microsoft graph - 无法在Sharepoint的网站页面上获取Webpart

通过CSOM使用以下代码，我无法在Sharepoint中获取页面的Web部件。

Microsoft.SharePoint.Client.File oFile = this._ClientContext.Web.GetFileByServerRelativeUrl(myurl );
                LimitedWebPartManager limitedWebPartManager = oFile.GetLimitedWebPartManager(PersonalizationScope.Shared);
                this._ClientContext.Load(limitedWebPartManager.WebParts,
                 wps => wps.Include(
                 wp => wp.WebPart.Title,
                 wp => wp.Id,
                 wp => wp.WebPart.ExportMode,
                 wp => wp.WebPart.TitleUrl,
                 wp => wp.WebPart.Properties
                 ));
                this._ClientContext.Load(limitedWebPartManager.WebParts);
                this._ClientContext.ExecuteQuery();
                var areItemsavail = limitedWebPartManager.WebParts.AreItemsAvailable;
                var webpartcount = limitedWebPartManager.WebParts.Count;

在areItemsavail上面显示true，而webpartcount示出的值0。
专用页面上有很多Web部件可用。
有什么方法可以webparts使用CSOM在Sharepoint网站页面上获取/获取？