public void Update(long roleId, string roleName)
{
using (Dbcontext ctx = new Dbcontext())
{
BaseService <Role> roleBS = new BaseService <Role>(ctx);
bool exists = roleBS.GetAll().Any(r => r.Name == roleName && r.Id != roleId);
if (exists)
{
throw new ArgumentException("角色名字已存在" + roleName);
}
Role role = new Role();
role.Id = roleId;
ctx.Entry(role).State = System.Data.Entity.EntityState.Unchanged;
role.Name = roleName;
ctx.SaveChanges();
}
}