }

    public String getPersonName() {
        return this.personName.getValue();
    }

    public BigInteger getAgeInSeconds() {
        return this.ageInSeconds.getValue();
    }
}

JavaFX 中的 BigInteger 属性是什么？

What is the BigInteger property in JavaFX?

java

javafx

properties

biginteger

javafx-8

JavaFX 中的 BigInteger 属性 是什么？

What is the BigInteger property in JavaFX?

java

javafx

properties

biginteger

javafx-8

JavaFX 中的 BigInteger 属性是什么？