我正在尝试创建从一个 JPanel 到下一个 JPanel 的平滑动画，其中第二个 JPanel 比第一个 JPanel 更高更宽，需要我重新缩放 JFrame。为此，我创建了以下代码:
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.WindowConstants;
public class Example1 extends JFrame
{
/**
*
*/
private static final long serialVersionUID = 1L;
public Example1()
{
initComponents();
}
public static void main(String[] args)
{
try
{
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); // get look and feel based on OS
}
catch (ClassNotFoundException ex) // catch all errors that may occur
{
Logger.getLogger(Example1.class.getName()).log(Level.SEVERE, null, ex);
}
catch (InstantiationException ex)
{
Logger.getLogger(Example1.class.getName()).log(Level.SEVERE, null, ex);
}
catch (IllegalAccessException ex)
{
Logger.getLogger(Example1.class.getName()).log(Level.SEVERE, null, ex);
}
catch (UnsupportedLookAndFeelException ex)
{
Logger.getLogger(Example1.class.getName()).log(Level.SEVERE, null, ex);
}
EventQueue.invokeLater(new Runnable()
{
public void run() // run the class's constructor, therefore starting
// the UI being built
{
new Example1().setVisible(true);;
}
});
}
private WindowListener exitListener = new WindowAdapter()
{
@Override
public void windowClosing(WindowEvent e)
{
closingEvent(); // if window closing, go to exit menu
}
};
private void initComponents() // method to build initial view for user for installation
{
// instantiating elements of the GUI
pnlStart = new JPanel();
lblMain = new JLabel();
lblDivider = new JLabel();
lblTextPrompt = new JLabel();
txtAccNum = new JTextField();
btnNext = new JButton();
btnExit = new JButton();
pnlStart.setVisible(true);
add(pnlStart); // adding the panel to the frame
removeWindowListener(exitListener);
addWindowListener(exitListener); // removing before adding the windowlistener, ensures there is only one listener there
setDefaultCloseOperation(WindowConstants.DO_NOTHING_ON_CLOSE); // setting "x" button to do nothing except what exitListener does
setPreferredSize(new Dimension(600, 400)); // setting measurements of jframe
setTitle("Example 1.0"); // setting title on JFrame
setResizable(false); // disabling resizing
setLayout(null); // ensuring I can specify element positions
setBackground(Color.WHITE); // setting background color
lblMain.setText("<html>Please input a number below how many accounts you would like to<br>create: </html>"); // main label that explains what happens, html used for formatting
lblMain.setFont(lblMain.getFont().deriveFont(18.0f)); // changing font size to 16
lblMain.setBounds(27, 60, 540, 100); // setting position and measurements
add(lblMain); // adding label to JFrame
lblTextPrompt.setText("Amount of accounts (1-10):");
lblTextPrompt.setFont(lblMain.getFont().deriveFont(16.0f));
lblTextPrompt.setBounds(166, 190, 198, 18);
lblTextPrompt.setLabelFor(txtAccNum);
add(lblTextPrompt);
txtAccNum.setFont(lblMain.getFont());
txtAccNum.setBounds(374, 187, 50, 26);
txtAccNum.addKeyListener(new KeyAdapter()
{
public void keyTyped(KeyEvent e)
{
if (txtAccNum.getText().length() >= 4) // limit textfield to 3 characters
e.consume();
}
});
txtAccNum.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
AccDetails(Integer.parseInt(txtAccNum.getText()));
}
});
add(txtAccNum);
lblDivider.setText(""); // ensuring no text in label
lblDivider.setBounds(10, 285, 573, 10); // setting bounds and position of dividing line
lblDivider.setBorder(BorderFactory.createMatteBorder(0, 0, 1, 0, Color.LIGHT_GRAY)); // setting border to label for the dividing
add(lblDivider); // adding it to JFrame
btnNext.setText("Next"); // adding text to button for starting
btnNext.setFont(lblMain.getFont().deriveFont(14.0f)); // setting font size
btnNext.setBounds(495, 315, 80, 35); // positioning start button
btnNext.addActionListener(new ActionListener() // add listener for action to run method
{
public void actionPerformed(ActionEvent evt)
{
AccDetails(Integer.parseInt(txtAccNum.getText()));
}
});
add(btnNext); // adding button to JFrame
btnExit.setText("Exit"); // adding text to button for exiting
btnExit.setFont(btnNext.getFont()); // getting font from start button
btnExit.setBounds(20, 315, 80, 35); // positioning on form
btnExit.addActionListener(new ActionListener() // add listener for action to run method
{
public void actionPerformed(ActionEvent evt)
{
closingEvent(); // running cancel method (same method as hitting the "x" button on the form)
}
});
add(btnExit); // adding button to JFrame
repaint(); // repainting what is displayed if going coming from a different form
revalidate(); // revalidate the elements that will be displayed
pack(); // packaging everything up to use
setLocationRelativeTo(null); // setting form position central
txtAccNum.requestFocusInWindow(); // setting focus on start button when everything is loaded
}
private void AccDetails(int accNum)
{
getContentPane().removeAll();
// instantiating elements of the GUI
pnlAccDetails = new JPanel();
pnlAccDetails.setVisible(true);
add(pnlAccDetails); // adding the panel to the frame
removeWindowListener(exitListener);
addWindowListener(exitListener); // removing before adding the windowlistener, ensures there is only one listener there
setDefaultCloseOperation(WindowConstants.DO_NOTHING_ON_CLOSE); // setting "x" button to do nothing except what exitListener does
while (sizeW != 750 && sizeH != 500)
{
setBackground(Color.BLACK);
Point loc = getLocationOnScreen();
setPreferredSize(new Dimension(sizeW, sizeH));
pnlAccDetails.setPreferredSize(new Dimension(sizeW, sizeH));
repaint();
revalidate();
pack();
sizeW += 1.5;
sizeH += 1;
if (toggle)
{
setLocation((int)(loc.getX() - 0.75), (int)(loc.getY() - 0.5));
toggle = false;
}
else
{
toggle = true;
}
try
{
Thread.sleep(1);
}
catch (InterruptedException e)
{
e.printStackTrace();
}
}
setTitle("Example 1.0"); // setting title on JFrame
setResizable(false); // disabling resizing
setLayout(null); // ensuring I can specify element positions
setBackground(Color.WHITE); // setting background color
repaint(); // repainting what is displayed if going coming from a different form
revalidate(); // revalidate the elements that will be displayed
pack(); // packaging everything up to use
setLocationRelativeTo(null); // setting form position central
}
private void closingEvent()
{
if (JOptionPane.showConfirmDialog(null, "<html><center>Are you sure you want to quit?</center></html>", "Quit?", JOptionPane.YES_NO_OPTION, JOptionPane.WARNING_MESSAGE) == JOptionPane.YES_OPTION)
System.exit(0); // output warning that it would cancel installation, if accepted...
else // if not accepted...
{
}
}
// objects used in UI
private JPanel pnlStart;
private JPanel pnlAccDetails;
private JLabel lblMain;
private JLabel lblDivider;
private JLabel lblTextPrompt;
private JTextField txtAccNum;
private JButton btnNext;
private JButton btnExit;
private int sizeW = 600;
private int sizeH = 400;
private boolean toggle = false;
}
虽然此代码确实有效，但在调整大小期间，表单不会保留其背景颜色，而是具有带有新测量值的黑色轮廓。据我所知，根据我所做的研究，这是由于所使用的渲染引擎造成的。是否有办法强制渲染引擎在每次迭代时运行，或者是否有其他方法可以做到这一点？我已经看到了使用通用补间引擎的建议，但是我找不到任何调整大小的示例，特别是对于 JFrame。 提前致谢
最佳答案
如上述评论(@Sergiy Medvynskyy)所述，阻塞 Swing 线程会导致其无法正确渲染。通过使用 Swing Timer，动画可以顺利运行。我用于解决方案的代码是:
timer = new Timer (10, new ActionListener() {
@Override
public void actionPerformed(ActionEvent arg0)
{
Point loc = getLocationOnScreen();
setPreferredSize(new Dimension(sizeW, sizeH));
pnlAccDetails.setPreferredSize(new Dimension(sizeW, sizeH));
repaint();
revalidate();
pack();
sizeW += 3;
sizeH += 2;
if (toggle)
{
setLocation((int)(loc.getX() - 0.75), (int)(loc.getY() - 0.5));
toggle = false;
}
else
{
toggle = true;
}
if (sizeW == 750 && sizeH == 500)
{
timer.stop();
}
}
});
timer.start();
上面的代码用于代替我原来问题中的 while 循环。感谢 Sergiy Medvynskyy 的回答。
关于java - 调整 JFrame 大小时的黑色轮廓，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/44653202/