Create a raster catalog using the geoprocessor
CreateRasterCatalog_GP.cs
// Copyright 2012 ESRI
// 
// All rights reserved under the copyright laws of the United States
// and applicable international laws, treaties, and conventions.
// 
// You may freely redistribute and use this sample code, with or
// without modification, provided you include the original copyright
// notice and use restrictions.
// 
// See the use restrictions.
// 

using System;
using System.Collections.Generic;
using System.Text;
using ESRI.ArcGIS.DataSourcesGDB;
using ESRI.ArcGIS.DataSourcesRaster;
using ESRI.ArcGIS.Geodatabase;
using ESRI.ArcGIS.Geometry;
using ESRI.ArcGIS.Geoprocessing;
using ESRI.ArcGIS.DataManagementTools;
using ESRI.ArcGIS.Geoprocessor;
using ESRI.ArcGIS.esriSystem;


namespace CreateRasterCatalogs
{
    class CreateRasterCatalogApp
    {       
        //Set variables
        static string sdePath = @"Database Connections\Connection to tiny.sde";
        static string rasterFolder = @"C:\Temp\data";
        static string catalogName = "rc_1";
        static string outRC =  sdePath + "\\" + catalogName;

        static void Main(string[] args)
        {

            #region Initialize the license 
                ESRI.ArcGIS.esriSystem.AoInitialize aoInit = null;
                try
                {
                    Console.WriteLine("Obtaining license");
                    ESRI.ArcGIS.RuntimeManager.Bind(ESRI.ArcGIS.ProductCode.Desktop);
                    aoInit = new AoInitializeClass();
                    esriLicenseStatus licStatus = aoInit.Initialize(esriLicenseProductCode.esriLicenseProductCodeStandard);
                    Console.WriteLine("Ready with license.");
                }
                catch (Exception exc)
                {
                    // If it fails at this point, shutdown the test and ignore any subsequent errors.
                    Console.WriteLine(exc.Message);
                }
            #endregion


            //Coordinate system for raster column
            IGPCoordinateSystem rSR = new GPCoordinateSystemClass();
            rSR.SpatialReference = CreateSpatialReference((int)esriSRProjCSType.esriSRProjCS_World_Mercator);
            //Coordinate system for geometry column
            IGPSpatialReference gSR = new GPSpatialReferenceClass();
            gSR.SpatialReference = CreateSpatialReference((int)esriSRProjCSType.esriSRProjCS_World_Mercator);

            //Creates raster catalog
            CreateRasterCatalog_GP(rSR, gSR);

            //Loads rasters in the given directory to raster catalog
            LoadDirToRasterCatalog(outRC, rasterFolder);
            System.Console.WriteLine("Loading completed");

            System.Console.ReadLine();//waiting user to click a key to finish

           //Do not make any call to ArcObjects after license is shut down.
            aoInit.Shutdown();
        }

        //Creates raster catalog using GP CreateRasterCatalog class
        static void CreateRasterCatalog_GP(object rasterCoordSys, object geometryCoordsys)
        {
            //Initialize GeoProcessor
            ESRI.ArcGIS.Geoprocessor.Geoprocessor geoProcessor = new ESRI.ArcGIS.Geoprocessor.Geoprocessor();

            //CreateRasterCatalog GP tool
            CreateRasterCatalog createRasterCatalog = new CreateRasterCatalog();

            //Set parameters
            createRasterCatalog.out_path = sdePath;
            createRasterCatalog.out_name = catalogName;
            createRasterCatalog.raster_spatial_reference = rasterCoordSys;
            createRasterCatalog.spatial_reference = geometryCoordsys;

            //Execute the tool to create a raster catalog
            geoProcessor.Execute(createRasterCatalog, null);
            ReturnMessages(geoProcessor);
        }

        //GP message handling
        private static void ReturnMessages(Geoprocessor gp)
        {
            if (gp.MessageCount > 0)
            {
                for (int Count = 0; Count <= gp.MessageCount - 1; Count++)
                {
                    Console.WriteLine(gp.GetMessage(Count));
                }
            }
        }

        static void LoadDirToRasterCatalog(string outRasterCatalog, string inputDir)
        {
            //Initialize GeoProcessor
            ESRI.ArcGIS.Geoprocessor.Geoprocessor geoProcessor = new ESRI.ArcGIS.Geoprocessor.Geoprocessor();

            //Set parameters
            IVariantArray parameters = new VarArrayClass();

            //Set input folder
            parameters.Add(inputDir);

            //Set target GDB raster catalog
            parameters.Add(outRasterCatalog);

            //Execute the tool to load rasters in the directory to raster catalog
            geoProcessor.Execute("WorkspaceToRasterCatalog", parameters, null);
            ReturnMessages(geoProcessor);
        }

        //Create a spatial reference with given factory code
        static ISpatialReference CreateSpatialReference(int code)
        {
            ISpatialReferenceFactory2 spatialReferenceFact = new SpatialReferenceEnvironmentClass();
            try
            {
                return spatialReferenceFact.CreateSpatialReference(code);
            }
            catch
            {
                return new UnknownCoordinateSystemClass();
            }
        }
    }

}