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C# 表达式目录树的应用详解

使用表达式目录树实现两个不同类型的属性赋值:

?

public class People

{

public int Age { get; set; }

public string Name { get; set; }

public int Id;

}

public class PeopleCopy

{

public int Age { get; set; }

public string Name { get; set; }

public int Id;

}

public class Class1

{

private static Dictionary< string , object> _Dic = new Dictionary< string , object>();

private static TOut TransExp< TIn , TOut>(TIn tIn) {

string key = $"funckey_{typeof(TIn).FullName}_{typeof(TOut).FullName}";

if (!_Dic.Keys.Contains(key)) {

ParameterExpression parameterExpression = Expression.Parameter(typeof(TIn), "p");

List< MemberBinding > memberBindingList = new List< MemberBinding >();

foreach (var item in typeof(TOut).GetProperties())

{

PropertyInfo propertyInfo = typeof(TIn).GetProperty(item.Name);

if (propertyInfo == null) { continue; }

MemberExpression property = Expression.Property(parameterExpression, propertyInfo);

memberBindingList.Add(Expression.Bind(item, property));

}

foreach (var item in typeof(TOut).GetFields())

{

FieldInfo fieldInfo = typeof(TIn).GetField(item.Name);

if (fieldInfo == null) { continue; }

MemberExpression property = Expression.Field(parameterExpression, fieldInfo);

memberBindingList.Add(Expression.Bind(item, property));

}

Expression< Func <TIn, TOut>> expression = Expression.Lambda< Func <TIn, TOut>>(Expression.MemberInit(Expression.New(typeof(TOut)), memberBindingList), new ParameterExpression[]

{

parameterExpression

});

Func< TIn , TOut> func = expression.Compile();

_Dic.Add(key,func);

}

return ((Func < TIn , TOut > )_Dic[key])(tIn);

}

}

static void Main(string[] args)

{

List< ClassLibrary1.PeopleCopy > PeoleCopyList = new List< ClassLibrary1.PeopleCopy >();

for (int i = 0; i < 5 ; i++)

{

ClassLibrary1.People people = new ClassLibrary1.People() { Id = 5 +1, Age = 25 , Name = "aaa" +i };

PeoleCopyList.Add(Class1.ToutGet<ClassLibrary1.People, ClassLibrary1.PeopleCopy>(people));

}

}

以上这篇C# 表达式目录树的应用详解就是小编分享给大家的全部内容了,希望能给大家一个参考,也希望大家多多支持服务器之家。

原文链接:http://www.cnblogs.com/Torey/archive/2017/12/16/8048131.html

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