如何优化我的 if else 代码 c#

Question

我有以下代码：

TryUpdateModel(model);
            if (ModelState.IsValid && model.FullNameIsChecked == true && model.LookingFor == null)
            {
                model.ContactList = contactRepository.GetAll(filter: x => x.UserId == user.Id);
                model.ContactList.Sort((x, y) => string.Compare(x.FullName, y.FullName));
            }
            else if (ModelState.IsValid && model.FullNameIsChecked == false && model.LookingFor == null)
            {
                model.ContactList = contactRepository.GetAll(filter: x => x.UserId == user.Id);
                model.ContactList.Sort((x, y) => string.Compare(x.Email, y.Email));
            }
            else if (ModelState.IsValid && model.LookingFor != null && model.FullNameIsChecked == true)
            {
                model.ContactList = contactRepository.GetAll(filter: x => x.UserId == user.Id);
                model.ContactList = contactRepository.GetAll(filter: x => x.FullName.Contains(model.LookingFor));
                model.ContactList.OrderBy(f => f.FullName);
            }
            else if (ModelState.IsValid && model.LookingFor != null && model.FullNameIsChecked == false)
            {
                model.ContactList = contactRepository.GetAll(filter: x => x.UserId == user.Id);
                model.ContactList = contactRepository.GetAll(filter: x => x.Email.Contains(model.LookingFor));
                model.ContactList.OrderBy(e => e.Email);
            }
            else
            {
                model.ContactList = contactRepository.GetAll(filter: x => x.UserId == user.Id);
            }

我正在使用带有 Razor 引擎的 .NET MVC 5，并使用上面的代码进行排序操作。我可以优化我的 If else 部分代码吗？我唯一想到的是使用 switch - case operator 但它看起来几乎相似。 提前致谢

Answer 1

你所有的案例都适合这个：

//Place this here since it's non conditional
model.ContactList = contactRepository.GetAll(filter: x => x.UserId == user.Id);


if(ModelState.IsValid)
{
    if(model.LookingFor == null)
    {
        if(model.FullNameIsChecked){
            //...
        }else
        {
            //...
        }
    }else
    {
        if(model.FullNameIsChecked){
            //...
        }else
        {
            //...
        }
    }
}
else
{
    //... Actually you don't need this case...
}

Answer 2

• 我在你的代码检查状态中看不到 ModelState 的任何用途

• if条件下不需要比较bool， 即

  if(true)
  

  与

  相同

  if(bool variable=true)
  

• 使用String.IsNullOrEmpty检查null

   TryUpdateModel(model);
  
    model.ContactList = contactRepository.GetAll(filter: x => x.UserId == user.Id);
  
          if(  String.IsNullOrEmpty(model.LookingFor))
          {
              if(model.FullNameIsChecked)
              {
                  model.ContactList.Sort((x, y) => string.Compare(x.FullName, y.FullName));
              }
              else
              {
                  model.ContactList.Sort((x, y) => string.Compare(x.Email, y.Email));
              }
          }
          else
          {
              if(model.FullNameIsChecked)
              {
                 model.ContactList = contactRepository.GetAll(filter: x => x.FullName.Contains(model.LookingFor));
                 model.ContactList.OrderBy(f => f.FullName);
              }
              else
              {
                 model.ContactList = contactRepository.GetAll(filter: x => x.UserId == user.Id);
                 model.ContactList = contactRepository.GetAll(filter: x => x.Email.Contains(model.LookingFor));
              }
          }
  

Answer 3

当model.LookingFor 不为空时，您调用contactRepository.GetAll() 两次。第一次打给contactRepository.GetAll(filter: x => x.UserId == user.Id) 是多余的，对吧？

有时您拨打.Sort()，有时您拨打.OrderBy()。为什么不一致？

您已将x、f 和e 用作虚拟变量。我建议始终使用一些虚拟变量——也许c 用于“联系人”。

无论如何，这段代码想要做某种GetAll()，然后可能是排序。所以，让我们写一个对GetAll() 的调用和一个对OrderBy() 的调用。

TryUpdateModel(model);
model.ContactList = contactRepository.GetAll(filter:
    !ModelState.IsValid ?      (c => c.UserId == user.Id) :
    model.LookingFor == null ? (c => c.UserId == user.Id) :
    model.FullNameIsChecked ?  (c => c.FullName.Contains(model.LookingFor)) :
                               (c => c.Email.Contains(model.LookingFor))
);
if (ModelState.IsValid)
{
    model.ContactList.OrderBy(model.FullNameIsChecked ?
        (c => c.FullName) : (c => c.Email)
    );
}

Answer 4

TryUpdateModel(model);
if(ModelState.IsValid)
{
  model.ContactList = contactRepository.GetAll(filter: x => x.UserId == user.Id);
  if(model.LookingFor == null)
  {
        if(model.FullNameIsChecked)
        {
             model.ContactList.Sort((x, y) => string.Compare(x.FullName, y.FullName));
        }
        else
        {
             model.ContactList.Sort((x, y) => string.Compare(x.Email, y.Email));
        }
  }
  else
  {
        if(model.FullNameIsChecked)
        {
            model.ContactList = contactRepository.GetAll(filter: x => x.FullName.Contains(model.LookingFor));
            model.ContactList.OrderBy(f => f.FullName);
        }
        else
        {
            model.ContactList = contactRepository.GetAll(filter: x => x.Email.Contains(model.LookingFor));
            model.ContactList.OrderBy(e => e.Email);
        }
  }
}

Answer 5

erm，这样每个条件都只检查一次。

if (ModelState.IsValid)
{
    if (string.IsEmptyOrWhitespace(model.LookingFor))
    {
        model.ContactList = contactRepository.GetAll(filter: x => x.UserId == user.Id);
    }
    else
    {
        model.ContactList = contactRepository.GetAll(
                filter: x => x.FullName.Contains(model.LookingFor));
    }

    if(model.FullNameIsChecked)
    {
        model.ContactList.OrderBy(f => f.FullName);
    }
    else
    {
        model.ContactList.OrderBy(e => e.Email); 
    }
}
else
{
    model.ContactList = contactRepository.GetAll(filter: x => x.UserId == user.Id);
}