Generic--1 of C # Advanced programming Create generic classes

. NET has been supporting generics since version 2.0.

• Non-generic linked list

Gossip Hugh, now look at the non-generic simplified list class, which can contain any type of object.

In LinkedListNode.cs:

In a linked list, an element references another element, so you must create a class that encapsulates it in a linked list and references the next object.

1      Public classLinkedListNode2     {3          PublicLinkedListNode (Objectvalue)4         {5              This. Value =value;6         }7 8          Public ObjectValue {Get;Private Set; }9 Ten          PublicLinkedListNode Next {Get;Internal Set; } One          PublicLinkedListNode Prev {Get;Internal Set; } A}

In LinkedListNode.cs:

The LinkedList class contains the first of the LinkedListNode type, with the last attribute, which respectively marks the tail and the ends of the linked list. By implementing the GetEnumerator () method, you can traverse a linked list with a foreach statement.

1      Public classlinkedlist:ienumerable2     {3          PublicLinkedListNode First {Get;Private Set; }4          PublicLinkedListNode last {Get;Private Set; }5 6          PublicLinkedListNode AddLast (Objectnode)7         {8             varNewNode =NewLinkedListNode (node);9             if(First = =NULL)Ten             { OneFirst =NewNode; ALast =First ; -             } -             Else the             { -Last.next =NewNode; -Last =NewNode; -             } +             returnNewNode; -         } +  A          PublicIEnumerator GetEnumerator () at         { -LinkedListNode current =First ; -              while(Current! =NULL) -             { -                 yield returnCurrent . Value; -Current =Current . Next; in             } -}

In Program.cs:

1             varList1 =NewLinkedList ();2List1. AddLast (2);3List1. AddLast (4);4List1. AddLast ("6");5 6             foreach(intIinchList1)7             {8 Console.WriteLine (i);9}

At this point, a run exception occurs because an exception occurs when the 3rd element in the list is converted to an integer.

• generic linked list

To avoid this situation, create a generic list below.

In LinkedListNode.cs:

The LinkedListNode class is declared with a generic type T. The type of property value is the, not an object.

     Public classLinkedlistnode<t>   {       PublicLinkedListNode (T value) { This. Value =value; }          PublicT Value {Get;Private Set; }  PublicLinkedlistnode<t> Next {Get;Internal Set; }  PublicLinkedlistnode<t> Prev {Get;Internal Set; } }

In LinkedList.cs:

The LinkedList is also defined as a generic class.

1      Public classLinkedlist<t>: ienumerable<t>2     {3          PublicLinkedlistnode<t> First {Get;Private Set; }4          PublicLinkedlistnode<t> last {Get;Private Set; }5 6          PublicLinkedlistnode<t>AddLast (T node)7         {8             varNewNode =NewLinkedlistnode<t>(node);9             if(First = =NULL)Ten             { OneFirst =NewNode; ALast =First ; -             } -             Else the             { -Last.next =NewNode; -Last =NewNode; -             } +             returnNewNode; -         } +  A          PublicIenumerator<t>GetEnumerator () at         { -Linkedlistnode<t> current =First ; -  -              while(Current! =NULL) -             { -                 yield returnCurrent . Value; inCurrent =Current . Next; -             } to         } +  - IEnumerator ienumerable.getenumerator () the         { *             returnGetEnumerator (); $         }Panax Notoginseng}

In Program.cs:

1     class Program2     {3         Static voidMain ()4         {5             varList2 =Newlinkedlist<int>();6List2. AddLast (1);7List2. AddLast (3);8List2. AddLast (5);9 Ten             foreach(intIinchlist2) One             { A Console.WriteLine (i); -             } -  the             varList3 =Newlinkedlist<string>(); -List3. AddLast ("2"); -List3. AddLast (" Four"); -List3. AddLast (NULL); +  -             foreach(stringSinchlist3) +             { A Console.WriteLine (s); at             } - Console.read (); -  -}

foreach is now type-safe.

Generic--1 of C # Advanced programming Create generic classes