Android มีปัญหาเรื่องภาษาไทย กับ php+MSSQL server2008r2 +json ครับ

mssql_query("SET character_set_results=utf-8");
mssql_query("SET character_set_client=utf-8");
mssql_query("SET character_set_connection=utf-8");

$data = iconv("WINDOWS-874","UTF-8",$obResult[$i]);

//2 function of json from http://php.net/manual/fr/function.json-encode.php ...good work :=)
function _json_encode($arr)
{
        //convmap since 0x80 char codes so it takes all multibyte codes (above ASCII 127). So such characters are being "hidden" from normal json_encoding
        array_walk_recursive($arr, function (&$item, $key) { if (is_string($item)) $item = mb_encode_numericentity($item, array (0x80, 0xffff, 0, 0xffff), 'UTF-8'); });
        return mb_decode_numericentity(json_encode($arr), array (0x80, 0xffff, 0, 0xffff), 'UTF-8');

}

function my_json_encode($in) { 
  $_escape = function ($str) { 
    return addcslashes($str, "\v\t\n\r\f\"\\/"); 
  }; 
  $out = ""; 
  if (is_object($in)) { 
    $class_vars = get_object_vars(($in)); 
    $arr = array(); 
    foreach ($class_vars as $key => $val) { 
      $arr[$key] = "\"{$_escape($key)}\":\"{$val}\""; 
    } 
    $val = implode(',', $arr); 
    $out .= "{{$val}}"; 
  }elseif (is_array($in)) { 
    $obj = false; 
    $arr = array(); 
    foreach($in AS $key => $val) { 
      if(!is_numeric($key)) { 
        $obj = true; 
      } 
      $arr[$key] = my_json_encode($val); 
    } 
    if($obj) { 
      foreach($arr AS $key => $val) { 
        $arr[$key] = "\"{$_escape($key)}\":{$val}"; 
      } 
      $val = implode(',', $arr); 
      $out .= "{{$val}}"; 
    }else { 
      $val = implode(',', $arr); 
      $out .= "[{$val}]"; 
    } 
  }elseif (is_bool($in)) { 
    $out .= $in ? 'true' : 'false'; 
  }elseif (is_null($in)) { 
    $out .= 'null'; 
  }elseif (is_string($in)) { 
    $out .= "\"{$_escape($in)}\""; 
  }else { 
    $out .= $in; 
  } 
  return "{$out}"; 
}