//todo:感觉Application里面不应该提供这么宽泛的接口出去，应该提供的是具体条件的实现
public List <UserDTO> GetUsers(Expression <Func <UserDTO, bool> > spec)
{
Expression <Func <User, bool> > newExpression = ExpressionConvertor <UserDTO, User> .Convert(spec);
IEnumerable <User> users = userRepository.GetAll(newExpression);
return(Mapper.Map <List <User>, List <UserDTO> >(users.ToList()));
}
public void ConvertExpressionTypeTest()
{
Expression <Func <UserDTO, bool> > expression = dto => dto.UserName.Contains("11");
Func <User, bool> newFunc = ExpressionConvertor <UserDTO, User> .Convert(expression).Compile();
User u = new User("111", "password", null);
bool b = newFunc(u);
Assert.IsTrue(b);
u = new User("ert", "password", null);
b = newFunc(u);
Assert.IsTrue(!b);
}