1、Lambda表达式可以应用于任何匿名方法可以应用的场合。
好处在于：简化编程，更节省编码时间。
2、Predicate<T> 类型，
（泛型委托）
（它用于包装）
任何 输入参数类型为T
且
返回值为bool值的方法。如：
Predicate<int> callback = new Predicate<int> (IsEvenNumber) ;
static bool IsEvenNumber(int i)
{
return(i % 2) == 0;
}
3、examples.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Drawing;
namespace LambdaSample
{
class Program
{
public static void Main()
{
LambdaSystax();
Console.ReadLine();
}
public static void LambdaSystax()
{
List<int> list = new List<int>();
list.AddRange(new int[] { 20,28,4,9,38 });
List<int> evenNumbers = list.FindAll((i) =>
{
Console.WriteLine("value of i is currently: {0}", i);
bool isEven = ((i % 2) == 0);
return isEven;
});
Console.WriteLine("Here are your even numbers:");
foreach (int evenNumber in evenNumbers)
{
Console.WriteLine("{0}\t", evenNumber);
}
}
}
}
/*
namespace LambdaSample
{
class Program
{
public static void Main()
{
List<string> dinosaurs = new List<string>();
dinosaurs.Add("Compsognathus");
dinosaurs.Add("Amargasaurus");
dinosaurs.Add("Oviraptor");
dinosaurs.Add("Velociraptor");
dinosaurs.Add("Deinonychus");
dinosaurs.Add("Dilophosaurus");
dinosaurs.Add("Gallimimus");
dinosaurs.Add("Triceratops");
Console.WriteLine();
foreach (string dinosaur in dinosaurs)
{
Console.WriteLine(dinosaur);
}
Console.WriteLine("\nTrueForAll(EndsWithSaurus): {0}",
dinosaurs.TrueForAll(EndsWithSaurus));
Console.WriteLine("\nFind(EndsWithSaurus): {0}",
dinosaurs.Find(EndsWithSaurus));
Console.WriteLine("\nFindLast(EndsWithSaurus): {0}",
dinosaurs.FindLast(EndsWithSaurus));
Console.WriteLine("\nFindAll(EndsWithSaurus):");
List<string> sublist = dinosaurs.FindAll(EndsWithSaurus);
foreach (string dinosaur in sublist)
{
Console.WriteLine(dinosaur);
}
Console.WriteLine(
"\n{0} elements removed by RemoveAll(EndsWithSaurus).",
dinosaurs.RemoveAll(EndsWithSaurus));
Console.WriteLine("\nList now contains:");
foreach (string dinosaur in dinosaurs)
{
Console.WriteLine(dinosaur);
}
Console.WriteLine("\nExists(EndsWithSaurus): {0}",
dinosaurs.Exists(EndsWithSaurus));
Console.ReadLine();
}
// Search predicate returns true if a string ends in "saurus".
private static bool EndsWithSaurus(String s)
{
if ((s.Length > 5) &&
(s.Substring(s.Length - 6).ToLower() == "saurus"))
{
return true;
}
else
{
return false;
}
}
}
}
*/
/*
namespace LambdaSample
{
class Program
{
public static void Main()
{
// Create an array of five Point structures.
Point[] points = { new Point(100, 200),
new Point(200, 300), new Point(300, 400),
new Point(275, 395), new Point(295, 450) };
// To find the first Point structure for which X times Y
// is greater than 100000, pass the array and a delegate
// that represents the ProductGT10 method to the Shared
// Find method of the Array class.
Point first = Array.Find(points, ProductGT10);
// Note that you do not need to create the delegate
// explicitly, or to specify the type parameter of the
// generic method, because the C# compiler has enough
// context to determine that information for you.
// Display the first structure found.
Console.WriteLine("Found: X = {0}, Y = {1}", first.X, first.Y);
Console.ReadLine();
}
// This method implements the test condition for the Find
// method.
private static bool ProductGT10(Point p)
{
if (p.X * p.Y > 100000)
{
return true;
}
else
{
return false;
}
}
//static void Main(string[] args)
//{
//}
}
}*/