Question

我在java编程，我想刷新我的Jframe并通过循环更改颜色，但我无法重新加载框架，但我只能创建一个新框架。

package frames;
import java.awt.Color;

import javax.swing.*;

public class Frame1 {
public static void main(String[] args) 
{
    int num = 0;



    while (num<255)
    {
        num +=1;
        JFrame frame = new JFrame();
        frame.setSize(400,300);
        frame.setVisible(true);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().setBackground(new Color(num,num,num));
        frame.setTitle("");

    }
}
}

Answer 1

您只需要使用一个框架（您创建了255个框架）
请勿使用while循环尝试更改背景。请改用Swing Timer。请参阅How to Use Swing Timers
在Event Dispatch Thread上运行所有Swing应用程序。请参阅Initial Threads

这是你用这三点重构的代码

import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
import javax.swing.Timer;

public class Frame1 {
    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                final JFrame frame = new JFrame();
                frame.getContentPane().setBackground(
                        new Color(0, 0, 0));
                Timer timer = new Timer(10, new ActionListener() {
                    int num = 0;
                    public void actionPerformed(ActionEvent e) {
                        if (num > 255) {
                            ((Timer) e.getSource()).stop();
                        } else {
                            frame.getContentPane().setBackground(
                                    new Color(num, num, num));
                            num++;
                        }
                    }
                });
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setSize(300, 300);
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
                timer.start();
            }
        });
    }
}

Answer 2

像这样，只会创建一个框架，您可以调整颜色并进行所需的刷新。

package frames;
import java.awt.Color;

import javax.swing.*;

public class Frame1 {
public static void main(String[] args) 
{
    int num = 0;

    JFrame frame = new JFrame();
    frame.setSize(400,300);
    frame.setVisible(true);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    frame.setTitle("");

    while (num<255)
    {
        num +=1;

        SwingUtilities.invokeLater(new Runnable() {
         public void run() {
         // Here, we can safely update the GUI
         // because we'll be called from the
         // event dispatch thread
          frame.getContentPane().setBackground(new Color(num,num,num));
          frame.pack();
          frame.repaint();
         }
        }
}
  });


    }
}
}

也许我只是混淆了}但你应该知道如何做到这一点

如何重新加载JFrame - Java

2 个答案: