好的，所以这个程序的目标是将红色x从“桥”的一侧（由7个JButton组成）到窗口的另一侧。我想在循环的每个循环之后让按钮刷新显示在它们上面的文本，这样看起来红色x穿过桥。根据以下代码提供的任何帮助都不会令人难以置信。
感谢您的时间
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class GeorgeBridge extends JApplet implements ActionListener{
// Create a frame to hold the contents of application
JFrame frame = new JFrame ("George's Big Bridge Crossing");
// Panel to hold the bridge
JPanel bridgePanel = new JPanel(new GridLayout(1,7));
/* The following JLabels are used for spacing of the panels in the frame to make the window look more like a bridge
* crossing over a river
*/
JLabel northLabel = new JLabel(" ");
JLabel eastLabel = new JLabel(" ");
JLabel westLabel = new JLabel(" ");
// Asks the user whether or not they would like George to cross the bridge
JLabel southLabel = new JLabel("Would you like George to cross the Bridge?");
// George is represented by a red X
String george = "X";
// An array of 7 JButtons to act as the bridge
JButton [] bridge = new JButton [7];
int spot;
public void init() {
bridge[0] = new JButton ("");
bridge[1] = new JButton ("");
bridge[2] = new JButton ("");
bridge[3] = new JButton ("");
bridge[4] = new JButton ("");
bridge[5] = new JButton ("");
bridge[6] = new JButton ("");
// Set the program to exit when the JFrame is closed
frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
//set a border layout manager to the frame
frame.setLayout(new BorderLayout());
// Background set to look like water under the bridge
bridgePanel.setBackground (new Color(0,191,246));
// Panel to make it look like the bridge is crossing a river
JPanel northPanel = new JPanel();
northPanel.setBackground (new Color (0,191,246));
// Panel to make it look like the bridge is crossing a river
JPanel eastPanel = new JPanel();
eastPanel.setBackground (new Color (0,184,48));
// Panel to make it look like the bridge is crossing a river
JPanel southPanel = new JPanel();
southPanel.setBackground (new Color (0,191,246));
// Panel to make it look like the bridge is crossing a river
JPanel westPanel = new JPanel();
westPanel.setBackground (new Color(0,184,48));
// JButton to let the user choose when George crosses the bridge
JButton cross = new JButton("Make George cross!");
cross.setActionCommand("cross");
cross.addActionListener(this);
// Starts George standing on the West Bank
westLabel.setText(george);
// Makes George red so he is more visible
westLabel.setForeground(new Color(255,0,0));
// Makes George size 24 font so he is more visible
westLabel.setFont(westPanel.getFont().deriveFont(24.0f));
// Initiates the first button that represents a foot of the bridge
// bridge[0] = new JButton ("");
bridge[0].setBackground(new Color(143,66,19));// Set the background to a brown to make the bridge look like a wooden bridge
bridge[0].setForeground(new Color(255,0,0));// Set the colour of George to red
bridge[0].setFont(bridge[0].getFont().deriveFont(24.0f));// Set the font for George to 24
// Initiates the second button that represents a foot of the bridge
// bridge[1] = new JButton ("");
bridge[1].setBackground(new Color(143,66,19));// Set the background to a brown to make the bridge look like a wooden bridge
bridge[1].setForeground(new Color(255,0,0));// Set the colour of George to red
bridge[1].setFont(bridge[0].getFont().deriveFont(24.0f));// Set the font for George to 24
// Initiates the third button that represents a foot of the bridge
// bridge[2] = new JButton ("");
bridge[2].setBackground(new Color(143,66,19));// Set the background to a brown to make the bridge look like a wooden bridge
bridge[2].setForeground(new Color(255,0,0));// Set the colour of George to red
bridge[2].setFont(bridge[0].getFont().deriveFont(24.0f));// Set the font for George to 24
// Initiates the fourth button that represents a foot of the bridge
// bridge[3] = new JButton ("");
