共享一个用反射实现的任意实体类之间的数据“复制或合并”代码（十行以内），控制非常的灵活~~~

wtoeb 2015-12-27 10:38:07

加精

1、说明：
string[] reqItems是需要复制的列属性，可以在调用的时候就指定复制哪些字段，而略过其它不需要复制的字段。
bool create指定是复制，还是新建？
2、用途：
（1）用于相同实体类之间的数据复制。
（2）用于不同实体类之间的数据复制。
（3）用于多个实体类合成为新的实体类。
3、示例：
下面是我们原来更新数据时的代码，是不是很麻烦？

var row = rows.FirstOrDefault();

if (row == null) continue;

row.StockCode = webItem.StockCode;

row.StockMarket = webItem.StockMarket;

row.StockName = webItem.StockName;

row.PriceClose = webItem.PriceClose;

row.RatioChange = webItem.RatioChange;

row.DateTimeUpdate = DateTime.Now;

row.FlagStatus = 0;

row.Para1_RatioAmp = webItem.Para1_RatioAmp;

row.Para1_RatioChange = webItem.Para1_RatioChange;

row.Para1_PriceHigh = webItem.Para1_PriceHigh;

row.Para1_PriceLast = webItem.Para1_PriceLast;

row.Para1_PriceLower = webItem.Para1_PriceLower;

row.Para1_PriceClose = webItem.Para1_PriceClose;

row.Para1_PriceOpen = webItem.Para1_PriceOpen;

row.Para1_TradeAmount = webItem.Para1_TradeAmount;

row.Para1_TradeVolume = webItem.Para1_TradeVolume;

row.Para1_RatioTurnOver = webItem.Para1_RatioTurnOver;

row.Para2_RatioAmp = webItem.Para2_RatioAmp;

row.Para2_RatioChange = webItem.Para2_RatioChange;

row.Para2_PriceHigh = webItem.Para2_PriceHigh;

row.Para2_PriceLast = webItem.Para2_PriceLast;

row.Para2_PriceLower = webItem.Para2_PriceLower;

row.Para2_PriceClose = webItem.Para2_PriceClose;

row.Para2_PriceOpen = webItem.Para2_PriceOpen;

row.Para2_TradeAmount = webItem.Para2_TradeAmount;

row.Para2_TradeVolume = webItem.Para2_TradeVolume;

row.Para2_RatioTurnOver = webItem.Para2_RatioTurnOver;

row.Para3_RatioAmp = webItem.Para3_RatioAmp;

row.Para3_RatioChange = webItem.Para3_RatioChange;

row.Para3_PriceHigh = webItem.Para3_PriceHigh;

row.Para3_PriceLast = webItem.Para3_PriceLast;

row.Para3_PriceLower = webItem.Para3_PriceLower;

row.Para3_PriceClose = webItem.Para3_PriceClose;

row.Para3_PriceOpen = webItem.Para3_PriceOpen;

row.Para3_TradeAmount = webItem.Para3_TradeAmount;

row.Para3_TradeVolume = webItem.Para3_TradeVolume;

row.Para3_RatioTurnOver = webItem.Para3_RatioTurnOver;

row.Para4_RatioAmp = webItem.Para4_RatioAmp;

row.Para4_RatioChange = webItem.Para4_RatioChange;

row.Para4_PriceHigh = webItem.Para4_PriceHigh;

row.Para4_PriceLast = webItem.Para4_PriceLast;

row.Para4_PriceLower = webItem.Para4_PriceLower;

row.Para4_PriceClose = webItem.Para4_PriceClose;

row.Para4_PriceOpen = webItem.Para4_PriceOpen;

row.Para4_TradeAmount = webItem.Para4_TradeAmount;

row.Para4_TradeVolume = webItem.Para4_TradeVolume;

row.Para4_RatioTurnOver = webItem.Para4_RatioTurnOver;

现在用一个通用的方法就避免了需要手工去写那些代码。

        private void UpdateMarket<TSource, TTarget>(TSource s, TTarget t, string[] reqItems = null, bool create = false)

            where TSource : new()

            where TTarget : new()

        {

            foreach (var p in t.GetType().GetProperties()) // 以目标表为参照对象

            {

                // 复制到本地变量

                var p1 = p;

                // PkId 字段略过，Insert时略过Update，Update时略过Create。

                if (p1.Name.CompareExt("PkId") || (create ? p1.Name.CompareExt("DateTimeUpdate") : p1.Name.CompareExt("DateTimeCreate"))) continue;

                if (reqItems != null && reqItems.All(w => w != p1.Name)) continue;

                var s1 = s.GetType().GetField(p1.Name); // 找到来源实体类的字段信息

                if (s1 != null)

                {

                    p1.SetValue(t, s1.GetValue(null), null);

                }

                else

                {

                    var s2 = s.GetType().GetProperty(p1.Name);

                    if (s2 == null) continue;

                    p1.SetValue(t, s2.GetValue(s, null), null);

                }

            }

        }

...全文

3515 17 打赏收藏转发到动态举报

写回复

用AI写文章

17 条回复

切换为时间正序

请发表友善的回复…

发表回复

baidu_35615276 2016-07-15

打赏
举报

貌似你那个遍历条件也找不到字段啊！

   var s1 = s.GetType().GetField(p1.Name); // 找到来源实体类的字段信息
                if (s1 != null)
                {
                    p1.SetValue(t, s1.GetValue(null), null);
                }

，请问这里的意义是??内存多了没地方用啊

baidu_35615276 2016-07-15