表达式树Expression是Linq中一项比较重要的功能,对其深刻了解Lamda以及计算表达式有很大的帮助.
下面是利用 Expression<Func<Object>>[]取得Func<Object>中的操作数或成员名称以及值。
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Linq.Expressions;
using System.Reflection; namespace ExpressionTree
{
class Program
{
static void Main(string[] args)
{
MyClass cls = new MyClass() { Memo = "ffffddddd", Name = "dfdf", Age = };
Dictionary<string, string> dic = GetProps(() => cls.Memo, () => cls.Age); foreach (KeyValuePair<string,string> item in dic)
{
Console.WriteLine(item.Key + "=" + item.Value);
} Console.Read(); } static Dictionary<string, string> GetProps(params Expression<Func<Object>>[] funcs)
{
Dictionary<string, string> dic = new Dictionary<string, string>(); MemberExpression member = null;
UnaryExpression unary = null; foreach (Expression<Func<Object>> func in funcs)
{
unary = func.Body as UnaryExpression;
if (unary != null)
{
member = unary.Operand as MemberExpression;
}
else
{
member = func.Body as MemberExpression;
}
PropertyInfo prop = member.Member as PropertyInfo;
object value = func.Compile().Invoke(); dic.Add(prop.Name, Convert.ToString(value));
} return dic;
}
} class MyClass
{
public string Name { get; set; }
public int Age { get; set; }
public string Memo { get; set; }
}
}