在使用Java中的自定义单元格渲染器重新渲染JTable时，我遇到了冻结SWING GUI的问题。所以我问了问题“Why does a JTable view update block the entire GUI?”。答案指出，没有修改JTable并覆盖doLayout的JList可能是更好的选择。所以我用JList实现了这个例子并遇到了同样的问题：在生成数据时，一切正常，进度条移动。但是当视图更新时，程序会冻结，进度条会停止移动。
请注意，sleep语句只是为了让生成时间更长，更真实（通过JDBC读取数千个数据集并从中创建对象需要花费很多时间）。可以删除它并增加生成的项目数。但是你可以清楚地看到，HTML呈现速度很慢。但我需要这些颜色和两条线（如果不一定有这么多不同的颜色）。
那么请你告诉我，我的错误在哪里？我认为，EDT和其他工作是通过单独的线程分开的，我看不到任何错误。
更新：我环顾四周，发现了这个问题“https://stackoverflow.com/a/20813122/2429611”。有说：
更有趣的问题是如何避免UI阻塞，但我认为只有Swing才有可能，你必须实现一些延迟加载或批量渲染。
这意味着，我无法解决我的问题。这是对的吗？
package example;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.security.SecureRandom;
import java.util.ArrayList;
import java.util.List;
import javax.swing.AbstractAction;
import javax.swing.AbstractListModel;
import javax.swing.Box;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JProgressBar;
import javax.swing.JScrollPane;
import javax.swing.ListCellRenderer;
import javax.swing.SwingUtilities;
public class ListExample extends AbstractListModel {
static List<DemoObject> internalList = new ArrayList<>();
@Override
public int getSize() {
return internalList.size();
}
@Override
public DemoObject getElementAt(int index) {
return internalList.get(index);
}
public void fireContentsChanged() {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
fireContentsChanged(this, 0, -1);
}
});
}
static class MyCellRenderer extends JLabel implements ListCellRenderer<ListExample.DemoObject> {
public MyCellRenderer() {
setOpaque(true);
}
@Override
public Component getListCellRendererComponent(JList<? extends ListExample.DemoObject> list,
ListExample.DemoObject value,
int index,
boolean isSelected,
boolean cellHasFocus) {
setText("<html>" + value.toString()
+ "<br/>"
+ "<span bgcolor=\"#ff0000\">Line 2; Color = " + value.c + "</span>");
Color background;
Color foreground;
// check if this cell represents the current DnD drop location
JList.DropLocation dropLocation = list.getDropLocation();
if (dropLocation != null
&& !dropLocation.isInsert()
&& dropLocation.getIndex() == index) {
background = Color.BLUE;
foreground = Color.WHITE;
// check if this cell is selected
} else if (isSelected) {
background = Color.RED;
foreground = Color.WHITE;
// unselected, and not the DnD drop location
} else {
background = value.c; //Color.WHITE;
foreground = Color.BLACK;
};
setBackground(background);
setForeground(foreground);
return this;
}
}
static class DemoObject {
String str;
Color c;
public DemoObject(String str, int color) {
this.str = str;
this.c = new Color(color);
}
@Override
public String toString() {
return str;
}
}
static JPanel overlay;
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
JFrame frame = new JFrame("Example");
frame.setLayout(new BorderLayout(4, 4));
// Add JTable
final ListExample model = new ListExample();
JList list = new JList(model);
list.setCellRenderer(new MyCellRenderer());
frame.add(new JScrollPane(list), BorderLayout.CENTER);
// Add button
Box hBox = Box.createHorizontalBox();
hBox.add(new JButton(new AbstractAction("Load data") {
@Override
public void actionPerformed(ActionEvent e) {
new Thread(new Runnable() {
@Override
public void run() {
overlay.setVisible(true);
internalList.clear();
System.out.println("Generating data ...");
SecureRandom sr = new SecureRandom();
for (int i = 0; i < 10000; i++) {
internalList.add(
new DemoObject(
"String: " + i + " (" + sr.nextFloat() + ")",
sr.nextInt(0xffffff)
)
);
// To create the illusion, that data are
// fetched via JDBC (which takes a little
// while), this sleep statement is embedded
// here. In a real world scenario, this wait
// time is caused by talking to the database
// via network
if (i%10 == 0) {
try {
Thread.sleep(1);
} catch (Exception e) {
}
}
}
System.out.println("Updating view ...");
model.fireContentsChanged();
overlay.setVisible(false);
System.out.println("Finished.");
}
}).start();
}
}));
hBox.add(Box.createHorizontalGlue());
frame.add(hBox, BorderLayout.NORTH);
// Create loading overlay
overlay = new JPanel(new FlowLayout(FlowLayout.CENTER)) {
@Override
protected void paintComponent(Graphics g) {
g.setColor(new Color(0, 0, 0, 125));
g.fillRect(0, 0, getWidth(), getHeight());
super.paintComponent(g);
}
};
overlay.setOpaque(false);
overlay.setBackground(new Color(0, 0, 0, 125));
JProgressBar bar = new JProgressBar();
bar.setIndeterminate(true);
overlay.add(bar);
frame.setGlassPane(overlay);
frame.getGlassPane().setVisible(false);
// Create frame
frame.setSize(600, 400);
frame.setVisible(true);
}
});
}
}
答案 0 :(得分：1)
有三个问题（重新创建，重置模型，并且自定义渲染器停止工作）
JList (JComboBox hasn't) has an issue by removing more than 999 items，您必须将新模型设置为JList
看到重要的ComboBoxModel扩展AbstractListModel为setElementAt实现MutableComboBoxModel（以保持当前选择）
public void fireContentsChanged() {的使用是错误的，看不出使用这种方式的理由，再次即将更换电流，重置模型
。例如成功atr运行时和/ if事件（触发）的重新测试
setModel(new DefaultListModel(list.toArray()) {
protected void fireContentsChanged(Object obj, int i, int j) {
if (!isFired)
super.fireContentsChanged(obj, i, j);
}
});