代码之家 › 专栏 › 技术社区 › trashgod

连接具有StringConverter的滑块和微调器

spinner slider javafx swing java

trashgod · 技术社区 · 7 年前

对于数字输入,有时将模拟控件同步到文本显示很方便。在这个秋千上 example A JSpinner 和A JSlider 每一个都侦听更改事件,并且每一个都更新另一个的模型以进行匹配。类似的javafx程序,如下所示,连接 Spinner 和A Slider ,并且这些侦听器使控件保持协调:

slider.valueProperty().addListener((Observable o) -> {
    spinner.getValueFactory().setValue(slider.getValue());
});
spinner.valueProperty().addListener((Observable o) -> {
    slider.setValue((double) spinner.getValue());
});

不幸的是,当我添加 StringConverter 到旋转器的 SpinnerValueFactory ,重新显式设置初始值时,初始值未格式化,直到其中一个控件更改为deven, 之后添加转换器:

spinner.getValueFactory().setConverter(â¦);
spinner.getValueFactory().setValue(INITIAL_VALUE);

我哪里做错了?

import java.text.NumberFormat;
import javafx.application.Application;
import javafx.beans.Observable;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.Slider;
import javafx.scene.control.Spinner;
import javafx.scene.layout.GridPane;
import javafx.stage.Stage;
import javafx.util.converter.PercentageStringConverter;

/**
 * @see https://stackoverflow.com/a/6067986/230513
 */
public class SpinSlider extends Application {

    private static final double MIN = 0;
    private static final double MAX = 1;
    private static final double INITIAL_VALUE = 0.5;
    private static final double STEP_INCREMENT = 0.1;

    @Override
    public void start(Stage primaryStage) {
        primaryStage.setTitle("SpinSlider");
        Slider slider = new Slider(MIN, MAX, INITIAL_VALUE);
        slider.setBlockIncrement(STEP_INCREMENT);
        Spinner spinner = new Spinner(MIN, MAX, INITIAL_VALUE, STEP_INCREMENT);
        spinner.getValueFactory().setConverter(
            new PercentageStringConverter(NumberFormat.getPercentInstance()));
        spinner.getValueFactory().setValue(INITIAL_VALUE);
        slider.valueProperty().addListener((Observable o) -> {
            spinner.getValueFactory().setValue(slider.getValue());
        });
        spinner.valueProperty().addListener((Observable o) -> {
            slider.setValue((double) spinner.getValue());
        });
        GridPane root = new GridPane();
        root.addRow(0, slider, spinner);
        root.setPadding(new Insets(8, 8, 8, 8));
        root.setHgap(8);
        Scene scene = new Scene(root);
        primaryStage.setScene(scene);
        primaryStage.show();
    }

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

}

1 回复 | 直到 7 年前

trashgod 7 年前

你的 INITIAL_VALUE 首先用作 initialValue 微调器构造函数的参数。在内部,旋转器的混凝土 SpinnerValueFactory 是一个 DoubleSpinnerValueFactory 增加了 ChangeListener 对其 value 属性;当重新设置初始值时,该值实际上没有改变 . 有两种方法:

为构造函数指定不同的值,并在添加转换器后设置所需的值:

Spinner spinner = new Spinner(MIN, MAX, -42, STEP_INCREMENT);
spinner.getValueFactory().setConverter(â¦);
spinner.getValueFactory().setValue(INITIAL_VALUE);

构建一个 旋神经值工厂 使用所需的初始值并使用它构造微调器:

SpinnerValueFactory factory = new SpinnerValueFactory
    .DoubleSpinnerValueFactory(MIN, MAX, INITIAL_VALUE, STEP_INCREMENT);
factory.setConverter(â¦);
Spinner spinner = new Spinner(factory);

此外,下面的示例将两个侦听器替换为双向绑定,该绑定使用弱侦听器来允许对属性进行垃圾收集:

slider.valueProperty().bindBidirectional(
    spinner.getValueFactory().valueProperty());

简单地说,微调器和滑块可以相互控制。更常见的是,在控制由另一个模型持有的属性的过程中,每个模型都可以保持同步:

model.xProperty().bindBidirectional(slider.valueProperty());
model.xProperty().bindBidirectional(spinner.getValueFactory().valueProperty());

import java.text.NumberFormat;
import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.Slider;
import javafx.scene.control.Spinner;
import javafx.scene.control.SpinnerValueFactory;
import javafx.scene.layout.GridPane;
import javafx.stage.Stage;
import javafx.util.converter.PercentageStringConverter;

/**
 * @see https://stackoverflow.com/a/55427307/230513
 * @see https://stackoverflow.com/a/6067986/230513
 */
public class SpinSlider extends Application {

    private static final double MIN = 0;
    private static final double MAX = 1;
    private static final double INITIAL_VALUE = 0.5;
    private static final double STEP_INCREMENT = 0.1;

    @Override
    public void start(Stage primaryStage) {
        primaryStage.setTitle("SpinSlider");
        Slider slider = new Slider(MIN, MAX, INITIAL_VALUE);
        slider.setBlockIncrement(STEP_INCREMENT);
        SpinnerValueFactory factory = new SpinnerValueFactory
            .DoubleSpinnerValueFactory(MIN, MAX, INITIAL_VALUE, STEP_INCREMENT);
        factory.setConverter(new PercentageStringConverter(
            NumberFormat.getPercentInstance()));
        Spinner spinner = new Spinner(factory);
        slider.valueProperty().bindBidirectional(spinner.getValueFactory().valueProperty());
        GridPane root = new GridPane();
        root.addRow(0, slider, spinner);
        root.setPadding(new Insets(8, 8, 8, 8));
        root.setHgap(8);
        Scene scene = new Scene(root);
        primaryStage.setScene(scene);
        primaryStage.show();
    }

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

}