C # Learning Diary---Generic class, generic method, generic delegate

Generics allow you to defer writing a specification of the data type of a programming element in a class or method until you actually use it in your program. In other words, when declaring a class or method, because you do not know what type of argument the user is going to pass in, "Dig a Hole (" <T> ") in the place of the incoming type, and use it when we fill it with the specific data type.

Generic class:

We define a class based on the previous knowledge:

　

Class Data          {public              int  n_data;           }

At this point the data type of n_data has been determined to be of type int, so assigning a value to him can only be of type int, if overridden to the following generic class:

　　

Class data<t>             {public               T n_data;             }

At this point the data type of n_data is not sure what type, so for him to assign the value of the need to specify T is the type of n_data, that is, pits,

　

data<int> data = new data<int> ();    Specify T as int data<string> Data = new data<string> ();  Specify T As String

Of course, the above example is not able to specify the T array, if you want to let the N_data type array, the following example can be satisfied:

Using System;  Using System.Collections.Generic;  Using System.Linq;  Using System.Text;    Namespace Example  {      class data<t>//generic class      {public          t[] n_data;//generic variable public         Data (int size)// constructor method, new when calling the construction method to open space          {             n_data = new t[size];            }          Enter public         void SetData (int index,t value)         {             N_data[index] = value;         }          Output public         T GetData (int x)         {             return n_data[x];         }      }      Class program      {          static void Main (string[] args)          {              data<int> Data = new data<int> (5); C28/>DATA.N_DATA[2] = 2;             Console.WriteLine (Data.n_data[2]);}}  

The result is: 2

Generic methods:

Let's take the swap exchange as an example, in C + + the Swap function is written in this way:

#include <iostream>    using namespace std;  Template <typename t>  void Swap1 (T &a,t &b)//can also be considered generic  {    T temp;    temp = A;    A = b;    b = temp;  }  int main ()  {      int a=0,b=1;      Swap1 (A, b);      cout<<a<< "\ t" <<b<<endl;   return 0;  }

Results: 1 0
If A and B are character types, the above functions also apply. The C#swap method is as follows:

Using System;  Using System.Collections.Generic;  Using System.Linq;  Using System.Text;    Namespace Example  {      class data      {//swap method, ref is pass by address public          static void swap<t> (Ref t A, ref T B) 
  {              T temp;              temp = A;              A = b;              b = temp;          }          static void Main (string[] args)          {              string a = "HC";              String b = "666";              Swap (ref a,ref B);              Console.WriteLine (A + "\ T" +b); Result 666    HC          }      }  }

Result: 666 HC This is very similar to C + +.

Generic delegate:

The delegate also has generics, followed by the example above:

Using System;  Using System.Collections.Generic;  Using System.Linq;    Using System.Text; Namespace Example {public delegate void mydelegate<t> ();//Generic delegate class Data<t> {Priva          Te T A;          Private T B;              public void SetValue (T x, t y) {a = x;          b = y;              }//swap method, ref is passing public void swap () {T temp by address;              temp = A;              A = b;          b = temp;            } public void Printvalue () {Console.WriteLine (a + "\ T" + B); }} class Program {static void Main (string[] args) {data<string& Gt              data = new data<string> ();              Data.setvalue ("HC", "666");              mydelegate<string> my = new mydelegate<string> (DATA.SWAP);              my + = Data.printvalue;  My ();                Result 666 HC}   }             } 

Results:

About generics on the introduction so much, and what wrong place to welcome point ^_^

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