java - IProgressMonitor .worked(int) 不更新进度条

Question

我正在为 Eclipse 插件 (3.7) 使用 IProgressMonitor。各种方法调用 .setTaskName(String) 和 .worked(int)。当我运行它时，它正在执行的任务会更新，但进度条上的绿色进度永远不会前进。以下是部分代码:

IProgressMonitor.beginTask 在这里被调用，然后 doFinish 被调用，监视器被传递给它:

public boolean performFinish() {
    IRunnableWithProgress op = new IRunnableWithProgress() {
        public void run(IProgressMonitor monitor) throws InvocationTargetException {
            try {
                monitor.beginTask("Building project...", 10);
                doFinish(projectNamePage.getComposite(), new GridLayout(), monitor);
            } catch (CoreException e1) {
                e1.printStackTrace();
            } finally {
                monitor.done();
            }
        }
    };
    try {
        getContainer().run(false, false, op);
    } catch (InterruptedException e) {
        return false;
    } catch (InvocationTargetException e) {
        Throwable realException = e.getTargetException();
        MessageDialog.openError(getShell(), "Error", realException.getMessage());
        e.printStackTrace();
        return false;
    }
    return true;
}

doFinish 方法委托(delegate)给其他方法。

private void doFinish(Composite container, GridLayout layout, IProgressMonitor pmp) throws CoreException {
    //Get the root of the current Eclipse workspace
    IWorkspaceRoot iwr = ResourcesPlugin.getWorkspace().getRoot();

    //Create a new project with the name requested in SampleNewWizardPage.
    IProject project = iwr.getProject(projectNamePage.getFileName().split("\\.")[0]);
    IProjectDescription description = null;
    project.create(pmp);
    project.open(pmp);
    description = project.getDescription();
    pmp.worked(1);

    IJavaProject javaProject = setProjectDescription(description, project, pmp);
    setRawClasspathEntryList(pmp, javaProject);
    IFolder sourceFolder = buildSourceFolder(project, pmp);
    String jarFilePath = downloadAlgoraphJar(javaProject, iwr, pmp);

    buildAlgoSettingsFile(javaProject, iwr, pmp);

    populateClasspath(sourceFolder, javaProject, jarFilePath, pmp);
    buildPackageWithSkeleton(javaProject, sourceFolder, pmp);
}

这是 doFinish 委托(delegate)给的方法之一的示例:

private void setRawClasspathEntryList(IProgressMonitor pmp, IJavaProject javaProject) {
    pmp.setTaskName("Building classpath...");
    List<IClasspathEntry> entries = new ArrayList<IClasspathEntry>();
    entries.add(JavaRuntime.getDefaultJREContainerEntry());
    try {
        javaProject.setRawClasspath(entries.toArray(new IClasspathEntry[entries.size()]), pmp);
    } catch (JavaModelException e) {
        e.printStackTrace();
    }
    pmp.worked(1);
}

Answer 1

如果在 UI Thread 中调用 run()，则必须将 fork 设置为 true。 (也就是说，可运行实例不应在 UI 线程中运行。)

UI 线程处理 UI 事件，如更新进度条、重绘等。但是如果你在 UI 线程中运行一个耗时的任务，线程就不能处理事件，因为它很忙。 (任务完成后会处理事件)