我正在尝试从SerialRead方法设置数据变量，但我得到了＃34;无法对非静态字段Etiqueta2进行静态引用＆＃34;，Eclipse说我应该使Etiqueta2静态但它不会显示Jlabel中的数据。
public class Final extends JFrame
{
//Crea Elementos de la interfaz
JLabel Etiqueta=new JLabel();
JTextField Texto=new JTextField();
JButton Boton=new JButton();
JLabel Etiqueta1=new JLabel();
JLabel Etiqueta2=new JLabel();
JButton Boton1=new JButton();
public Final()
{
super();
// Crea la interfaz
setVisible(true);
setLayout(null);
setTitle("Lectura y escritura de datos");
setSize(380,200);
//Propiedades de los elementos del Frame
// Etiqueta
Etiqueta.setBounds(20,50, 100, 20);
Etiqueta.setText("Enviar un digito");
add(Etiqueta);
// Caja de texto
Texto.setBounds(120,50,100, 20);
add(Texto);
// Boton
Boton.setBounds(250,50,100, 20);
Boton.setText("Enviar");
add(Boton);
// Etiqueta 1
Etiqueta1.setBounds(20,80, 100, 20);
Etiqueta1.setText("Leer un digito");
add(Etiqueta1);
// Etiqueta2
Etiqueta2.setBounds(120,80,100, 20);
add(Etiqueta2);
// Boton 1
Boton1.setBounds(250,80,100, 20);
Boton1.setText("Leer");
add(Boton1);
// Boton de cierre
setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
}
void connect ( String portName ) throws Exception
{
CommPortIdentifier portIdentifier = CommPortIdentifier.getPortIdentifier(portName);
if ( portIdentifier.isCurrentlyOwned() )
{
System.out.println("Error: Port is currently in use");
}
else
{
CommPort commPort = portIdentifier.open(this.getClass().getName(),2000);
if ( commPort instanceof SerialPort )
{
SerialPort serialPort = (SerialPort) commPort;
serialPort.setSerialPortParams(9600,SerialPort.DATABITS_8,SerialPort.STOPBITS_1,SerialPort.PARITY_NONE);
InputStream in = serialPort.getInputStream();
OutputStream out = serialPort.getOutputStream();
new SerialReader(in, Etiqueta2).execute();
(new Thread(new SerialWriter(out))).start();
}
else
{
System.out.println("Error: Only serial ports are handled by this example.");
}
}
}
/** */
public static class SerialReader extends SwingWorker<Void, String> { //Final frame = new Final();
private InputStream in;
private JLabel label;
public SerialReader(InputStream in, JLabel label) {
this.in = in;
this.label = label;
}
@Override
protected void process(List<String> chunks) {
String data = chunks.get(chunks.size() - 1);
label.setText(data);
}
@Override
protected Void doInBackground() throws Exception {
byte[] buffer = new byte[1024];
int len = -1;
while ((len = this.in.read(buffer)) > -1) {
String data = new String(buffer, 0, len);
System.out.println(data);
publish(data);
}
return null;
}
}
/** */
public static class SerialWriter implements Runnable
{
**** output code ****
}
public static void main ( String[] args )
{
try
{
(new Final()).connect("COM7");
}
catch ( Exception e )
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
如何在Etiqueta2标签上设置setText以显示数据变量？
由于
EDIT3：我使用swingworker更新了代码，执行并打印了控制台中的数据
答案 0 :(得分：2)
SerialReader是Final的静态内部类，因此无法访问Final中的任何非静态字段。由于您显然不在SerialReader之外使用Final，只需将其设为非静态（甚至可以是私有内部类）。同样适用于SerialWriter。
答案 1 :(得分：1)
SerialReader被声明为static，因此它无法访问外部Final类的实例字段，因为它可以创建{{1}的实例首先不需要SerialReader的实例。
相反，您应该将要更新的Final的引用传递给JLabel类
SerialReader然后你可以在你的run方法中使用它进行更新。
你可以简单地让这个课程非静态，但这取决于你的需要
你遇到的另一个问题是Swing不是线程安全的，所以从public static class SerialReader implements Runnable
{ //Final frame = new Final();
InputStream in;
private JLabel label;
public SerialReader ( InputStream in, JLabel label ) {
this.label = label;
//...
方法中调用setText实例上的JLabel实际上是不可取的。< / p>
通常情况下，我建议使用run，因为它有一些方法可以让您在后台线程中获得SwingWorker个结果，并在事件的上下文中使用publish个结果调度线程，允许您安全地修改UI的状态，但在这种情况下，您可以使用process
SwingUtilities.invokeLater但您可能需要 public void run ()
{
//...
try
{
while ( ( len = this.in.read(buffer)) > -1 )
{
//...
SwingUtiltiies.invokeLater(new Runnable() {
public void run() {
Etiqueta2.setText(data);
}
});
}
}
catch ( IOException e )
{
e.printStackTrace();
}
}
data，这可能会导致更多问题，在这种情况下，我只需使用final。
仔细查看Worker Threads and SwingWorker了解更多详情
SwingWorker示例...... SwingWorkerpublic static class SerialReader extends SwingWorker<Void, String> { //Final frame = new Final();
private InputStream in;
private JLabel label;
public SerialReader(InputStream in, JLabel label) {
this.in = in;
this.label = label;
}
@Override
protected void process(List<String> chunks) {
String data = chunks.get(chunks.size() - 1);
label.setText(data);
}
@Override
protected Void doInBackground() throws Exception {
byte[] buffer = new byte[1024];
int len = -1;
while ((len = this.in.read(buffer)) > -1) {
String data = new String(buffer, 0, len);
publish(data);
}
return null;
}
}
示例...... SwingWorkerimport java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GridBagLayout;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingWorker;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private JLabel label;
public TestPane() {
setLayout(new GridBagLayout());
label = new JLabel("...");
add(label);
new ClockWorker(label).execute();
}
@Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
}
public static class ClockWorker extends SwingWorker<Void, String> {
protected static final DateFormat DF = new SimpleDateFormat("hh:mm.ss SSS a");
private JLabel label;
public ClockWorker(JLabel label) {
this.label = label;
}
@Override
protected void process(List<String> chunks) {
label.setText(chunks.get(chunks.size() - 1));
}
@Override
protected Void doInBackground() throws Exception {
while (true) {
publish(DF.format(new Date()));
Thread.sleep(1);
}
}
}
}
示例...... InputStream