将范围从一个列表添加到另一个列表

Question

我有一个list(of string)，我搜索它以获得一个开始和结束范围，然后我需要将这个范围添加到一个单独的列表中

例:列表A= "a“ab”abc“"ba”"bac“"bdb”"cba“"zba”

我需要名单B是所有的b (3-5)

我想做的是ListB.Addrange(ListA(3-5))

我怎样才能做到这一点？

Answer 1

使用List.GetRange()

Imports System
Imports System.Collections.Generic

Sub Main()
    '                                               0    1     2      3     4      5      6      7
    Dim ListA As New List(Of String)(New String() {"a", "ab", "abc", "ba", "bac", "bdb", "cba", "zba"})
    Dim ListB As New List(Of String)

    ListB.AddRange(ListA.GetRange(3, 3))
    For Each Str As String In ListB
        Console.WriteLine(Str)
    Next
    Console.ReadLine()
End Sub

或者您可以使用Linq

Imports System
Imports System.Collections.Generic
Imports System.Linq

Module Module1
    Sub Main()
        '                                               0    1     2      3     4      5      6      7
        Dim ListA As New List(Of String)(New String() {"a", "ab", "abc", "ba", "bac", "bdb", "cba", "zba"})
        Dim ListB As New List(Of String)

        ListB.AddRange(ListA.Where(Function(s) s.StartsWith("b")))
        ' This does the same thing as .Where()
        ' ListB.AddRange(ListA.FindAll(Function(s) s.StartsWith("b")))
        For Each Str As String In ListB
            Console.WriteLine(Str)
        Next
        Console.ReadLine()
    End Sub
End Module

结果：

​

​