LinkedList < T >类存在于System.Collections.Generic命名空间中。这种通用类型允许快速插入和删除元素。它实现了经典的链表。每个对象都是单独分配的。在LinkedList中，某些操作不需要复制整个集合。但是在许多常见情况下，LinkedList会影响性能。
LinkedList类的特征：
- LinkedList < T >是通用链表。它支持枚举器。
- 插入和删除是O(1)操作。
- 您可以删除节点，然后将它们重新插入到同一列表或另一个列表中，这样就不会在堆上分配任何其他对象。
- 由于列表还维护内部计数，因此获取Count属性是O(1)操作。
- LinkedList < T >对象中的每个节点的类型为LinkedListNode < T >。
- LinkedList类不支持链接，拆分，循环或其他可能使列表处于不一致状态的功能。
- 如果LinkedList为空，则First和Last属性包含null。
- LinkedList是双重链接的，因此，每个节点都指向下一个节点，并指向上一个节点。
建设者
| Constructor | Description |
|---|---|
| LinkedList() | Initializes a new instance of the LinkedList class that is empty. |
| LinkedList(IEnumerable) | Initializes a new instance of the LinkedList class that contains elements copied from the specified IEnumerable and has sufficient capacity to accommodate the number of elements copied. |
| LinkedList(SerializationInfo, StreamingContext) | Initializes a new instance of the LinkedList class that is serializable with the specified SerializationInfo and StreamingContext. |
例子：
// C# code to create a LinkedList
using System;
using System.Collections;
using System.Collections.Generic;
class GFG {
// Driver code
public static void Main()
{
// Creating a LinkedList of Strings
LinkedList myList = new LinkedList();
// Adding nodes in LinkedList
myList.AddLast("Geeks");
myList.AddLast("for");
myList.AddLast("Data Structures");
myList.AddLast("Noida");
// To check if LinkedList is empty or not
if (myList.Count > 0)
Console.WriteLine("LinkedList is not empty");
else
Console.WriteLine("LinkedList is empty");
}
}
输出：
LinkedList is not empty
特性
| Property | Description |
|---|---|
| Count | Gets the number of nodes actually contained in the LinkedList. |
| First | Gets the first node of the LinkedList. |
| Last | Gets the last node of the LinkedList. |
例子：
// C# code to illustrate the
// LinkedList class properties
using System;
using System.Collections;
using System.Collections.Generic;
class GFG {
// Driver code
public static void Main()
{
// Creating a LinkedList of Strings
LinkedList myList = new LinkedList();
// Adding nodes in LinkedList
myList.AddLast("GeeksforGeeks");
myList.AddLast("GFG");
myList.AddLast("Data Structures");
myList.AddLast("Noida");
// ------- Count Property -------
// To get the first node of the LinkedList
if (myList.Count > 0)
Console.WriteLine(myList.First.Value);
else
Console.WriteLine("LinkedList is empty");
// ------- Last Property -------
// To get the last node of the LinkedList
if (myList.Count > 0)
Console.WriteLine(myList.Last.Value);
else
Console.WriteLine("LinkedList is empty");
}
}
输出：
GeeksforGeeks
Noida
方法
| Method | Description |
|---|---|
| AddAfter | Adds a new node or value after an existing node in the LinkedList. |
| AddBefore | Adds a new node or value before an existing node in the LinkedList. |
| AddFirst | Adds a new node or value at the start of the LinkedList. |
| AddLast | Adds a new node or value at the end of the LinkedList. |
| Clear() | Removes all nodes from the LinkedList. |
| Contains(T) | Determines whether a value is in the LinkedList. |
| CopyTo(T[], Int32) | Copies the entire LinkedList to a compatible one-dimensional Array, starting at the specified index of the target array. |
| Equals(Object) | Determines whether the specified object is equal to the current object. |
| Find(T) | Finds the first node that contains the specified value. |
| FindLast(T) | Finds the last node that contains the specified value. |
| GetEnumerator() | Returns an enumerator that iterates through the LinkedList. |
| GetHashCode() | Serves as the default hash function. |
| GetObjectData(SerializationInfo, StreamingContext) | Implements the ISerializable interface and returns the data needed to serialize the LinkedList instance. |
| GetType() | Gets the Type of the current instance. |
| MemberwiseClone() | Creates a shallow copy of the current Object. |
| OnDeserialization(Object) | Implements the ISerializable interface and raises the deserialization event when the deserialization is complete. |
| Remove(LinkedListNode) | Removes the specified node from the LinkedList. |
| Remove(T) | Removes the first occurrence of the specified value from the LinkedList. |
| RemoveFirst() | Removes the node at the start of the LinkedList. |
| RemoveLast() | Removes the node at the end of the LinkedList. |
| ToString() | Returns a string that represents the current object. |
例子：
// C# code to check if a
// value is in LinkedList
using System;
using System.Collections;
using System.Collections.Generic;
class GFG {
// Driver code
public static void Main()
{
// Creating a LinkedList of Strings
LinkedList myList = new LinkedList();
// Adding nodes in LinkedList
myList.AddLast("A");
myList.AddLast("B");
myList.AddLast("C");
myList.AddLast("D");
myList.AddLast("E");
// To check if a value is in LinkedList
Console.WriteLine(myList.Contains("B"));
}
}
输出：
True
例子：
// C# code to remove the specified
// node from the LinkedList
using System;
using System.Collections;
using System.Collections.Generic;
class GFG {
// Driver code
public static void Main()
{
// Creating a LinkedList of Integers
LinkedList myList = new LinkedList();
// Adding nodes in LinkedList
myList.AddLast(2);
myList.AddLast(4);
myList.AddLast(6);
myList.AddLast(8);
// To get the count of nodes in LinkedList
// before removing all the nodes
Console.WriteLine("Total nodes in myList are : " + myList.Count);
// Displaying the nodes in LinkedList
foreach(int i in myList)
{
Console.WriteLine(i);
}
// Removing the first node from the LinkedList
myList.Remove(myList.First);
// To get the count of nodes in LinkedList
// after removing all the nodes
Console.WriteLine("Total nodes in myList are : " + myList.Count);
// Displaying the nodes in LinkedList
foreach(int i in myList)
{
Console.WriteLine(i);
}
}
}
输出：
Total nodes in myList are : 4
2
4
6
8
Total nodes in myList are : 3
4
6
8
参考：
- https://docs.microsoft.com/zh-cn/dotnet/api/system.collections.generic.linkedlist-1?view=netframework-4.7.2