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ExpressionMapper（对象映射）

IT知识ExpressionExpress

【ExpressionMapper（对象映射）】青春须早为，岂能长少年。这篇文章主要讲述ExpressionMapper（对象映射）相关的知识，希望能为你提供帮助。
 
性能仅次于硬编码，推荐使用

public static class ExpressionMapper< TIn, TOut> { private static readonly ConcurrentDictionary< string, Func< TIn, TOut> > CACHE = new ConcurrentDictionary< string, Func< TIn, TOut> > (); public static TOut Trans(TIn tIn) { string cacheName = $"cache_{typeof(TIn).FullName}_{typeof(TOut).FullName}"; Func< TIn, TOut> func = CACHE.GetOrAdd(cacheName, key => { ParameterExpression parameterExpression = Expression.Parameter(typeof(TIn), "p"); List< MemberBinding> memberBindingList = new List< MemberBinding> (); PropertyInfo inProperty = null; foreach (var item in typeof(TOut).GetProperties()) { if (!item.CanWrite) continue; inProperty = typeof(TIn).GetProperty(item.Name); if (inProperty!=null) { MemberExpression property = Expression.Property(parameterExpression, inProperty); 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(); }); return func(tIn); }}

 

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