Java Eclipse RCP:clonePerspective返回null

我想克隆一个透视图并保存克隆的透视图。但是，对的调用返回null，我已经不知道我的参数值可能有什么问题了

public void savePerspectiveAs(String label) {
    IWorkbenchPage page = PlatformUI.getWorkbench()
            .getActiveWorkbenchWindow().getActivePage();
    IPerspectiveDescriptor perspectiveDescriptor = perspectiveRegistry
            .findPerspectiveWithLabel(label);

    // if the perspective doesn't exist, create a new one 
    // by cloning the current perspective
    if (perspectiveDescriptor == null) {
        IPerspectiveDescriptor currentPerspectiveDescriptor = 
                perspectiveRegistry.findPerspectiveWithId(currentPerspective);
        // after this line, perspectiveDescriptor is still null
        perspectiveDescriptor = perspectiveRegistry
                .clonePerspective(currentPerspective + "." 
                         + label.replaceAll(" ", "_"), label, 
                         currentPerspectiveDescriptor);
        // hence I get a NullPointerException here...
        connectedPerspectives.add(perspectiveDescriptor.getId());
    }
    page.savePerspectiveAs(perspectiveDescriptor);

}

所有其他值似乎都很好

currentPerspectiveDescriptor

是有效对象，

perspectiveRegistry

也是有效对象

标签

类似于

“Connected Perspective 2”

。它还不存在，我创建的透视ID也不存在

---

有什么想法吗？如果

clonePerspective（…）

返回null，这里会出现什么错误？

clonePerspective

在Eclipse4.x中不受支持

这是透视法的代码。clonePerspective：

public IPerspectiveDescriptor clonePerspective(String id, String label,
        IPerspectiveDescriptor desc) throws IllegalArgumentException {
    // FIXME: compat clonePerspective. Not called in 3.8
    E4Util.unsupported("clonePerspective"); //$NON-NLS-1$
    return null;
}

---

Eclipse的错误是

我能够在不重写e4所有内容的情况下，为“克隆”透视图找到一个解决方法。然而，这是一个相当肮脏的黑客行为，我不推荐这样做，因为它对Eclipse的实现类而不是接口使用未经检查的强制转换

@SuppressWarnings("restriction")
public void savePerspectiveAs(String label) {
    IWorkbenchPage page = PlatformUI.getWorkbench()
            .getActiveWorkbenchWindow().getActivePage();
    IPerspectiveDescriptor perspectiveDescriptor = perspectiveRegistry
            .findPerspectiveWithLabel(label);

    // if the perspective doesn't exist, create a new one 
    // by cloning the current perspective
    if (perspectiveDescriptor == null) {
        // Note: this is a dirty hack.
        // It is not recommended to cast to PerspectiveDescriptor 
        // or PerspectiveRegistry.
        PerspectiveDescriptor currentPerspectiveDescriptor =
                (PerspectiveDescriptor) perspectiveRegistry.findPerspectiveWithId(currentPerspective);
        perspectiveDescriptor =
                ((PerspectiveRegistry) perspectiveRegistry)
                        .createPerspective(label, currentPerspectiveDescriptor);
        connectedPerspectives.add(perspectiveDescriptor.getId());
    }

    page.savePerspectiveAs(perspectiveDescriptor);
}

---

它没有抛出异常，而是默默地记录它——这有多重要！有没有办法解决这个问题，或者我们必须等待bug修复？这个bug已经存在两年多了，所以不太可能很快被修复。您可能可以使用Eclipse4EmodelService、EPartService等做一些事情。。。就个人而言，我还没有在e4.FYI中查看透视图：我问过他们，他们告诉我，不幸的是，他们不打算在下一版本中解决这个bug。