bridge[3].setBackground(new Color(143,66,19));// Set the background to a brown to make the bridge look like a wooden bridge
bridge[3].setForeground(new Color(255,0,0));// Set the colour of George to red
bridge[3].setFont(bridge[0].getFont().deriveFont(24.0f));// Set the font for George to 24
// Initiates the fifth button that represents a foot of the bridge
// bridge[4] = new JButton ("");
bridge[4].setBackground(new Color(143,66,19));// Set the background to a brown to make the bridge look like a wooden bridge
bridge[4].setForeground(new Color(255,0,0));// Set the colour of George to red
bridge[4].setFont(bridge[0].getFont().deriveFont(24.0f));// Set the font for George to 24
// Initiates the sixth button that represents a foot of the bridge
// bridge[5] = new JButton ("");
bridge[5].setBackground(new Color(143,66,19));// Set the background to a brown to make the bridge look like a wooden bridge
bridge[5].setForeground(new Color(255,0,0));// Set the colour of George to red
bridge[5].setFont(bridge[0].getFont().deriveFont(24.0f));// Set the font for George to 24
// Initiates the seventh button that represents a foot of the bridge
// bridge[6] = new JButton ("");
bridge[6].setBackground(new Color(143,66,19));// Set the background to a brown to make the bridge look like a wooden bridge
bridge[6].setForeground(new Color(255,0,0));// Set the colour of George to red
bridge[6].setFont(bridge[0].getFont().deriveFont(24.0f));// Set the font for George to 24
// Add the bridge buttons to the bridge panel
bridgePanel.add(bridge[0]);
bridgePanel.add(bridge[1]);
bridgePanel.add(bridge[2]);
bridgePanel.add(bridge[3]);
bridgePanel.add(bridge[4]);
bridgePanel.add(bridge[5]);
bridgePanel.add(bridge[6]);
// Add the labels and buttons to the 4 border panels
northPanel.add(northLabel);
eastPanel.add(eastLabel);
southPanel.add(southLabel);
southPanel.add(cross);
westPanel.add(westLabel);
// Add all the panels to the JFrame
frame.getContentPane().add(northPanel, BorderLayout.NORTH);
frame.getContentPane().add(eastPanel, BorderLayout.EAST);
frame.getContentPane().add(bridgePanel, BorderLayout.CENTER);
frame.getContentPane().add(southPanel, BorderLayout.SOUTH);
frame.getContentPane().add(westPanel, BorderLayout.WEST);
// Set the JFrame size and visibility
frame.setSize(450,150);
frame.setVisible(true);
}
public void actionPerformed (ActionEvent event) {
new Thread (new Runnable() {
public void run() {
moveGeorge();
}
}).start();
}
public void moveGeorge() {
for(int i=0; i<7; i++) {
spot = i;
SwingUtilities.invokeLater(new Runnable() {
public void run() {
if (spot > 0) {
bridge[spot].setText(george);
bridge[spot-1].setText("");
}
else {
westLabel.setText("");
bridge[spot].setText(george);
}
try
{
Thread.sleep(1000); // do nothing for 1000 miliseconds (1 second)
}
catch(InterruptedException e)
{
e.printStackTrace();
}
frame.setVisible(true);
}
});
}
}
}
答案 0 :(得分：3)
Thread.sleep(1000); // do nothing for 1000 miliseconds (1 second)
在Event Dispatch Thread上执行代码时，切勿使用Thread.sleep（）。这可以防止GUI响应事件和重新绘制自己。
该代码需要移出invokeLater（）代码。
有关EDT的详细信息，请参阅Concurrency in Swing。
答案 1 :(得分：0)
偏离主题，但不适合评论：
使用Color.RED等定义的值
Color brown = new Color (143,66,19);
for (int i = 0; i < 7; ++i)
{
bridge[i] = new JButton ("");
bridge[i].setBackground (brown);
bridge[i].setForeground (Color.RED);
bridge[i].setFont (bridge [0].getFont ().deriveFont (24.0f));
bridgePanel.add (bridge[i]);
}
这可以节省30行代码。
答案 2 :(得分：-1)
首先，swing不是线程安全的。
而不是使用Thread.sleep（）并使用EDT（事件派发线程）拧紧其次，在修改$ {JComponent}后立即尝试添加一个$ {JComponent} .revalidate（）和$ {JComponent} .repaint（）
例如
// Starts George standing on the West Bank
westLabel.setText(george);
// Makes George red so he is more visible
westLabel.setForeground(new Color(255,0,0));
// Makes George size 24 font so he is more visible
westLabel.setFont(westPanel.getFont().deriveFont(24.0f));
//VVVV NOW ADD THIS VVVV
westLabel.revalidate();
westLabel.repaint();