Common Function Delegate types

1. Action (T ))
   Encapsulate a method that uses only one parameter and does not return a value.
   Structure: void method name (T obj) {// process };
   Example: using System;
   Using System. Collections. Generic;
   Class Program
   {
   Public string Name {get; set ;}
   Public void Print (Action <string> action)
   {
   Action (this. Name );
   }
   Static void Main (string [] args)
   {
   Console. WriteLine ("used in List <T> ");
   List <string> list = new List <string> {"Flash", "Past", "Lian", "Xi "};
   List. ForEach (Program. Print );
   Console. WriteLine ("custom method usage ");
   Program pro = new Program {Name = "FlashPast "};
   Pro. Print (Program. Print );
   Console. ReadLine ();
   }
   Public static void Print (string obj)
   {
   Console. WriteLine (obj );
   }
   }

2. Decision function delegate (Predicate (T ))
   Defines a set of conditions and determines whether the specified object meets these conditions.
   Structure: bool Match <T> (T obj) {// processing} using System;
   Using System. Collections. Generic;
   Class Program
   {
   Public string Name {get; set ;}
   Static void Main (string [] args)
   {
   Console. WriteLine ("used in List <T> ");
   Program pro = new Program {Name = "Flash "};
   List <string> list = new List <string> {"Flash", "Past", "Lian", "Xi "};
   String result = list. Find (pro. Match );
   Console. WriteLine (result );
   Console. ReadLine ();
   }
   Public bool Match (string obj)
   {
   Bool result = false;
   If (obj = this. Name)
   {
   Result = true;
   }
   Return result;
   }
   }

3. Converter (TInput, TOutput ))
   Indicates a method to convert an object from one type to another.
   Structure: TOutput Converter <TInput, TOutput> (TInput input) {// processing} using System;
   Using System. Collections. Generic;
   Class Program
   {
   Static void Main (string [] args)
   {
   Console. WriteLine ("used in List <T> ");
   List <string> stringList = new List <string> {"1", "2", "3", "4 "};
   List <int> intList = stringList. ConvertAll <int> (Program. Converter );
   IntList. ForEach (delegate (int obj) {Console. WriteLine (obj. ToString ());});
   Console. ReadLine ();
   }
   Public static int Converter (string input)
   {
   Int result;
   If (! Int. TryParse (input, out result ))
   {
   Result =-1;
   }
   Return result;
   }
   }

4. Comparison function delegate (Comparison (T ))
   Compares two objects of the same type.
   Structure: int Comparison <T> (T x, T y) {// processing} using System;
   Using System. Collections. Generic;
   Class Program
   {
   Static void Main (string [] args)
   {
   Console. WriteLine ("used in List <T> ");
   List <int> list = new List <int> {12, 5, 46, 37, 28, 8 };
   List. ForEach (delegate (int obj) {Console. WriteLine (obj );});
   List. Sort (Program. Comparison );
   List. ForEach (delegate (int obj) {Console. WriteLine (obj );});
   Console. ReadLine ();
   }
   Public static int Comparison (int x, int y)
   {
   Return x. CompareTo (y );
   }
   }