Arcengine Loading Tin data

slightly different from loading other files is that the tin data contains several files , with the following code:

FolderBrowserDialog FolderBrowserDialog = new FolderBrowserDialog ();
if (Folderbrowserdialog.showdialog () ==dialogresult.ok)
{
String filePath = folderbrowserdialog.selectedpath;//Select the Tin folder

String tinpath = Path.getdirectoryname (filePath);//tin folder is in the same path
String tinfilepath = Path.getfilename (filePath);//tin folder name
Iworkspacefactory PWF = new Tinworkspacefactoryclass ();
Iworkspace PW = pwf.openfromfile (tinpath, 0);
Itinworkspace PTW = PW as Itinworkspace;

ITin Ptin = Ptw.opentin (Tinfilepath);
Itinlayer PTL = new Tinlayerclass ();
Ptl.dataset = Ptin;
Axmapcontrol1.addlayer (PTL);

}

Arcengine Loading Tin data