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在開發我的應用程序對Java 5之後，我最近在6中進行了測試，發現我有一個paintComponent問題。Java paintComponent覆蓋版本5和版本6之間的區別
在jre5中發生了什麼是屏幕開始變暗，按鈕「前景」出現在調光面板的頂部（如預期的那樣）。在jre6中，按鈕完全不會出現，但您確實會得到調光。您可以通過將鼠標移動到其位置來強制該按鈕（強制翻轉以重新繪製它）。我可以稍微重新排列代碼以使按鈕出現在jre6中，但變暗的面板總是塗在按鈕的頂部。
我假設它運氣好於判斷它在jre5中可以工作但在網上找不到多少幫助。任何可以幫助你解決這個問題的方法都是非常值得讚賞的。
我產生了下面的代碼，以顯示該問題：
import java.awt.AlphaComposite;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.Timer;
@SuppressWarnings("serial")
public class TranslucentGlass extends JPanel
{
public static void main(String[] args)
{
// Create a frame
JFrame f = new JFrame();
JPanel mainPanel = new JPanel(new BorderLayout());
JLabel bgLabel = new JLabel(System.getProperty("java.version"));
mainPanel.add(bgLabel, BorderLayout.SOUTH);
// create a panel for the glasspane
final JPanel glassPane = new JPanel();
glassPane.setLayout(new BorderLayout());
glassPane.setVisible(false);
glassPane.setOpaque(false);
// create the containing panel for the 'foreground' button
final JPanel largePanel = new JPanel(new BorderLayout());
largePanel.setOpaque(false);
largePanel.setBorder(BorderFactory.createEmptyBorder(0, 20, 50, 20));
largePanel.add(new JButton("Foreground"), BorderLayout.SOUTH);
// set the glass pane and mainpanel
f.add(mainPanel);
f.setGlassPane(glassPane);
f.setPreferredSize(new Dimension(250, 250));
f.addWindowListener(new WindowAdapter()
{
@Override
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
});
// an action to show or hide the panel on mouse clicked
f.addMouseListener(new MouseAdapter()
{
boolean panelVisible = false;
@Override
public void mouseClicked(MouseEvent e)
{
if(!panelVisible)
{
glassPane.removeAll();
TranslucentGlass dimmingPanel = new TranslucentGlass(false);
dimmingPanel.add(largePanel);
glassPane.add(dimmingPanel);
dimmingPanel.startTimer();
glassPane.setVisible(true);
panelVisible = true;
}
else
{
glassPane.setVisible(false);
panelVisible = false;
}
}
});
f.pack();
f.setVisible(true);
}
private Timer timer;
private float opacity = 0;
private long sysTime = System.currentTimeMillis();
private static final int TIMER_INTERVAL = 50; // measured in milliseconds
private static final int TIMER_TOTAL = 750; // measured in milliseconds
private static final Color FADE_COLOUR = Color.RED;
private static final float FINAL_OPACITY = 0.3f;
public TranslucentGlass()
{
this(true);
}
public TranslucentGlass(boolean startTimer)
{
super();
setOpaque(false);
setLayout(new BorderLayout());
// Create a new timer to change the opacity over time and repaint the panel
timer = new Timer(TIMER_INTERVAL, new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
long newSysTime = System.currentTimeMillis();
opacity += FINAL_OPACITY * (newSysTime - sysTime)/TIMER_TOTAL;
sysTime = newSysTime;
validate();
repaint();
if(opacity >= FINAL_OPACITY)
{
timer.stop();
}
}
});
if(startTimer)
{
timer.start();
}
}
public void startTimer()
{
timer.start();
}
// Override the paintComponent calling paintComponent*s* to ensure the panels contents are painted
@Override
protected void paintComponent(Graphics g)
{
final Graphics2D g2 = (Graphics2D) g;
g2.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, opacity));
g2.setColor(FADE_COLOUR);
g2.fillRect(0, 0, getWidth(), getHeight());
g2.dispose();
super.paintComponents(g);
}
}
我以前在任何自定義組件中都沒有看到過這個，但出於某種原因處置'Graphics2D'導致了問題。刪除該代碼行使它更好，但沒有完全解決它。創建'Graphics'的副本並使用該副本似乎可以做到。 – Tony 2012-02-16 18:46:14
感謝您的支持。 – Remlap21 2012-02-17 11:41:34