Passing multiple Id parameter to Web Api GET or DELETE request

Map your route like below will allow you to pass two parameter, you can add more that two parameter this way

    [HttpGet]
    [Route("api/item/{id1}/{id2}")]
    [ResponseType(typeof(UserItem))]
    public async Task<IHttpActionResult> GetUserItem(string id1, string id2)
    {
       UserItem item = await db.useritems.FindAsync(id1);
       ......
    }