02.泛型+反射，接收一个TIn类型的，返回一个TOut类型的反射，通过反射遍历赋值。
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace ThreeHomeWork.MappingExtend
{
public class ReflectionMapper
{
/// <summary>
/// 反射
/// </summary>
/// <typeparam name="TIn"></typeparam>
/// <typeparam name="TOut"></typeparam>
/// <param name="tIn"></param>
/// <returns></returns>
public static TOut Trans<TIn, TOut>(TIn tIn)
{
TOut tOut = Activator.CreateInstance<TOut>();//创建对象
foreach (var itemOut in tOut.GetType().GetProperties())//遍历属性
{
foreach (var itemIn in tIn.GetType().GetProperties())
{
if (itemOut.Name.Equals(itemIn.Name))
{
itemOut.SetValue(tOut, itemIn.GetValue(tIn));
break;
}
}
}
foreach (var itemOut in tOut.GetType().GetFields())//遍历字段
{
foreach (var itemIn in tIn.GetType().GetFields())
{
if (itemOut.Name.Equals(itemIn.Name))
{
itemOut.SetValue(tOut, itemIn.GetValue(tIn));
break;
}
}
}
return tOut;
}
}
}
03.使用第三方序列化反序列化工具，Newtonsoft.Json是比较好的一个工具，这种方式序列化代码虽然一行搞定，但是序列化和反序列化的动作比反射动作大点，耗时会比较高。
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace ExpressionDemo.MappingExtend
{
public class SerializeMapper
{
/// <summary>
/// 序列化反序列化方式
/// </summary>
/// <typeparam name="TIn"></typeparam>
/// <typeparam name="TOut"></typeparam>
public static TOut Trans<TIn, TOut>(TIn tIn)
{
return JsonConvert.DeserializeObject<TOut>(JsonConvert.SerializeObject(tIn));
}
}
}
04.生成表达式目录树，泛型缓存，使用泛型缓存性能是最高的。动态实现Student与StudentDto的转换。
using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Text;
using System.Threading.Tasks;
namespace ThreeHomeWork.MappingExtend
{
/// <summary>
/// 生成表达式目录树 泛型缓存
/// </summary>
/// <typeparam name="TIn"></typeparam>
/// <typeparam name="TOut"></typeparam>
public class ExpressionGenericMapper<TIn, TOut>//Mapper`2
{
private static Func<TIn, TOut> _FUNC = null;
static ExpressionGenericMapper()
{
ParameterExpression parameterExpression = Expression.Parameter(typeof(TIn), "p");
List<MemberBinding> memberBindingList = new List<MemberBinding>();
foreach (var item in typeof(TOut).GetProperties())
{
MemberExpression property = Expression.Property(parameterExpression, typeof(TIn).GetProperty(item.Name));
MemberBinding memberBinding = Expression.Bind(item, property);
memberBindingList.Add(memberBinding);
}
foreach (var item in typeof(TOut).GetFields())
{
MemberExpression property = Expression.Field(parameterExpression, typeof(TIn).GetField(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
});
_FUNC = lambda.Compile();//拼装是一次性的
}
public static TOut Trans(TIn t)
{
return _FUNC(t);
}
}
}
