我有一个类，它使用 jcombobox 和 jtextfield init 创建一个框架，用户在其中插入一些数据。然后我有另一个类，其中用户使用摇摆调用该类。虽然 swing 类工作正常，但当我从另一个类调用它时，它只会在程序终止后出现。我需要打开它，直到用户插入数据，然后单击确定，以便可以在代码中进一步使用输入的数据。
我用这个调用swing类main：
new constraints();
constraints.main(null);
摆动类主要是：
public static void main(String[] args)
{
Runnable runnable = new Runnable()
{
@Override
public void run()
{
new constraints().displayGUI();
}
};
EventQueue.invokeLater(runnable);
}
完整代码：
public class constraints {
private static JTextField tField;
private MyDocumentFilter documentFilter;
private JLabel amountLabel;
private static String amountString = "Select Quantity of Products (in ktones): ";
public static String textstr = "" ;
public static String sig="" ;
public static String sigfinal="";
private void displayGUI()
{
// final JFrame frame = new JFrame("Constraints");
final JDialog dialog = new JDialog();
// frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
dialog.setDefaultCloseOperation(
JDialog.DISPOSE_ON_CLOSE);
amountLabel = new JLabel(amountString);
JPanel contentPane = new JPanel();
contentPane.setBorder(
BorderFactory.createEmptyBorder(5, 5, 5, 5));
tField = new JTextField(10);
amountLabel.setLabelFor(tField);
String[] Strings = { "Less", "Equal", "More"};
final JComboBox combo = new JComboBox(Strings) ;
combo.setSelectedIndex(0);
JButton button = new JButton("Ok");
button.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent ae){
textstr = tField.getText();
sig = (String) combo.getSelectedItem();
if (sig=="Less") {
sigfinal="l";
}else if (sig=="Equal"){
sigfinal="e" ;
}else if (sig=="More"){
sigfinal="m";
}
}
});
JButton button2 = new JButton("Close");
button2.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e)
{
dialog.dispose();
}
});
((AbstractDocument)tField.getDocument()).setDocumentFilter(
new MyDocumentFilter());
contentPane.add(amountLabel);
contentPane.add(combo);
contentPane.add(tField);
contentPane.add(button);
contentPane.add(button2);
// JRootPane rootPane = frame.getRootPane();
JRootPane rootPane = dialog.getRootPane();
rootPane.setDefaultButton(button);
dialog.pack();
dialog.setVisible(true);
dialog.setContentPane(contentPane);
dialog.setLocationByPlatform(true);
// frame.setContentPane(contentPane);
// frame.pack();
// frame.setLocationByPlatform(true);
// frame.setVisible(true);
}
public static void main(String[] args)
{
Runnable runnable = new Runnable()
{
@Override
public void run()
{
new constraints().displayGUI();
}
};
EventQueue.invokeLater(runnable);
}
}
class MyDocumentFilter extends DocumentFilter
{
@Override
public void insertString(DocumentFilter.FilterBypass fp
, int offset, String string, AttributeSet aset)
throws BadLocationException
{
int len = string.length();
boolean isValidInteger = true;
for (int i = 0; i < len; i++)
{
if (!Character.isDigit(string.charAt(i)))
{
isValidInteger = false;
break;
}
}
if (isValidInteger)
super.insertString(fp, offset, string, aset);
else
Toolkit.getDefaultToolkit().beep();
}
@Override
public void replace(DocumentFilter.FilterBypass fp, int offset
, int length, String string, AttributeSet aset)
throws BadLocationException
{
int len = string.length();
boolean isValidInteger = true;
for (int i = 0; i < len; i++)
{
if (!Character.isDigit(string.charAt(i)))
{
isValidInteger = false;
break;
}
}
if (isValidInteger)
super.replace(fp, offset, length, string, aset);
else
Toolkit.getDefaultToolkit().beep();
}
}
错误：
Exception in thread "AWT-EventQueue-0" java.awt.IllegalComponentStateException: The window is showing on screen.
at java.awt.Window.setLocationByPlatform(Unknown Source)
at constraints.displayGUI(constraints.java:101)
at constraints.access$1(constraints.java:29)
at constraints$3.run(constraints.java:116)
at java.awt.event.InvocationEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$200(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
