List<T>.RemoveRange(Int32, Int32) 方法
定义
重要
一些信息与预发行产品相关,相应产品在发行之前可能会进行重大修改。 对于此处提供的信息,Microsoft 不作任何明示或暗示的担保。
从 . 中删除一系列元素 List<T>。
public:
void RemoveRange(int index, int count);
public void RemoveRange(int index, int count);
member this.RemoveRange : int * int -> unit
Public Sub RemoveRange (index As Integer, count As Integer)
参数
- index
- Int32
要移除的元素范围的从零开始的索引。
- count
- Int32
要移除的元素数。
例外
index 并且 count 不表示中 List<T>有效元素的范围。
示例
下面的示例演示 RemoveRange 对范围执行操作的 List<T> 类的方法和其他各种方法。 创建和修改列表后, RemoveRange 该方法用于从索引位置 2 开始从列表中删除两个元素。
using System;
using System.Collections.Generic;
string[] input = { "Apple",
"Banana",
"Orange" };
List<string> fruits = new List<string>(input);
Console.WriteLine("\nCapacity: {0}", fruits.Capacity);
Console.WriteLine();
foreach (string fruit in fruits)
{
Console.WriteLine(fruit);
}
Console.WriteLine("\nAddRange(fruits)");
fruits.AddRange(fruits);
Console.WriteLine();
foreach (string fruit in fruits)
{
Console.WriteLine(fruit);
}
Console.WriteLine("\nRemoveRange(2, 2)");
fruits.RemoveRange(2, 2);
Console.WriteLine();
foreach (string fruit in fruits)
{
Console.WriteLine(fruit);
}
input = new string[] { "Mango",
"Pineapple",
"Watermelon" };
Console.WriteLine("\nInsertRange(3, input)");
fruits.InsertRange(3, input);
Console.WriteLine();
foreach (string fruit in fruits)
{
Console.WriteLine(fruit);
}
Console.WriteLine("\noutput = fruits.GetRange(2, 3).ToArray()");
string[] output = fruits.GetRange(2, 3).ToArray();
Console.WriteLine();
foreach (string fruit in output)
{
Console.WriteLine(fruit);
}
/*
This code example produces the following output:
Capacity: 3
Apple
Banana
Orange
AddRange(fruits)
Apple
Banana
Orange
Apple
Banana
Orange
RemoveRange(2, 2)
Apple
Banana
Banana
Orange
InsertRange(3, input)
Apple
Banana
Banana
Mango
Pineapple
Watermelon
Orange
output = fruits.GetRange(2, 3).ToArray()
Banana
Mango
Pineapple
*/
Imports System.Collections.Generic
Partial Public Class Program
Public Shared Sub ShowFruits()
Dim input() As String = { "Apple", _
"Banana", _
"Orange" }
Dim fruits As New List(Of String)(input)
Console.WriteLine(vbLf & "Capacity: {0}", fruits.Capacity)
Console.WriteLine()
For Each fruit As String In fruits
Console.WriteLine(fruit)
Next
Console.WriteLine(vbLf & "AddRange(fruits)")
fruits.AddRange(fruits)
Console.WriteLine()
For Each fruit As String In fruits
Console.WriteLine(fruit)
Next
Console.WriteLine(vbLf & "RemoveRange(2, 2)")
fruits.RemoveRange(2, 2)
Console.WriteLine()
For Each fruit As String In fruits
Console.WriteLine(fruit)
Next
input = New String() { "Mango", _
"Pineapple", _
"Watermelon" }
Console.WriteLine(vbLf & "InsertRange(3, input)")
fruits.InsertRange(3, input)
Console.WriteLine()
For Each fruit As String In fruits
Console.WriteLine(fruit)
Next
Console.WriteLine(vbLf & "output = fruits.GetRange(2, 3).ToArray")
Dim output() As String = fruits.GetRange(2, 3).ToArray()
Console.WriteLine()
For Each fruit As String In output
Console.WriteLine(fruit)
Next
End Sub
End Class
' This code example produces the following output:
'
' Capacity: 3
'
' Apple
' Banana
' Orange
'
' AddRange(fruits)
'
' Apple
' Banana
' Orange
' Apple
' Banana
' Orange
'
' RemoveRange(2, 2)
'
' Apple
' Banana
' Banana
' Orange
'
' InsertRange(3, input)
'
' Apple
' Banana
' Banana
' Mango
' Pineapple
' Watermelon
' Orange
'
' output = fruits.GetRange(2, 3).ToArray
'
' Banana
' Mango
' Pineapple
注解
将删除这些项,并且其后面的所有元素都有List<T>其索引减少。count
此方法是 O(n) 操作,其中 n 为 Count。