如何在Java中为数组中的项命名？

Question

我已经创建了JFields数组；

JFields[] field = new JField[5];

for(int j = 0; i < 5; i++) {
    field[j] = new JField();
}

我要做的是给数组中的每个项一个名称，例如field1、field2、field3、field4、Field5。

String[] field = {field1, field2, field3, field4, field5}

field[j] = {field1, field2, field3, field4, field5}

谢谢

Answer 1

这就是你的数组的作用。因为您有一个名为fields的JTextField数组，所以您已经为数组中的项（如Field[2]和Field[3]）指定了“名称”，所以这里不需要给变量指定“名称”。

你说：

我尝试了例如字段[0]或字段[1]等，但都不起作用。

编辑
例如：

import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;

import javax.swing.*;

@SuppressWarnings("serial")
public class TextFieldFun extends JPanel {
   public static final int TEXT_FIELD_COUNT = 8;
   private static final int COLS = 10;

   // array of JTextFields
   private JTextField[] fields = new JTextField[TEXT_FIELD_COUNT];

   // JTextField used to enter text to go into one of the array item fields
   private JTextField enterField = new JTextField(COLS);

   // spinner to choose which fields item to have its text set
   private JSpinner fieldIndexSpinner = new JSpinner(new SpinnerNumberModel(0, 0, TEXT_FIELD_COUNT - 1, 1));

   public TextFieldFun() {
      // JPanel to hold the array of fields
      JPanel textFieldPanel = new JPanel(new GridLayout(0, 1));
      for (int i = 0; i < fields.length; i++) {
         // create field items for array
         fields[i] = new JTextField(COLS);
         fields[i].setEditable(false);
         fields[i].setFocusable(false);
         JPanel rowPanel = new JPanel();
         rowPanel.add(new JLabel("Field " + i + ":"));
         rowPanel.add(fields[i]); // and put into a JPanel
         textFieldPanel.add(rowPanel);  // put JPanel into grid layout using JPanel
      }

      EnterAction enterAction = new EnterAction();
      enterField.setAction(enterAction);

      JPanel bottomPanel = new JPanel();
      bottomPanel.add(new JLabel("Row to Change:"));
      bottomPanel.add(fieldIndexSpinner);
      bottomPanel.add(new JLabel("Text:"));
      bottomPanel.add(enterField);
      bottomPanel.add(new JButton(enterAction));

      setLayout(new BorderLayout());
      add(textFieldPanel, BorderLayout.CENTER);
      add(bottomPanel, BorderLayout.SOUTH);
   }

   private class EnterAction extends AbstractAction {
      public EnterAction() {
         super("Enter");
      }
      @Override
      public void actionPerformed(ActionEvent e) {
         // get the text from the enterField JTextField
         String text = enterField.getText();

         // get the int from the JSpinner
         int index = ((Integer)fieldIndexSpinner.getValue()).intValue();

         // set the JTextField in the array whose index matches that of the spinner value
         fields[index].setText(text);
      }
   }

   private static void createAndShowGui() {
      TextFieldFun mainPanel = new TextFieldFun();

      JFrame frame = new JFrame("TextFieldFun");
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.getContentPane().add(mainPanel);
      frame.pack();
      frame.setLocationByPlatform(true);
      frame.setVisible(true);
   }

   public static void main(String[] args) {
      SwingUtilities.invokeLater(new Runnable() {
         public void run() {
            createAndShowGui();
         }
      });
   }
}