ASP. NET paging navigation bar

Protected static string paging (INT pageindex, int pagecount) {string url = httpcontext. Current. Request. rawurl; If (URL. indexof ("? ")! =-1) {If (URL. lastindexof ("? Page ")! =-1) {url = URL. substring (0, URL. lastindexof ('? '); Url + = "? ";}Elseurl + =" & ";}else {URL + = "? ";} Pageindex = typeconverter. strtoint (httpcontext. current. request. querystring ["page"]. tostring (); int start = 1; int end = 5; int Prev = 0; int next = 0; stringbuilder html = new stringbuilder (); If (pageindex <1) // page number {pageindex = 1;} If (pageindex> pagecount) // total page number {pageindex = pagecount;} next = pageindex + 1; Prev = pageindex-1; if (pageindex> 3) {start = pageindex-2; end = pageindex + 2;} If (start <1) {start = 1;} // to avoid negative output, set if the value is smaller than the value, if (pagecount <End) {end = pagecount ;} if (pageindex> 1) {HTML. appendline ("<a href = \" "+ URL +" page = 1 \ "> homepage </a>"); html. appendline ("<a href = \" "+ URL +" page = "+ Prev +" \ "> previous page </a>") ;}for (INT I = start; I <= end; I ++) {If (pageindex = I) HTML. appendline ("<span> <a href = \" "+ URL +" page = "+ I. tostring () + "\"> "+ I. tostring () + "</a> </span>"); elsehtml. appen Dline ("<a href = \" "+ URL +" page = "+ I. tostring () + "\"> "+ I. tostring () + "</a>");} If (pageindex! = Pagecount) {HTML. appendline ("<a href = \" "+ URL +" page = "+ next +" \ "> next page </a>"); html. appendline ("<a href = \" "+ URL +" page = "+ pagecount +" \ "> last page </a>");} return HTML. tostring ();}