Conver the code of php in c#

Question

class mytest extends Controller {

public function index(){

//CREATE A FILE

//generate random filename

$hash = strtoupper(md5(rand()));

$random_name = substr($hash, rand(0, 22),8);

//get random file from directory

$list = openDerictory("someplace/sdfs");

$randomFile = $list[array_rand($list)];

appendToFile("someplace/sdfs",$randomFile, $random_name);

///DO RANDOM THINGS

var $t = 'sdfs';

foreach($list as $item){

echo $t . $item;

}

//LET THE USER KNOW SOMETHING

echo "this is a test";

echo "we did somtyhing";

echo "try something else";

}

//Function to open Directory

function openDerictory($path, $type= ".txt")

{

$list = array();

if ($dh = opendir($path)) {

$count = 0;

while (($file = readdir($dh)) !== false) {

$info = pathinfo($path . $file);

if(strtolower($info['extension']) == strtolower($type)){

$list[$count] = $file;

$count++;

}

}

closedir($dh);

}

return  $list;

}

function appendToFile($path ,$randomFile, $random_name)

{

//get contents

$file = file_get_contents($path . $randomFile, FILE_USE_INCLUDE_PATH);

//savefile

$fp = fopen($path . $random_name . 'ext','a');

fwrite($fp, $file);

fclose($fp);

}

}