java - JTextField 不编辑 JTextInput

Question

我正在尝试制作一个简单的程序，其中有一个文本输入字段和一个标签，当您在该字段中输入某些内容时，它将输入存储为“testInput”并将标签更改为该文本。我正在使用 Eclipse 的 Window Builder 插件来实现此目的，并且它以前工作得很好。现在发生的情况是它将接收文本，但不会将其发送回 jLabel。这是我的代码:

package interest;

import java.awt.EventQueue;

import javax.swing.JFrame;
import java.awt.GridBagLayout;
import javax.swing.JTextField;
import java.awt.GridBagConstraints;
import javax.swing.JLabel;
import java.awt.Insets;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;

public class TestWin {

String testInput;

private JFrame frame;
private JTextField txtTest;

/**
 * Launch the application.
 */
public static void main(String[] args) {
    EventQueue.invokeLater(new Runnable() {
        public void run() {
            try {
                TestWin window = new TestWin();
                window.frame.setVisible(true);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    });
}

/**
 * Create the application.
 */
public TestWin() {
    initialize();
}

/**
 * Initialize the contents of the frame.
 */
private void initialize() {
    frame = new JFrame();
    frame.setBounds(100, 100, 450, 300);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    GridBagLayout gridBagLayout = new GridBagLayout();
    gridBagLayout.columnWidths = new int[]{0, 0, 0, 0, 0, 0, 0};
    gridBagLayout.rowHeights = new int[]{0, 0, 0, 0, 0, 0};
    gridBagLayout.columnWeights = new double[]{0.0, 0.0, 0.0, 0.0, 0.0, 1.0, Double.MIN_VALUE};
    gridBagLayout.rowWeights = new double[]{0.0, 0.0, 0.0, 0.0, 0.0, Double.MIN_VALUE};
    frame.getContentPane().setLayout(gridBagLayout);

    txtTest = new JTextField(); 
    //Change label when enter is pressed
    txtTest.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent evt) {
            testInput = txtTest.getText();
            txtTest.setText(testInput);
        }
    });
    txtTest.setText("test");
    GridBagConstraints gbc_txtTest = new GridBagConstraints();
    gbc_txtTest.insets = new Insets(0, 0, 5, 0);
    gbc_txtTest.fill = GridBagConstraints.HORIZONTAL;
    gbc_txtTest.gridx = 5;
    gbc_txtTest.gridy = 1;
    frame.getContentPane().add(txtTest, gbc_txtTest);
    txtTest.setColumns(10);

    JLabel lblTest = new JLabel("test");
    GridBagConstraints gbc_lblTest = new GridBagConstraints();
    gbc_lblTest.gridx = 5;
    gbc_lblTest.gridy = 4;
    frame.getContentPane().add(lblTest, gbc_lblTest);
}

}

我确信我犯了一个非常简单的错误，因此非常感谢您的帮助!

Answer 1

放置

JLabel lblTest = new JLabel("test");

在 initialize() 的开头(或 txtTest.addActionListener... 上方的任何位置)，然后替换

txtTest.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent evt) {
        testInput = txtTest.getText();
        txtTest.setText(testInput);
    }
});

对于

txtTest.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent evt) {
        testInput = txtTest.getText();
        lblTest.setText(testInput);    //This line was changed.
    }
});