我想从 Window->prefernce->change font 选项更改文本字段的字体。我实现了代码。但是在更新文本字段时会发生什么，我得到了以下 classcast 异常。以下是在首选项中添加字体对话框的代码
public class SampleViewPreferencePage extends FieldEditorPreferencePage implements
IWorkbenchPreferencePage {
public SampleViewPreferencePage() {
super(GRID);
}
public void createFieldEditors() {
addField(new FontFieldEditor("font", "Font selection",
getFieldEditorParent()));
}
@Override
public void init(IWorkbench workbench) {
setPreferenceStore(SvtActivator.getDefault().getPreferenceStore());
}
}
SampleView-> createPartControl()
/**
* This is a callback that will allow us to create the viewer and initialize
* it.
*/
public void createPartControl(Composite parent) {
super.createPartControl(parent);
FillLayout layout = new FillLayout();
layout.marginHeight = layout.marginWidth = 10;
parent.setLayout(layout);
text = new StyledText(parent, SWT.V_SCROLL | SWT.H_SCROLL
| SWT.MULTI | SWT.BORDER);
text.setText("");
}
@Override
public void propertyChange(org.eclipse.jface.util.PropertyChangeEvent event) {
System.out.println("Value changed..");
Object newValue = event.getNewValue();
System.out.println("newValue: "+newValue);
//if (newValue instanceof FontData) {
Font font = new Font(Display.getCurrent(),
(FontData) newValue);
getText().setFont(font);
//}
}
java.lang.ClassCastException: [Lorg.eclipse.swt.graphics.FontData; cannot be cast to org.eclipse.swt.graphics.FontData
at com.example.MyView.propertyChange(MyView.java:111)
at org.eclipse.ui.preferences.ScopedPreferenceStore$3.run(ScopedPreferenceStore.java:375)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
at org.eclipse.ui.preferences.ScopedPreferenceStore.firePropertyChangeEvent(ScopedPreferenceStore.java:372)
at org.eclipse.jface.preference.PreferenceConverter.setValue(PreferenceConverter.java:463)
at org.eclipse.jface.preference.FontFieldEditor.doStore(FontFieldEditor.java:242)
at org.eclipse.jface.preference.FieldEditor.store(FieldEditor.java:680)
at org.eclipse.jface.preference.FieldEditorPreferencePage.performOk(FieldEditorPreferencePage.java:343)
at org.eclipse.jface.preference.PreferencePage.performApply(PreferencePage.java:432)
at org.eclipse.jface.preference.PreferencePage$2.widgetSelected(PreferencePage.java:281)
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:1053)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4169)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3758)
at org.eclipse.jface.window.Window.runEventLoop(Window.java:825)
at org.eclipse.jface.window.Window.open(Window.java:801)
at org.eclipse.ui.internal.dialogs.WorkbenchPreferenceDialog.open(WorkbenchPreferenceDialog.java:215)
at org.eclipse.ui.internal.handlers.ShowPreferencePageHandler.execute(ShowPreferencePageHandler.java:54)
at org.eclipse.ui.internal.handlers.HandlerProxy.execute(HandlerProxy.java:290)
at org.eclipse.core.commands.Command.executeWithChecks(Command.java:499)
at org.eclipse.core.commands.ParameterizedCommand.executeWithChecks(ParameterizedCommand.java:508)
at org.eclipse.ui.internal.handlers.HandlerService.executeCommand(HandlerService.java:169)
at org.eclipse.ui.internal.handlers.SlaveHandlerService.executeCommand(SlaveHandlerService.java:241)
at org.eclipse.ui.menus.CommandContributionItem.handleWidgetSelection(CommandContributionItem.java:829)
at org.eclipse.ui.menus.CommandContributionItem.access$19(CommandContributionItem.java:815)
at org.eclipse.ui.menus.CommandContributionItem$5.handleEvent(CommandContributionItem.java:805)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1053)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4169)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3758)
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2701)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2665)
at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2499)
at org.eclipse.ui.internal.Workbench$7.run(Workbench.java:679)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:668)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
at de.allianz.abs.konvertortool.product.Application.start(Application.java:20)
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:353)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:180)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:629)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:584)
at org.eclipse.equinox.launcher.Main.run(Main.java:1438)
at org.eclipse.equinox.launcher.Main.main(Main.java:1414)