c# - 如何消除重复代码？

Question

我有以下代码，我想以一种代码重复最少的方式编写它。

if (Categories != null)
{
    bool flag=false;
    foreach (dynamic usableCat in Category.LoadForProject(project.ID))
    {
        foreach (dynamic catRow in Categories)
        {
            if (usableCat.ID == catRow.ID)
                flag = true;                            
        }
        if (!flag)
        {
            int id = usableCat.ID;
            Category resolution = Category.Load(id);
            resolution.Delete(Services.UserServices.User);
        }
    }
}
if (Priorities != null)
{
    bool flag = false;
    foreach (dynamic usableCat in Priority.LoadForProject(project.ID))
    {
        foreach (dynamic catRow in Priorities)
        {
            if (usableCat.ID == catRow.ID)
                flag = true;
        }
        if (!flag)
        {
            int id = usableCat.ID;
            Priority resolution = Priority.Load(id);
            resolution.Delete(Services.UserServices.User);
        }
    }
}

请注意，Category 和 priority 没有包含 ID 的公共(public)基类型或接口(interface)。

Answer 1

void DeleteUsable<Ttype>(IEnumerable<Ttype> usables, IEnumerable<Ttype> collection, Func<int, Ttype> load)
{
     bool flag = false;
     foreach (dynamic usableCat in usables)
                {
                    foreach (dynamic catRow in collection)
                    {
                        if (usableCat.ID == catRow.ID)
                            flag = true;
                    }
                    if (!flag)
                    {
                        int id = usableCat.ID;
                        Ttype resolution = load(id);
                        resolution.Delete(Services.UserServices.User);
                    }
                }
}

编辑:调用它:

if (Categories != null) 
   DeleteUsable(Category.LoadForProject(project.ID), Categories, Categoriy.Load); 
if (Priorities != null) 
   DeleteUsables(Priority.LoadForProject(project.ID), Priorities, Priority.Load);