Question

我有一份客户清单,根据用户选择,可在1至6个领域进行分类。任何领域都可以有秩序。如果我知道前面的领域和顺序,分类便容易:

customers = customers
                .OrderBy(c => c.LastName)
                .ThenBy(c => c.City)
                .ThenBy(c => c.Age).ToList();

我如何在业余的田间通行? 是否有办法这样做?

    string sortField1 = "State";
    string sortField2 = "City";
    string sortField3 = "Type";

    customers = customers
                .OrderBy(c => c.sortField1)
                .ThenBy(c => c.sortField2)
                .ThenBy(c => c.sortField3).ToList();

Answer 1

我通过链条解决这一问题。 OrderBy statement in a ForEach loop. 我的Linq问询中附有用户选择的每一种标准。我把我的名单归纳在一份可贵的文件中,能够看到林克的盘点。

IQueryable<CustomerMaster> query = customers.AsQueryable();

            // reverse the sort order (sorts are applied incrementally) 
            // We need the user s last
            // sort criteria to get applied first
            sortOrder.Reverse();

            foreach (var sortItem in sortOrder)
            {
                switch (sortItem)
                {
                    case "LName":
                        query = query.OrderBy(c => c.LName);
                        break;

                    case "State":
                        query = query.OrderBy(c => c.State);
                        break;

                    default:
                        query = query
                            .OrderBy(c => c.LName)
                            .ThenBy(c => c.State);
                        break;
                }
            }
            customers = query.ToList();
            // set the sortorder back to user s order
            sortOrder.Reverse();
        }

Resulting query:

query = {System.Collections.Generic
        .List`1[CustomerMaster]
        .OrderBy(c => c.LName)
        .OrderBy(c => c.State)}

Answer 2

查阅, 用于指导如何在操作时间建立动态的LinQ查询。这应该是你所期待的。

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