实体类型互转

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

// S:源类型    T:目标类型         static List<T> ByExpTree<S, T>(List<S> list)        {            var props = typeof(S).GetProperties().Where(p => typeof(T).GetProperty(p.Name) != null).Select(x => new { a = x, b = typeof(T).GetProperty(x.Name) });            var param = Expression.Parameter(typeof(S), "x");            List<Expression> exps = new List<Expression>();            var cre = Expression.New(typeof(T));            var newb = Expression.Variable(typeof(T));            var assb = Expression.Assign(newb, cre);            exps.Add(assb);            foreach (var item in props)            {                var getexp = Expression.MakeMemberAccess(param, item.a);                var setexp = Expression.MakeMemberAccess(newb, item.b);                var ass = Expression.Assign(setexp, getexp);                exps.Add(ass);            }            exps.Add(newb);            var body = Expression.Block(new ParameterExpression[] { newb }, exps);            var sel = Expression.Lambda<Func<S, T>>(body, param);            return list.Select(sel.Compile()).ToList();        }

　　PS：代码来源于网络，原本为固定类型互转，测试后发现此方式比反射及利用json快很多,修改调整为泛型方法，仅作记录。   有时我们仅有为数不多的类需要进行转换，不想使用第三方的map库，可使用此方法。