I'm trying to create a tab on the FeatureMgr and having huge problems - for an add-in using C# (solidworks 2014).

The CreateFeatureMgrWindowFromHandle method doesn't seem to work - it always returns null. The example given at http://help.solidworks.com/2012/english/api/sldworksapi/add_.net_controls_to_solidworks_using_an_add-in_example_csharp.htm behaves in the same way. Using CreateFeatureMgrWindowFromHandlex64 is the same.

Using it just like in the sample code:

FeatureMgrControl = new Form1();     // this works; control also works with DisplayWindowFromHandle of ITaskpaneView

IFeatMgrView swFeatMgrTabTop = swModelViewMgr.CreateFeatureMgrWindowFromHandle(cmdGroup.SmallIconList, (int)FeatureMgrControl.Handle.ToInt64(), "MyDotNetControl", (int)swFeatMgrPane_e.swFeatMgrPaneTop);     // always returns null even with the x64 version

The method CreateFeatureMgrView2 of IModelViewManager also doesn't work and always returns null.The only thing working somehow is the "obsolete" CreateFeatureMgrView3 method of IModelDoc2 which works for top & bottom (but not for flyout).

Couldn't get any of the ActiveX code working since I don't have the calendar control to compare against and all the CreateFeatureMgrControl3 calls I've tried with various controls also failed.

Any help much appreciated!