在CefSharp中完成下载

我尝试使用CefSharp为网站制作一个小的下载工具。为了下载文件，我使用了CefSharp提供的很好的示例DownloadHandler。现在，我想在下载完成后做一些事情。我知道 downloadItem 具有一个 IsComplete 值。但是，如果我在 OnDownloadUpdated 方法中放入这样的内容，则将永远不会执行

I try do make a small downloader-tool for a website with CefSharp. For downloading files, I use the pretty well example DownloadHandler from CefSharp. Now, I want to do some things after the download is finished. I know the "downloadItem" has a "IsComplete" value. But if I put something like this in the "OnDownloadUpdated" method, stuff will never be executed

        if (downloadItem.IsComplete) {
            //do stuff
        }

，我的问题是，我必须在哪里检查下载的项目是否已完成？

So, my question is, where I have to check if my downloaded item is completed?

编辑：完成DownloadHandler：

Complete DownloadHandler:

    public class DownloadHandler : IDownloadHandler {

    public event EventHandler<DownloadItem> OnBeforeDownloadFired;
    public event EventHandler<DownloadItem> OnDownloadUpdatedFired;
    private bool stop;
    private DownloadWindow window;

    public void OnBeforeDownload(IBrowser browser, DownloadItem downloadItem, IBeforeDownloadCallback callback) {
        var handler = OnBeforeDownloadFired;
        if (handler != null) {
            handler(this, downloadItem);
        }

        if (!callback.IsDisposed) {
            using (callback) {
                callback.Continue(downloadItem.SuggestedFileName, showDialog: true);
            }
        }
        window = new DownloadWindow(downloadItem.TotalBytes, downloadItem.SuggestedFileName, this);
        window.Show();
    }

    public void OnDownloadUpdated(IBrowser browser, DownloadItem downloadItem, IDownloadItemCallback callback) {
        var handler = OnDownloadUpdatedFired;
        if (handler != null) {
            handler(this, downloadItem);
        }

        if (window != null) {
            window.UpdateProgress(downloadItem.ReceivedBytes);
        }

        if (stop) {
            callback.Cancel();
        }
    }

    public void StopDownload() {
        stop = true;
    }
}