如何重構此C＃代碼以使其更易於閱讀？

Question

這是我的控制器中的一個動作 - 我的控制器在整個項目中都有類似的大方法。

我想知道在哪里放這些東西以及如何清理東西。 我是新手，如果我看到如何更改我自己的代碼的一個很好的例子，它可能會教我如何對我的大量代碼進行操作。

這是我的行動：

public ActionResult Index(string sortOrder, string currentFilter, string searchString, int? page)
{
    ViewBag.CurrentSort = sortOrder;
    ViewBag.TitleSortParm = String.IsNullOrEmpty(sortOrder) ? "Title desc" : "";
    ViewBag.CreditsSortParm = sortOrder == "Credits" ? "Credits desc" : "Credits";
    ViewBag.ElectiveSortParm = sortOrder == "Elective" ? "Elective desc" : "Elective";
    ViewBag.InstructorSortParm = sortOrder == "Instructor" ? "Instructor desc" : "Instructor";
    ViewBag.YearSortParm = sortOrder == "Year" ? "Year desc" : "Year";
    ViewBag.AttendingDaysSortParm = sortOrder == "AttendingDays" ? "AttendingDays desc" : "AttendingDays";
    ViewBag.AttendanceCapSortParm = sortOrder == "AttendanceCap" ? "AttendanceCap desc" : "AttendanceCap";
    ViewBag.StartDateSortParm = sortOrder == "StartDate" ? "StartDate desc" : "StartDate";
    ViewBag.LocationSortParm = sortOrder == "Location" ? "Location desc" : "Location";
    ViewBag.ParishSortParm = sortOrder == "Parish" ? "Parish desc" : "Parish";
    ViewBag.DescriptionSortParm = sortOrder == "Description" ? "Description desc" : "Description";
    ViewBag.ApprovedSortPArm = sortOrder == "Approved" ? "Approved desc" : "Approved";
    ViewBag.CompletedSortPArm = sortOrder == "Completed" ? "Completed desc" : "Completed";
    ViewBag.ArchivedSortPArm = sortOrder == "Archived" ? "Archived desc" : "Archived";

    if (Request.HttpMethod == "GET")
    {
        searchString = currentFilter;
    }
    else
    {
        page = 1;
    }
    ViewBag.CurrentFilter = searchString;

    var courses = from s in db.Courses
                    select s;
    if (!String.IsNullOrEmpty(searchString))
    {
        courses = courses.Where(s => s.Title.ToUpper().Contains(searchString.ToUpper()));
    }
    switch (sortOrder)
    {
        case "Title desc":
            courses = courses.OrderByDescending(s => s.Title);
            break;
        case "Credits":
            courses = courses.OrderBy(s => s.Credits);
            break;
        case "Credits desc":
            courses = courses.OrderByDescending(s => s.Credits);
            break;
        case "Elective":
            courses = courses.OrderBy(s => s.Credits);
            break;
        case "Elective desc":
            courses = courses.OrderByDescending(s => s.Credits);
            break;
        case "Instructor":
            courses = courses.OrderBy(s => s.Instructor.LastName);
            break;
        case "Instructor desc":
            courses = courses.OrderByDescending(s => s.Instructor.LastName);
            break;
        case "Year":
            courses = courses.OrderBy(s => s.Year);
            break;
        case "Year desc":
            courses = courses.OrderByDescending(s => s.Year);
            break;
        case "AttendingDays":
            courses = courses.OrderBy(s => s.AttendingDays);
            break;
        case "AttendingDays desc":
            courses = courses.OrderByDescending(s => s.AttendingDays);
            break;
        case "AttendanceCap":
            courses = courses.OrderBy(s => s.AttendanceCap);
            break;
        case "AttendanceCap desc":
            courses = courses.OrderByDescending(s => s.AttendanceCap);
            break;
        case "StartDate":
            courses = courses.OrderBy(s => s.StartDate);
            break;
        case "StartDate desc":
            courses = courses.OrderByDescending(s => s.StartDate);
            break;
        case "Location":
            courses = courses.OrderBy(s => s.Location);
            break;
        case "Location desc":
            courses = courses.OrderByDescending(s => s.Location);
            break;
        case "Parish":
            courses = courses.OrderBy(s => s.Parish);
            break;
        case "Parish desc":
            courses = courses.OrderByDescending(s => s.Parish);
            break;
        case "Description":
            courses = courses.OrderBy(s => s.Description);
            break;
        case "Description desc":
            courses = courses.OrderByDescending(s => s.Description);
            break;
        case "Approved":
            courses = courses.OrderBy(s => s.Approved);
            break;
        case "Approved desc":
            courses = courses.OrderByDescending(s => s.Approved);
            break;
        case "Completed":
            courses = courses.OrderBy(s => s.Completed);
            break;
        case "Completed desc":
            courses = courses.OrderByDescending(s => s.Completed);
            break;
        case "Archived":
            courses = courses.OrderBy(s => s.Archived);
            break;
        case "Archived desc":
            courses = courses.OrderByDescending(s => s.Archived);
            break;
        default:
            courses = courses.OrderBy(s => s.Title);
            break;
    }
    int pageSize = 4;
    int pageNumber = (page ?? 1);
    return View(courses.ToPagedList(pageNumber, pageSize));
}

