C++ 从POCO DirectoryWatcher接收到重复事件

我试图使用POCO文件系统库中的DirectoryWatcher类来监视特定文件夹的更改。代码非常简单，如下所示：

Monitor::Monitor() {
    pattern = new Glob("/path/to/dir/*.dat",
                       Glob::GLOB_DOT_SPECIAL);

    watcher = new DirectoryWatcher(std::string("/path/to/dir"));

    watcher->itemAdded += delegate(this, &Monitor::onFileAdded);
    watcher->itemModified += delegate(this, &Monitor::onFileChanged);
}

void Monitor::onFileAdded(const DirectoryWatcher::DirectoryEvent& addEvent) {
    if (pattern->match(addEvent.item.path())) {
        std::cout << "File added: " << addEvent.item.path() << std::endl;
    }
}

void Monitor::onFileChanged(const DirectoryWatcher::DirectoryEvent& changeEvent) {
    if (pattern->match(changeEvent.item.path())) {
        std::cout << "File changed: " << changeEvent.item.path() << std::endl;
    }
}

Monitor:：Monitor（）{
pattern=newglob（“/path/to/dir/*.dat”，
Glob：：Glob_DOT_SPECIAL）；
watcher=newdirectorywatcher（std:：string（“/path/to/dir”）；
观察者->项目添加+=委托（此，&监视器：：未引导）；
观察者->项目修改+=委托（此，&Monitor:：onFileChanged）；
}
无效监视器：：onfiled（const DirectoryWatcher：：DirectoryEvent和addEvent）{
if（模式->匹配（addEvent.item.path（））{
标准：：cout