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我正在尝试使用在 TimerTask 中更新的 Bean 类提供的值更新 JLabel 中显示的文本。
Bean 得到了很好的更新,但 JLabel 没有。
为了说明这个问题,我构建了一个由以下组成的小项目:

  • 设置和获取将与我的 JLabel 绑定的字符串变量的类 Bean
    package test;
    
    public class Bean {
        private String value;
        public Bean() {
            setValue("Created");
        }
        public String getValue() {
            return value;
        }
        public void setValue(String value) {
            this.value = value;
        }
    }
  • TimerTask (UpdateTask) 用于更新 Bean 中的变量(在其值中添加一个 'X')
    package test;
    
    import java.util.TimerTask;
    
    public class UpdateTask  extends TimerTask{
        private Bean bean;
        public UpdateTask(Bean bean) {
            this.bean=bean;
        }
    
        @Override
        public void run() {
            System.out.println("UpdateTask - Bean = " + bean.getValue());
            bean.setValue(bean.getValue() +"X");
            System.out.println("UpdateTask - Bean = " + bean.getValue());
        }
    
    }
  • 一个 TimerTask (ViewTask) 只用于输出控制台中 Bean 变量和 JLabel 的值

    package test;
    
    import java.util.TimerTask;
    
    import javax.swing.JLabel;
    
    public class ViewTask  extends TimerTask{
        private JLabel lbl;
        private Bean bean;
        public ViewTask(JLabel lbl, Bean bean) {
            this.lbl=lbl;
            this.bean=bean;
        }
    
        @Override
        public void run() {
            System.out.println("ViewTask - Bean:" + bean.getValue());
            System.out.println("ViewTask - Label:" + lbl.getText());
        }
    
    }

  • 显示带有 JLabel 的 Frame 的主类,创建 Bean,初始化 DataBinding 并启动我的 2 个计时器

    package test;
    
    import java.awt.EventQueue;
    import java.util.Timer;
    
    import javax.swing.JFrame;
    import javax.swing.JLabel;
    import java.awt.BorderLayout;
    import org.jdesktop.beansbinding.BeanProperty;
    import org.jdesktop.beansbinding.AutoBinding;
    import org.jdesktop.beansbinding.Bindings;
    import org.jdesktop.beansbinding.AutoBinding.UpdateStrategy;
    
    public class Panel {
    
        private JFrame frame;
        private Bean bean;
        private JLabel lblNewLabel;
    
        /**
         * Launch the application.
         */
        public static void main(String[] args) {
            EventQueue.invokeLater(new Runnable() {
                public void run() {
                    try {
                        Panel window = new Panel();
                        window.frame.setVisible(true);
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            });
        }
    
        /**
         * Create the application.
         */
        public Panel() {
            initialize();
            bean =new Bean();
            new Timer().schedule(new ViewTask(lblNewLabel, bean), 0, 1000);
            new Timer().schedule(new UpdateTask(bean), 0, 1000);
        }
    
        /**
         * Initialize the contents of the frame.
         */
        private void initialize() {
            frame = new JFrame();
            frame.setBounds(100, 100, 100, 100);
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);   
            frame.getContentPane().setLayout(new BorderLayout(0, 0));           
            lblNewLabel = new JLabel("New label");
            frame.getContentPane().add(lblNewLabel);
            initDataBindings();
        }
        protected void initDataBindings() {
            BeanProperty<Bean, String> beanBeanProperty = BeanProperty.create("value");
            BeanProperty<JLabel, String> jLabelBeanProperty = BeanProperty.create("text");
            AutoBinding<Bean, String, JLabel, String> autoBinding = Bindings.createAutoBinding(UpdateStrategy.READ, bean, beanBeanProperty, lblNewLabel, jLabelBeanProperty);
            autoBinding.bind();
        }
    }

  • windowsBuilder中显示的我的绑定属性:

绑定.jpg

在运行时,控制台中的输出如下:


    ViewTask - Bean:Created  
    UpdateTask - Bean = Created  
    ViewTask - Label:New label  
    UpdateTask - Bean = CreatedX  
    UpdateTask - Bean = CreatedX  
    UpdateTask - Bean = CreatedXX  
    ViewTask - Bean:CreatedX  
    ViewTask - Label:New label  
    UpdateTask - Bean = CreatedXX  
    UpdateTask - Bean = CreatedXXX  
    ViewTask - Bean:CreatedXX  
    ViewTask - Label:New label  
    UpdateTask - Bean = CreatedXXX  
    UpdateTask - Bean = CreatedXXXX  
    ViewTask - Bean:CreatedXXX         <--- Bean is updated  
    ViewTask - Label:New label         <--- Label is not updated  

有人可以帮我找出问题所在吗?谢谢

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0 回答 0