Autodesk Developer Network 2011
Autodesk
Create Fill Pattern
§Create and retrieve fill and line patterns
§Apply to a selected surface or grid
§Main classes and methods:
§FillPattern, FillGrid, FillPatternElement.Create(doc, fillPattern)
LinePattern, LinePatternSegment,
LinePatternElement.Create( doc, linePattern) 
fill pattern new.JPG line pattern grid.JPG fill pattern new 2.JPG line pattern new.JPG
This sample demonstrates how to create or retrieve a FillPatternElement or LinePatternElement and apply them to the surface or grid.
To run: open the rvt file provided in the SDK (“CreateFillPattern.rvt”).
Select a wall, and RvtSamples > Elements > Create and set Fill Pattern.  You add fill pattern.