public Task AddToRoleAsync(IdentityUser user, string roleName)
{
ThrowIfDisposed();
if (user == null)
{
throw new ArgumentNullException("user");
}
if (string.IsNullOrWhiteSpace(roleName))
{
throw new ArgumentNullException("roleName");
}
return(Task.Run(() =>
{
int roleId = UsersDb.IdentityRoles.Where(r => r.Name == roleName).Select(r => r.Id).Single();
UsersDb.InsertWithIdentity(new IdentityUserInRole()
{
UserId = user.Id, RoleId = roleId
});
}));
}