不使用 repaint()、revalidate() 刷新 GUI

Question

我有一个包含多个面板的框架。每当我 press/release/click 中央面板时，JLabel 都会显示我执行此类操作的次数和坐标。问题是 window 没有刷新，所以 JLabel 上的所有这些值都保持为 0。通常使用 paintComponents 我会使用 repaint()，但我没有使用这种方法。

这是我应该 'repaint':

的代码片段

public void mousePressed(MouseEvent e) {
    pressCounter++;
    x = e.getX();
    y = e.getY();
    buildIt(); //this works, but doesn't do what i want it to do
}

调用buildIt()确实有效，但它会在每次操作后打开一个新的window，而不是刷新原来的window。我在这里也试过 revalidate() 和 removeAll()，但它们似乎什么也没做。

那么我该如何刷新 window？

完整代码供参考：

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

class MouseMonitor extends JPanel implements MouseListener {
    JFrame frame;
    JPanel topPanel, centerPanel, bottomPanel;
    JLabel pressLabel, releaseLabel, clickLabel, xLabel, yLabel;

    int pressCounter = 0;
    int releaseCounter = 0;
    int clickCounter = 0;

    int x, y;

    void buildIt() {
        frame = new JFrame("Mouse Monitor");
        topPanel = new JPanel();
        centerPanel = new JPanel();
        bottomPanel = new JPanel();
        pressLabel = new JLabel("pressed: " + pressCounter);
        releaseLabel = new JLabel("released: " + releaseCounter);
        clickLabel = new JLabel("clicked: " + clickCounter);
        xLabel = new JLabel("x-coordinate: " + x);
        yLabel = new JLabel("y-coordinate: " + y);

        frame.add(topPanel, BorderLayout.NORTH);
        frame.add(centerPanel, BorderLayout.CENTER);
        frame.add(bottomPanel, BorderLayout.SOUTH);
        topPanel.add(pressLabel);
        topPanel.add(releaseLabel);
        topPanel.add(clickLabel);
        bottomPanel.add(xLabel);
        bottomPanel.add(yLabel);
        pressLabel.setBorder(BorderFactory.createLineBorder(Color.WHITE));
        releaseLabel.setBorder(BorderFactory.createLineBorder(Color.WHITE));
        clickLabel.setBorder(BorderFactory.createLineBorder(Color.WHITE));
        xLabel.setBorder(BorderFactory.createLineBorder(Color.WHITE));
        yLabel.setBorder(BorderFactory.createLineBorder(Color.WHITE));

        Color color = new Color(193, 236, 255);
        centerPanel.setBackground(color);
        centerPanel.addMouseListener(this);

        frame.setSize(300, 300);
        frame.setVisible(true);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }

    public void mousePressed(MouseEvent e) {
        pressCounter++;
        x = e.getX();
        y = e.getY();
        buildIt();
    }

    public void mouseReleased(MouseEvent e) {
        releaseCounter++;
    }

    public void mouseClicked(MouseEvent e) {
        clickCounter++;
    }

    public void mouseEntered(MouseEvent e) { }
    public void mouseExited(MouseEvent e) { }

    public static void main(String[] args) {
        new MouseMonitor().buildIt();
    }
}

Answer 1

您不需要调用 built() 方法来刷新框架或面板。为了你想要的目的，你只需要改变标签上的文字。因此，例如，考虑 mousePressed(MouseEvent e) 方法，取出 buildIt() 方法：

    public void mousePressed(MouseEvent e) {
        pressCounter++;
        pressLabel.setText("pressed: " + pressCounter);

    }

对每种方法执行此操作，您就可以开始了。维护 main 方法中的代码。

不使用 repaint()、revalidate() 刷新 GUI

Refreshing GUI without using repaint(), revalidate()

java

user-interface

refresh