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  1. using System;
  2. using System.Linq;
  3. using System.Linq.Expressions;
  4.  
  5. public class Program
  6. {
  7. 	public static void Main()
  8. 	{
  9. 		var someClass = new SomeClass
  10. 		{
  11. 			PropertyOne = "Value1",
  12. 			PropertyTwo = "Value2",
  13. 			PropertyThree = "Value3",
  14. 			PropertyFour = 4,
  15. 		};
  16. 		var props = new string[] { "PropertyOne", "PropertyTwo", "PropertyFour"};
  17. 		var keyFactoryExp = CreateExpression<SomeClass>(props);
  18. 		var keyFactory = keyFactoryExp.Compile();
  19. 		Console.WriteLine(keyFactory(someClass));
  20. 	}
  21.  
  22.  
  23. 	static Expression<Func<T, string>> CreateExpression<T>(string[] props)
  24. 	{
  25. 		var par = Expression.Parameter(typeof(T));
  26. 		return Expression.Lambda<Func<T, string>>(Expression.Call(typeof(string), "Join", Type.EmptyTypes, Expression.Constant("|"),
  27. 			Expression.NewArrayInit(typeof(object), props.Select(prop => Expression.Convert(Expression.Property(par, prop), typeof(object))).ToArray())), par);
  28. 	}
  29.  
  30. 	class SomeClass
  31. 	{
  32. 		public string PropertyOne { get; set; }
  33. 		public string PropertyTwo { get; set; }
  34. 		public string PropertyThree { get; set; }
  35. 		public int PropertyFour { get; set; }
  36. 	}
  37. }
Success #stdin #stdout 0.11s 30388KB
comments (?)
stdin 
Standard input is empty
stdout 
Value1|Value2|4
https://ideone.com/VR1940
language:
C# (gmcs 5.20.1)
created:
3 years ago
visibility:
secret

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