Data binding java8绑定两个浮点数

我所要做的就是将一个浮点数绑定到另一个浮点数：

import javafx.beans.property.FloatProperty;
import javafx.beans.property.SimpleFloatProperty;

public class BindingTest
{
   public static void main(String[] args) 
   {      
     float bound=0;
     float binder= -1;

     FloatProperty boundP= new SimpleFloatProperty(bound);
     FloatProperty binderP=new SimpleFloatProperty(binder);
     binderP.bind(boundP);
     System.out.println("Before: \n\tbinder: " +binder + "\n\tbound: " + bound);
     binder= 23; 
     System.out.println("After: \n\tbinder: " +binder + "\n\tbound: " + bound);

    }
}

如果您费心运行此操作，则当变量

活页夹

更改为值23时，变量

绑定

将不会更新。 我做错了什么？

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谢谢

所以我认为你对属性如何工作的想法是错误的。为了更好地理解，我举了一个例子：

import javafx.beans.binding.Bindings;
import javafx.beans.binding.NumberBinding;
import javafx.beans.property.FloatProperty;
import javafx.beans.property.SimpleFloatProperty;

public class Test {

  public static void main(String... args) {
    FloatProperty dummyProp = new SimpleFloatProperty(0);
    FloatProperty binderP = new SimpleFloatProperty(-1);
    //Means boundP = dummyProp + binderP
    NumberBinding boundP = Bindings.add(binderP, dummyProp);
    System.out.format("%f + %f = %f%n", dummyProp.floatValue(), binderP.floatValue(), boundP.floatValue());
    dummyProp.set(2);
    System.out.format("%f + %f = %f%n", dummyProp.floatValue(), binderP.floatValue(), boundP.floatValue());

    // dummyProp is equal to binderP but dummyProp is a read-only value
    dummyProp.bind(binderP);
    System.out.format("%f, %f%n", dummyProp.floatValue(), binderP.floatValue());
    // throws an exception because dummyProp is bound to binderP
    // dummyProp.set(5);
    binderP.set(5f);
    System.out.format("%f, %f%n", dummyProp.floatValue(), binderP.floatValue());

    dummyProp.unbind();

    // dummyProp == binderP always
    dummyProp.bindBidirectional(binderP);
    System.out.format("%f, %f%n", dummyProp.floatValue(), binderP.floatValue());
    dummyProp.set(3f);
    System.out.format("%f, %f%n", dummyProp.floatValue(), binderP.floatValue());
    binderP.set(10f);
    System.out.format("%f, %f%n", dummyProp.floatValue(), binderP.floatValue());

    // boundP always consists of the sum
    System.out.format("%f%n", boundP.floatValue());
  }

}

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我认为您需要再次阅读教程来了解绑定是如何工作的：Thank flwn--在下面的回答中发布了回复您知道值调用是什么意思吗？谢谢，明白了。非常感谢！