How can I convert from ITM ref (Israel new map) to GPS ref and from GPS ref to ITM ref?
I need any C# sample code or formula for this.
For example: 32.086156,34.769239 = 178364,665948
Or : 29.548783,34.952316 = 194997,384546
By 'GPS ref' I'll take it you mean WGS84 based geographic coordinates. ITM looks to be EPSG:2039 on spatialreference.org, which includes the ESRI WKT. From your tags, it sounds like you're trying to do this transformation within ArcGIS, which can be accomplished using the ESRI WKT and something like the C# Projection Engine wrapper.
There's a C# wrapper for Proj.4 which could also be used. Here's the conversion done interactively with GDAL using Proj.4: