Configure SharePoint site search settings

I came across this requirement, in which i need to configure the site collection level search settings programmatically, so that searching in a site collection will be redirected to custom search page in search center.

Here is what we need to do in case of settings the url via code.

//All URLs are for testing purpose only, please change according your needs

            using (SPSite site = new SPSite("Your site url"))

            {

                using (SPWeb web = site.OpenWeb())

                {

                    web.AllowUnsafeUpdates = true;

                    web.AllProperties["SRCH_ENH_FTR_URL"] = "/sites/search/pages";                    

                   

//For site collection level

                    web.AllProperties["SRCH_SB_SET_SITE"] = "{\"Inherit\":false,\"ResultsPageAddress\":\"/sites/Search/Pages/Results.aspx\",\"ShowNavigation\":false}";                    

                    //For subsite

                    web.AllProperties["SRCH_SB_SET_WEB"] = "{\"Inherit\":false,\"ResultsPageAddress\":\"/sites/Search/Pages/Results.aspx\",\"ShowNavigation\":false}";                    

                    web.Update();

web.AllowUnsafeUpdates = false;

                }

            }

In above code replace the highlighted relative url, to search results page url of your search center.

Once done given url will set as below.