Java 从外部调用时 Swing 标签未更新 class

Question

我正在尝试使用 java swing 中串口的数据更新 JTextBox。我面临的问题是 JTextBox 没有得到更新。我也尝试了 repaint() 和 revalidate 函数，但没有使用。我还尝试将 setText() 放入可运行对象中。什么都不管用。请指导我。

public class PrinterUI extends javax.swing.JFrame{

/**
 * Creates new form PrinterUI
 */
public PrinterUI() {
    initComponents();
    initOtherUI();
}

public void initOtherUI(){
    menu = new ArrayList<javax.swing.JMenuItem>();
}

public void showSensorValueOnScreen(long id, int pres, int temp){
    System.out.println(Long.toHexString(id));
    sensorID = id;
    System.out.println(Long.toHexString(sensorID));
    
    opText.setText(Long.toHexString(sensorID));
}



/**
 * This method is called from within the constructor to initialize the form.
 * WARNING: Do NOT modify this code. The content of this method is always
 * regenerated by the Form Editor.
 */
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">                          
private void initComponents() {

    jMenu3 = new javax.swing.JMenu();
    jButton1 = new javax.swing.JButton();
    jLabel1 = new javax.swing.JLabel();
    opText = new javax.swing.JTextField();
    jMenuBar1 = new javax.swing.JMenuBar();
    printerMenuBar = new javax.swing.JMenu();
    mobileMenuBar = new javax.swing.JMenu();

    jMenu3.setText("jMenu3");

    setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

    jButton1.setText("Print");
    jButton1.addMouseListener(new java.awt.event.MouseAdapter() {
        public void mouseClicked(java.awt.event.MouseEvent evt) {
            jButton1MouseClicked(evt);
        }
    });

    jLabel1.setText("Sensor Output");

    opText.setText("jTextField1");
    opText.addPropertyChangeListener(new java.beans.PropertyChangeListener() {
        public void propertyChange(java.beans.PropertyChangeEvent evt) {
            opTextPropertyChange(evt);
        }
    });

    printerMenuBar.setText("Printer");
    printerMenuBar.addMouseListener(new java.awt.event.MouseAdapter() {
        public void mouseClicked(java.awt.event.MouseEvent evt) {
            printerMenuBarMouseClicked(evt);
        }
        public void mouseEntered(java.awt.event.MouseEvent evt) {
            printerMenuBarMouseEntered(evt);
        }
    });
    jMenuBar1.add(printerMenuBar);

    mobileMenuBar.setText("Mobile");
    jMenuBar1.add(mobileMenuBar);

    setJMenuBar(jMenuBar1);

    javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
    getContentPane().setLayout(layout);
    layout.setHorizontalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(layout.createSequentialGroup()
            .addGap(203, 203, 203)
            .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addComponent(opText, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addComponent(jLabel1)
                .addComponent(jButton1))
            .addContainerGap(236, Short.MAX_VALUE))
    );
    layout.setVerticalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
            .addContainerGap(108, Short.MAX_VALUE)
            .addComponent(jLabel1)
            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
            .addComponent(opText, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addGap(52, 52, 52)
            .addComponent(jButton1)
            .addGap(105, 105, 105))
    );

    getAccessibleContext().setAccessibleName("jLabel1");

    pack();
}// </editor-fold>                        

private void printerMenuBarMouseClicked(java.awt.event.MouseEvent evt) {                                            
    System.out.println("clicked");
}                                           

private void printerMenuBarMouseEntered(java.awt.event.MouseEvent evt) {                                            
    String[] portNames = null;
    portNames = SerialPortList.getPortNames();
    for (String string : portNames) {
        System.out.println(string);
    }
    
    if (portNames.length == 0) {
        System.out.println("There are no serial-ports");
    } else {

        SerialPort serialPort = new SerialPort("COM25");
        try {
            serialPort.openPort();

            serialPort.setParams(SerialPort.BAUDRATE_9600,    SerialPort.DATABITS_8, SerialPort.STOPBITS_1,
                    SerialPort.PARITY_NONE);
            serialPort.setFlowControlMode(SerialPort.FLOWCONTROL_RTSCTS_IN | SerialPort.FLOWCONTROL_RTSCTS_OUT);

