有人可以向我解释为什么当我将JOptionPane
放入ItemListener
时为什么我丢失了选择(由setSelected()
设置)为JCheckBox
? 这是一个错误?为什么setSelected on JCheckBox失去效果?
很奇怪,如果这个过程延迟invokeLater()
,setSelected()
正如我所料。
从SSCCE
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class ComponentEventDemo extends JPanel
implements ComponentListener, ItemListener {
private static final long serialVersionUID = 1L;
private JFrame frame;
private JTextArea display;
private String newline = "\n";
private JTextField field1;
public ComponentEventDemo() {
super(new BorderLayout());
display = new JTextArea(10, 25);
display.setEditable(false);
JPanel panel = new JPanel(new GridLayout(0, 2));
field1 = new JTextField();
field1.setDisabledTextColor(Color.red);
JCheckBox checkbox = new JCheckBox("Label visible", true);
checkbox.addItemListener(this);
panel.add(checkbox);
panel.add(field1);
panel.addComponentListener(this);
JScrollPane scrollPane = new JScrollPane(display);
frame = new JFrame("ComponentEventDemo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(scrollPane, BorderLayout.CENTER);
frame.add(panel, BorderLayout.SOUTH);
frame.addComponentListener(this);
frame.setLocation(200, 200);
frame.pack();
frame.setVisible(true);
}
public void itemStateChanged(ItemEvent evt) {
System.out.println("STATE CHANGED!");
if (evt.getStateChange() == ItemEvent.SELECTED) {
//javax.swing.SwingUtilities.invokeLater(new Runnable() {
//public void run() {
int returnVal = JOptionPane.showConfirmDialog(display,
"Bla Bla Bla Text");
if (returnVal == JOptionPane.OK_OPTION) {
field1.setText("SELECTED - OK btn");
} else if (returnVal == JOptionPane.NO_OPTION) {
field1.setText("SELECTED - NO btn");
} else if (returnVal == JOptionPane.CANCEL_OPTION) {
field1.setText("SELECTED - Cancel btn");
} else if (returnVal == JOptionPane.CLOSED_OPTION) {
field1.setText("SELECTED - Close btn");
}
//}
//});
} else if (evt.getStateChange() == ItemEvent.DESELECTED) {
field1.setText("DESELECTED");
}
}
protected void displayMessage(String message) {
display.append(message + newline);
display.setCaretPosition(display.getDocument().getLength());
}
public void componentHidden(ComponentEvent e) {
displayMessage(e.getComponent().getClass().getName() + " ---> Hidden");
}
public void componentMoved(ComponentEvent e) {
displayMessage(e.getComponent().getClass().getName() + " ---> Moved");
}
public void componentResized(ComponentEvent e) {
displayMessage(e.getComponent().getClass().getName() + " ---> Resized ");
}
public void componentShown(ComponentEvent e) {
displayMessage(e.getComponent().getClass().getName() + " ---> Shown");
}
public static void main(String[] args) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
ComponentEventDemo ced = new ComponentEventDemo();
}
});
}
}
1+ question。我已经看到过这个,并且已经解决了它 - 通过排队在EDT上显示JOptionPane,但是我无法解释它,因为我没有时间或精力来揣测源代码。 –
@Hovercraft Full Of Eels我在这里发布这个问题之前调试了Java API方法,一切都看起来像是正确的,在这两种情况下通知器都是在这个方法内部完成的,但我仍然找不到差异(Java方法内的步骤)纯JCheckBox和JCheckBox与JOptionPane,感谢您的确认 – mKorbel