我在关闭SWT对话框时遇到了小部件异常。我知道这告诉我，某些东西试图调用一个小部件，但是我无法找到这种情况发生的原因。以下是我的代码摘录：
final Display display = Display.getCurrent();
final Shell shell = new Shell(display, SWT.RESIZE | SWT.CLOSE | SWT.MIN | SWT.MAX | SWT.APPLICATION_MODAL);
final ConstraintDialog dialog = new ConstraintDialog(shell);
dialog.open();
protected Control createDialogArea(final Composite parent) {
final Composite container = (Composite) super.createDialogArea(parent);
container.setLayout(new RowLayout(SWT.VERTICAL));
final Label lblSource = new Label(grpNewConstraint, SWT.NONE);
lblSource.setFont(JFaceResources.getFontRegistry().getBold(""));
lblSource.setLayoutData(new GridData(SWT.CENTER, SWT.CENTER, false, false, 1, 1));
lblSource.setText("Source Feature");
new Label(grpNewConstraint, SWT.NONE);
final ListViewer lvConstraints = new ListViewer(grpExistingConstraints, SWT.V_SCROLL);
lvConstraints.setContentProvider(new ConstraintDialogContentProvider());
lvConstraints.setLabelProvider(new ConstraintDialogLabelProvider());
lvConstraints.setInput(this.fm);
final List listConstraints = lvConstraints.getList();
final GridData gd_listConstraints = new GridData(SWT.LEFT, SWT.TOP, true, true, 1, 1);
gd_listConstraints.heightHint = 120;
listConstraints.setLayoutData(gd_listConstraints);
final Button btnAddConstraint = new Button(composite_Buttons, SWT.NONE);
btnAddConstraint.setToolTipText("Use th form above to add a new Constraint");
btnAddConstraint.setText("Add Constraint");
btnAddConstraint.addSelectionListener(new SelectionAdapter() {
public void widgetSelected(final SelectionEvent event) {
..........
lvConstraints.refresh();
final Point grpSize = grpExistingConstraints.computeSize(SWT.DEFAULT, SWT.DEFAULT);
grpExistingConstraints.setSize(grpSize);
....
});
这是错误堆栈，它根本没有帮助我找到错误的来源：
org.eclipse.swt.SWTException: Widget is disposed
at org.eclipse.swt.SWT.error(SWT.java:4397)
at org.eclipse.swt.SWT.error(SWT.java:4312)
at org.eclipse.swt.SWT.error(SWT.java:4283)
at org.eclipse.swt.widgets.Widget.error(Widget.java:472)
at org.eclipse.swt.widgets.Widget.checkWidget(Widget.java:344)
at org.eclipse.swt.widgets.Control.addFocusListener(Control.java:190)
at org.eclipse.jface.viewers.DialogCellEditor$2.widgetSelected(DialogCellEditor.java:247)
at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:248)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1057)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4170)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3759)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$9.run(PartRenderingEngine.java:1113)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:997)
at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:138)
at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:610)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:567)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:150)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:124)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:354)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:181)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:636)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:591)
at org.eclipse.equinox.launcher.Main.run(Main.java:1450)
at org.eclipse.equinox.launcher.Main.main(Main.java:1426)
如果我打开并关闭窗口小部件，则不会出现任何异常。但是当我打开对话框时，执行一些操作（使用按钮）并关闭它，显示异常
------------更新-------------------
由于您的评论，我已扩展了我的代码段：
public CellEditor createPropertyEditor(final Composite parent) {
return new ExtendedDialogCellEditor(parent, getLabelProvider()) {
@SuppressWarnings("synthetic-access")
@Override
protected Object openDialogBox(final Control cellEditorWindow) {
final Display display = Display.getCurrent();
final Shell shell = new Shell(display, SWT.RESIZE | SWT.CLOSE | SWT.MIN | SWT.MAX
| SWT.APPLICATION_MODAL);
if (ConstraintPropertyDescriptor.this.object instanceof FeatureModel) {
final FeatureModel fm = (FeatureModel) ConstraintPropertyDescriptor.this.object;
final ConstraintDialog dialog = new ConstraintDialog(fm, shell);
dialog.open();
}
return null;
}
};
}