我應該怎么做以上代碼，使其更具可讀性？ 我是否只是將其中的一部分作為單獨的方法移動並將它們移動到控制器的底部？ 我是否將這些方法放在另一個文件中並在此處引用它？

請記住我正在學習，並且享受清晰度。

Answer 1

如何更改代碼將完全是主觀的，這是一個創造性的過程，你需要通過感覺和戰斗來成為一個更好的開發人員。

但作為偽代碼示例，對象是使您的方法變小。 不，真的，甚至更小！

使函數名稱非常有意義，並確保它們告訴程序員方法的真正意圖。 這只是結構的一個例子：

public class Something {

   public ActionResult Index() {
       MakeCallToFunction();
       var something = GetSomething();
       var somethingElse = GetSomethingElse(something);
       var model = new SomeViewModel(somethingElse);
       return View(model);
   }

   private void MakeCallToFunction () {
       ...
   }

   private string GetSomething() {
       ...
       return someVal;
   }

   private SomeObject GetSomethingElse(string something) {
       ...
       return someBigObject;
   }
}

或者它可能意味着你接受所有這些小功能並上課

public class Something {

   public ActionResult Index(int id) {
       var model = new SomeRelatedStuff.Load(id);
       return View(model);
   }
}

private class SomeRelatedStuff {

   public SomeRelatedStuff()

   public static SomeRelatedStuff Load(int id) {
       var something = GetSomething();
       var somethingElse = GetSomethingElse(something);
       var model = new SomeViewModel(somethingElse);
       MakeObject();
       return this;
   }

   private string GetSomething() {
       ...
       return someVal;
   }

   private SomeObject GetSomethingElse(string something) {
       ...
       return someBigObject;
   }

   private void MakeObject () {
       ...
   }

}

作為附注，請請羅伯特·馬丁（鮑勃叔叔）獲取清潔代碼，至少閱讀本周末的前4章。 然后再讀一遍。

Answer 2

首先，擺脫你的魔法弦。 將排序順序設為枚舉，如下所示：

public enum ActionSortOrder {
    Credits,
    Elective,
    ...
}

ActionSortOrder order = ActionSortOrder.Credits;

這比使用未定義的字符串更易於管理，如果其功能需要一些解釋，您可以記錄枚舉成員。

其次，方法頂部的線條有些令人困惑：

 ViewBag.CreditsSortParm = sortOrder == "Credits" ? "Credits desc" : "Credits";

因此，如果您將“Credits”作為排序順序傳遞，則默認為降序排列？ 如果你不這樣做，它默認為升序？ 為什么？ 為什么不給出升序/降序的選項（再次使用枚舉而不是魔術字符串）？ 為什么每次調用此方法時都會保存所有這些排序順序？ 這些設定變量在哪里使用？ 您只能使用此方法中傳遞的順序。

此外，不要擔心開關看起來很大。 Switch語句通常僅用於避免一堆if-else語句。 因此大多數交換機在實踐中都有相當多的情況。

了解有關代碼的更多信息有助於評估它。