如何避免代码重复

Question

我有以下代码,我想以一种方式编写它,我有最少的代码行,工作以相同的方式完成.我怎样才能做到这一点？

List<Category> categoryList = new List<Category>();
categoryList = Category.LoadForProject(project.ID).ToList();
List<string> categories = new List<string>(Categories);
IList<Category> currentCategories = Category.LoadForProject(project.ID).ToList();
if (currentCategories != null)
{
    foreach (var existingCategories in currentCategories)
    {
        if (categories.Contains(existingCategories.Name))
           categories.Remove(existingCategories.Name);
        else
            existingCategories.Delete(Services.UserServices.User);
    }
    foreach (string item in categories)
    {
        Category category = new Category(project, item.ToString());
        category.Project = project;
        category.Save();
   }
}

---

List<string> priorities = new List<string>(Priorities);
IList<Priority> currentPriorities = Priority.LoadForProject(project.ID).ToList();
if (currentPriorities != null)
{
   foreach (var existingPriorities in currentPriorities)
   {
       if (priorities.Contains(existingPriorities.Name))
           priorities.Remove(existingPriorities.Name);
       else
           existingPriorities.Delete(Services.UserServices.User);
   }
   foreach (string item in priorities)
   {
       Priority priority = new Priority(project, item.ToString());
       priority.Project = project;
       priority.Save();
   }
}

Answer 1

这样的事情应该这样做:

public IList<T> DoYourThing<T>(IList<T> items, IList<T> currentItems, Project project) where T : CommonBaseType
{
  if (currentItems != null)
  {
    foreach (var existingItem in currentItems)
    {
      if (items.Contains(existingItem.Name))
        items.Remove(existingItem.Name);
      else
        existingItems.Delete(Services.UserServices.User);
    }
    foreach (string item in items)
    {
      T newItem = Activator.CreateInstance(typeof(T), new object[] {project, item.ToString()}) as T;
      newItem.Project = project;
      newItem.Save();
    }
  }

  return currentItems;
}

然后你可以像这样调用它:

var currentCategories = DoYourThing(Categories.ToList(), Category.LoadForProject(project.ID).ToList());
var currentProjects = DoYourThing(Priorities.ToList(), Priority.LoadForProject(project.ID).ToList());

最后,您应该特别注意两件事:首先,函数有一个通用条件where T : CommonBaseType.我假设Category和Project有一个包含Name的公共基类型或接口.如果没有,你应该摆脱条件,并使用动态来获取名称.

其次,我正在使用Activator.Create为您创建类.如果你不知道这个伎俩,这是很难弄清楚的棘手部分

祝好运!

Answer 2

使优先级和类别实现相同的接口或派生自具有公共属性的类(即.Project,.Name和.Save).然后使用该接口或基类作为函数的类型,您将能够将两个类的集合传递给它.