最近在对list进行add新元素时,发现add使用的是引用,因此在增加重复元素时,得使用深拷贝进行元素的复制。类对象的复制,一个个属性进行赋值略显笨拙,因此在网上找到了个通用的方法。比较好用,据称为表达树式https://www.cnblogs.com/emrys5/p/expression_trans_model.html
public static class TransExpV2<TIn, TOut> { private static readonly Func<TIn, TOut> cache = GetFunc(); private static Func<TIn, TOut> GetFunc() { ParameterExpression parameterExpression = Expression.Parameter(typeof(TIn), "p"); List<MemberBinding> memberBindingList = new List<MemberBinding>(); foreach (var item in typeof(TOut).GetProperties()) { if (!item.CanWrite) continue; MemberExpression property = Expression.Property(parameterExpression, typeof(TIn).GetProperty(item.Name)); MemberBinding memberBinding = Expression.Bind(item, property); memberBindingList.Add(memberBinding); } MemberInitExpression memberInitExpression = Expression.MemberInit(Expression.New(typeof(TOut)), memberBindingList.ToArray()); Expression<Func<TIn, TOut>> lambda = Expression.Lambda<Func<TIn, TOut>>(memberInitExpression, new ParameterExpression[] { parameterExpression }); return lambda.Compile(); } public static TOut Trans(TIn tIn) { return cache(tIn); } }
调用:StudentSecond ss= TransExpV2<Student, StudentSecond>.Trans(s);