            PortReader portReader = new PortReader(serialPort);

            serialPort.addEventListener(portReader, SerialPort.MASK_RXCHAR);
        } catch (Exception e) {
            System.out.println("There are an error on writing string to port т: " + e);
        }
    }
     
     
}                                           

private void jButton1MouseClicked(java.awt.event.MouseEvent evt) {                                      
    // TODO add your handling code here:
    System.out.println("Print Click");
    opText.setText(Long.toString(sensorID));
    System.out.println(Long.toHexString(sensorID));        
}                                     
                                

/**
 * @param args the command line arguments
 */
public static void main(String args[]) {
    /* Set the Nimbus look and feel */
    //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
    /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
     * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
     */
    try {
        for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
            if ("Nimbus".equals(info.getName())) {
                javax.swing.UIManager.setLookAndFeel(info.getClassName());
                break;
            }
        }
    } catch (ClassNotFoundException ex) {
        java.util.logging.Logger.getLogger(PrinterUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (InstantiationException ex) {
        java.util.logging.Logger.getLogger(PrinterUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (IllegalAccessException ex) {
        java.util.logging.Logger.getLogger(PrinterUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (javax.swing.UnsupportedLookAndFeelException ex) {
        java.util.logging.Logger.getLogger(PrinterUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    }
    //</editor-fold>

    /* Create and display the form */
    java.awt.EventQueue.invokeLater(new Runnable() {
        public void run() {
            new PrinterUI().setVisible(true);
        }
    });
}

private List<javax.swing.JMenuItem> menu;
PrintService pservice = null;
public static long sensorID;


// Variables declaration - do not modify                     
private javax.swing.JButton jButton1;
private javax.swing.JLabel jLabel1;
private javax.swing.JMenu jMenu3;
private javax.swing.JMenuBar jMenuBar1;
private javax.swing.JMenu mobileMenuBar;
private javax.swing.JTextField opText;
private javax.swing.JMenu printerMenuBar;
// End of variables declaration

}

class PortReader implements SerialPortEventListener{

SerialPort serialPort;
public int[] incomingData = new int[20];
public int dataIndex=0;
public long sensorID=0;
public int pressure;
public int temperature;

public PortReader(SerialPort serialPort) {
    this.serialPort = serialPort;
}

@Override
public void serialEvent(SerialPortEvent event) {
    if (event.isRXCHAR() && event.getEventValue() > 0) {
        try {
            String receivedData = serialPort.readHexString();
            
            for(int x=0;x<receivedData.length();x=x+2){
                int data = Integer.parseInt(receivedData.substring(x, x+2),16);
                //System.out.println(data);
                if((dataIndex==0)&&(data==170)){
                    incomingData[dataIndex++]=data;
                }else if(dataIndex>0){
                    incomingData[dataIndex++]=data;
                    if(dataIndex>=14){   
                        dataIndex=0;
                        long tyreId =(long)(((int)incomingData[6])*16777216 + ((int)incomingData[7])*65536 + ((int)incomingData[8])*256 + ((int)incomingData[9]));
                        tyreId = tyreId & 0x00000000FFFFFFFFL;
                        int press = incomingData[10];
                        int temp = incomingData[11];
                        sensorID = tyreId;
                        pressure = press;
                        temperature = temp;
                        
                        PrinterUI obj = new PrinterUI();
                        obj.showSensorValueOnScreen(sensorID, pressure, temperature);
                        
                        System.out.println("ID: " + Long.toHexString(tyreId) + ", Pressure: " + pressure + ", Temperature: " + temperature);
                    }
                }else{
                    dataIndex=0;
                }
            }
        } catch (SerialPortException ex) {
            System.out.println("Error in receiving string from COM-port: " + ex);
        }
    }
}

}

当接收到串行数据时，在 PortReader class 中调用 serialEvent，后者又在 PrinterUI class 中调用 showSensorValueOnScreen() 方法。 JTextBox 小部件未更新。

但是当按下 UI 上的按钮时，JTextBox 会更新。

为什么当我从 class 外部调用它时它没有得到更新？。请帮帮我。

Answer 1

我发现了问题。我正在尝试通过为 UI 创建一个新对象来从另一个 class 更新 UI。实际的 UI 是使用不同的对象从 void main 创建的。

我通过将现有对象传递给调用 UI 更新函数的 class 来解决它。

谢谢大家的帮助。

Java 从外部调用时 Swing 标签未更新 class

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