JavaFX滑块大小的值

Question

我在这里有一个滑块，它在滑块的拇指上显示一个数字。每当我拖动滑块时，数字就会增加或减少。我希望拇指显示一个整数而不是双精度。

import javafx.application.Application; 
import javafx.geometry.*; 
import javafx.scene.Scene; 
import javafx.scene.control.*; 
import javafx.scene.layout.*; 
import javafx.stage.Stage; 

public class SliderWithLabeledThumb extends Application { 
    public void start(Stage ps) { 
     Slider s = new Slider(); 

     StackPane root = new StackPane(s); 
     root.setPadding(new Insets(5)); 
     s.setOrientation(Orientation.VERTICAL); 
     s.setMin(49); 
     s.setMax(99); 
     s.setValue(51); 
     s.setMinorTickCount(0); 
     s.setMajorTickUnit(1); 

     Scene scene = new Scene(root); 

     s.applyCss(); 
     s.layout(); 
     Pane p = (Pane) s.lookup(".thumb"); 
     Label l = new Label(); 
     l.textProperty().bind(s.valueProperty().asString("%.1f").concat(" °")); 

     p.getChildren().add(l); 

     ps.setScene(scene); 
     ps.show(); 
    } 

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

当我改变参数为asString（）从 “％.1F” 发送给 “％d”，我得到一个异常

l.textProperty().bind(s.valueProperty().asString("%d").concat(" °")); 

错误消息：

Exception in Application start method 
Exception in thread "main" java.lang.RuntimeException: Exception in Application start method 
    at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:917) 
    at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$155(LauncherImpl.java:182) 
    at java.lang.Thread.run(Thread.java:745) 
Caused by: java.util.IllegalFormatConversionException: d != java.lang.Double 
    at java.util.Formatter$FormatSpecifier.failConversion(Formatter.java:4302) 
    at java.util.Formatter$FormatSpecifier.printInteger(Formatter.java:2793) 
    at java.util.Formatter$FormatSpecifier.print(Formatter.java:2747) 
    at java.util.Formatter.format(Formatter.java:2520) 
    at java.util.Formatter.format(Formatter.java:2455) 
    at java.lang.String.format(String.java:2940) 
    at com.sun.javafx.binding.StringFormatter$4.computeValue(StringFormatter.java:196) 
    at javafx.beans.binding.StringBinding.get(StringBinding.java:152) 
    at com.sun.javafx.binding.StringFormatter.format(StringFormatter.java:207) 
    at javafx.beans.binding.Bindings.format(Bindings.java:4846) 
    at javafx.beans.binding.NumberExpressionBase.asString(NumberExpressionBase.java:319) 
    at embeddedwebview.SliderWithLabeledThumb.start(SliderWithLabeledThumb.java:29) 
    at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$162(LauncherImpl.java:863) 
    at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$175(PlatformImpl.java:326) 
    at com.sun.javafx.application.PlatformImpl.lambda$null$173(PlatformImpl.java:295) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at com.sun.javafx.application.PlatformImpl.lambda$runLater$174(PlatformImpl.java:294) 
    at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95) 

这里是我的CSS文件：

.slider .track { 
    -fx-pref-height: 10px; 
    -fx-pref-width: 20px; 
} 

.slider .thumb { 
    -fx-pref-height: 30; 
    -fx-prefer-width: 30; 
} 

目前输出为止：

Answer 1

这个问题最终被中几乎是一个重复：

• Problem with System.out.printf command in Java

所以你不能使用%d格式化一个double值，则必须使用%f 。如果您只想显示double值的整数部分，则可以让%.0f（按照Hypnic Jerk的评论中的建议）对小数点后的位进行舍入（小数点不会显示）。根据formatting javadoc，使用round half up algorithm。

import javafx.application.Application; 
import javafx.geometry.*; 
import javafx.scene.Scene; 
import javafx.scene.control.*; 
import javafx.scene.layout.*; 
import javafx.stage.Stage; 

public class SliderWithLabeledThumb extends Application { 
    public void start(Stage ps) { 
     Slider s = new Slider(); 

     StackPane root = new StackPane(s); 
     root.setPadding(new Insets(5)); 
     s.setOrientation(Orientation.VERTICAL); 
     s.setMin(49); 
     s.setMax(99); 
     s.setValue(51); 
     s.setMinorTickCount(0); 
     s.setMajorTickUnit(1); 

     Scene scene = new Scene(root); 

     s.applyCss(); 
     s.layout(); 
     Pane p = (Pane) s.lookup(".thumb"); 
     Label l = new Label(); 
     l.textProperty().bind(s.valueProperty().asString("%.0f").concat(" °")); 

     p.getChildren().add(l); 

     ps.setScene(scene); 
     ps.show(); 
    } 

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