Sharepoint 2010 SPImport.运行安全异常

我想使用SPExport(工作正常)和SPImport将一个web复制到另一个位置。我正在使用Sharepoint Foundation 2010中的应用程序页面。此代码在Button click事件中执行。

using (SPWeb web = site.OpenWeb(sourceWebUrl))
                    {
                        SPExportSettings exportSettings = new SPExportSettings();
                        exportSettings.FileLocation = exportPath;
                        exportSettings.BaseFileName = exportFileName;
                        exportSettings.SiteUrl = site.Url;
                        exportSettings.ExportMethod = SPExportMethodType.ExportAll;
                        exportSettings.FileCompression = true;
                        exportSettings.IncludeVersions = SPIncludeVersions.All;
                        exportSettings.IncludeSecurity = SPIncludeSecurity.All;
                        exportSettings.ExcludeDependencies = false;
                        exportSettings.ExportFrontEndFileStreams = true;
                        exportSettings.OverwriteExistingDataFile = true;
                        SPExportObject expObj = new SPExportObject();
                        expObj.IncludeDescendants = SPIncludeDescendants.All;
                        expObj.Id = web.ID;
                        expObj.Type = SPDeploymentObjectType.Web;
                        exportSettings.ExportObjects.Add(expObj);
                        SPExport export = new SPExport(exportSettings);
                        export.Run();
                    }
 using (SPWeb web = site.OpenWeb(destinationWebUrl))
                    {
                        web.AllowUnsafeUpdates = true;
                        SPImportSettings importSettings = new SPImportSettings();
                        web.FileLocation = exportPath;
                        web.BaseFileName = exportFileName;
                        web.IncludeSecurity = SPIncludeSecurity.All;
                        web.UpdateVersions = SPUpdateVersions.Overwrite;
                        web.RetainObjectIdentity = false;
                        web.SiteUrl = site.Url;
                        web.WebUrl = web.Url;
                        web.Validate();
                        SPImport import = new SPImport(importSettings);
                        import.Run();
                        web.AllowUnsafeUpdates = false;
                    }

异常"此页的安全验证无效。在Web浏览器中单击"返回"，刷新页面，然后再次尝试操作。当调用SPImport.Run()时抛出。

我没能找到解决这个问题的方法，既没有在应用程序页面上添加FormDigest控件，也没有在目标web上允许不安全的更新。

同样，从控制台应用程序运行这段代码工作正常，但如果代码从应用程序页运行，它不工作(即使提高了安全性)。

任何帮助都会很感激。谢谢。

SPUtility.ValidateFormDigest();