利用表示式目錄樹進行實體對映
阿新 • • 發佈:2020-07-28
using System; using System.Collections.Generic; using System.Linq.Expressions; namespace HC.Common.Tools.DataConvert { /// <summary> /// 利用表示式目錄樹進行實體對映 /// </summary> /// <typeparam name="TSource"></typeparam> /// <typeparam name="TTarget"></typeparam> public static class ExpressionMapper<TSource, TTarget> where TSource : class, new() where TTarget : class, new() { private static Func<TSource, TTarget> _func = null; static ExpressionMapper() { try { ParameterExpression parameterExpression = Expression.Parameter(typeof(TSource), "s"); List<MemberBinding> memberBindings = new List<MemberBinding>(); foreach (var item in typeof(TTarget).GetProperties()) { var sProp = typeof(TSource).GetProperty(item.Name); if (sProp != null && sProp.PropertyType == item.PropertyType && sProp.CanWrite && item.CanWrite) { MemberExpression property = Expression.Property(parameterExpression, sProp); MemberBinding memberBinding = Expression.Bind(item, property); memberBindings.Add(memberBinding); } } foreach (var item in typeof(TTarget).GetFields()) { var sField = typeof(TSource).GetField(item.Name); if (sField != null && sField.FieldType == item.FieldType) { MemberExpression property = Expression.Field(parameterExpression, sField); MemberBinding memberBinding = Expression.Bind(item, property); memberBindings.Add(memberBinding); } } MemberInitExpression memberInitExpression = Expression.MemberInit(Expression.New(typeof(TTarget)), memberBindings); Expression<Func<TSource, TTarget>> lamada = Expression.Lambda<Func<TSource, TTarget>>(memberInitExpression, new ParameterExpression[] { parameterExpression }); _func = lamada.Compile(); } catch (Exception ex) { LoggerHelper.Log4netHelper.Error($"{typeof(TSource).Name} 轉 {typeof(TTarget).Name} 出錯:{ex.Message}"); } } public static TTarget Map(TSource source) { return _func.Invoke(source); } public static List<TTarget> Map(List<TSource> source) { var ret = new List<TTarget>(); foreach (var item in source) { ret.Add(_func.Invoke(item)); } return ret; } } }