Revit二次开发之“改变文件打开时的预览图”

打开文件时，在打开对话框右侧会显示预览图。

默认是显示平面视图的缩略图，下面的代码把Revit文件的预览图修改为三维视图下的缩略图。
来自：http://revit.5d6d.com/thread-1149-1-1.html

[Transaction(TransactionMode.Manual)]
[Regeneration(RegenerationOption.Manual)]
//[Journaling(JournalingMode.NoCommandData)]
public class CmdHi : IExternalCommand
{
    public Result Execute(ExternalCommandData cmdData, ref string message, ElementSet elements)
    {
        UIDocument uiDoc = cmdData.Application.ActiveUIDocument;//base.m_uiDoc
        Selection selection = uiDoc.Selection;

        // Open Revit file
        Document doc = cmdData.Application.Application.OpenDocumentFile(@"D:\Backup\桌面\局部显示.rvt");

        // Create transaction and start
        Transaction trans = new Transaction(doc, "T1");
        trans.Start();

        doc.Regenerate();//重新生成

        // Create thumbnails for preview //设置预览
        DocumentPreviewSettings previewSettings = doc.GetDocumentPreviewSettings();
        //保存选项
        SaveAsOptions saveOpts = new SaveAsOptions();
        //
        // Check for permanent永久 preview view
        if (doc.GetDocumentPreviewSettings().PreviewViewId.Equals(ElementId.InvalidElementId))
        {
            // Access the intial view //文档打开时的预览图
            StartingViewSettings startingViewSettings = StartingViewSettings.GetStartingViewSettings(doc);

            if (!startingViewSettings.ViewId.Equals(ElementId.InvalidElementId))
            {
                // If valid, then set the viewId
                //previewSettings.PreviewViewId 
                //  = startingViewSettings.ViewId;

                saveOpts.PreviewViewId = startingViewSettings.ViewId;
            }
            else
            {
                // Algorithmic approach - look for 3D views

                FilteredElementCollector collector = new FilteredElementCollector(doc).OfClass(typeof(View));

                IEnumerable<View> views
                    = from Autodesk.Revit.DB.View f in collector
                    where (f.ViewType == ViewType.ThreeD && !f.IsTemplate)
                    select f;

                bool bNotFound = true;

                foreach (View vw in views)
                {
                    if (!vw.IsTemplate)
                    {
                        //If we were to set the preview view permanently, 
                        // we would use the following two commented lines
                        //previewSettings.PreviewViewId = vw.Id;
                        //previewSettings.ForceViewUpdate( true );

                        // Set the temporary view
                        saveOpts.PreviewViewId = vw.Id;
                        bNotFound = false;
                        break;
                    }
                }

                // If no 3D view is obtained, look for other valid views
                if (bNotFound)
                {
                    IEnumerable<View> viewsNon3D
                        = from View fNon3D
                        in collector
                        where (fNon3D.ViewType == ViewType.FloorPlan
                            || fNon3D.ViewType == ViewType.EngineeringPlan
                            || fNon3D.ViewType == ViewType.Elevation
                            || fNon3D.ViewType == ViewType.Section
                            && !fNon3D.IsTemplate)
                        select fNon3D;

                    foreach (View vw in viewsNon3D)
                    {
                        if (!vw.IsTemplate)
                        {
                            // If we were to set the preview view permanently, 
                            // we would use the following two commented lines
                            //previewSettings.PreviewViewId = vw.Id;
                            //previewSettings.ForceViewUpdate( true );
                            //设置为3D视图下的预览图
                            saveOpts.PreviewViewId = vw.Id;
                            break;
                        }
                    }
                }
            }
        }

        // Commit transaction
        trans.Commit();

        // Save Revit file to target destination
        doc.SaveAs(@"D:\Backup\桌面\局部显示1.rvt", saveOpts);

        // Close document
        doc.Close();
        return Result.Succeeded;
    }
}

end