现有PHP代码，需要修改成ASP.NET网页代码，寻求帮助~

<?php



$charId = $_POST['char_id'];

$nameServer =$_POST['name_server'];

$uiLoadSuccess =$_POST['ui_load_success'];

$group = substr($charId, -3);

$file_tmp = $_FILES["ui"]["tmp_name"];



$target_dir = "ui/" . $nameServer ."/" .$group ."/";

$target_file = $target_dir . basename($_FILES["ui"]["name"]);



if(!is_dir($target_dir)){

	mkdir($target_dir, 0755, true);

	} 



    if (move_uploaded_file($_FILES["ui"]["tmp_name"], $target_file)) {

        echo "The file ". basename( $_FILES["ui"]["name"]). " has been uploaded.";

    } else {

        echo "Sorry, there was an error uploading your file.";

    }



?>

using Aura.Shared.Util;

using Swebs;

using Swebs.RequestHandlers.CSharp;

using System;

using System.Text.RegularExpressions;



public class UiStorageController : Controller

{

	public override void Handle(HttpRequestEventArgs args, string requestedPath, string localPath)

	{

		var request = args.Request;

		var response = args.Response;



		response.ContentType = "text/plain";



		// Get file

		var file = request.File("ui");

		if (file == null)

		{

			Log.Debug("UiStorageController: Missing file.");

			return;

		}



		// Check file name

		if (!Regex.IsMatch(file.FileName, @"^[0-9]{16}\.xml$"))

		{

			Log.Debug("UiStorageController: Invalid file name '{0}'.", file.FileName);

			return;

		}



		var charId = request.Parameter("char_id", null);

		var serverName = request.Parameter("name_server", null);

		var loadSuccess = request.Parameter("ui_load_success", null);



		// Check parameters

		if (!Regex.IsMatch(charId, @"^[0-9]{16}$") || !Regex.IsMatch(charId, @"^[0-9A-Za-z_ ]+$"))

		{

			Log.Debug("UiStorageController: Invalid character id ({0}) or server name ({1}).", charId, serverName);

			return;

		}



		var group = charId.Substring(charId.Length - 3);



		// Move file

		try

		{

			file.MoveTo("user/web/upload/ui/" + serverName + "/" + group + "/" + file.FileName);

		}

		catch (Exception ex)

		{

			Log.Exception(ex, "UiStorageController: Failed to move file.");

		}



		// Success

		response.Send("1");

	}

}