此示例演示如何合并包含文本行的文件，然后对结果进行排序。 具体而言，此示例演示如何对两组文本行执行简单的串联、联合和交集。
设置项目和文本文件
将这些名称复制到名为 names1.txt 的文本文件中，并将其保存在项目文件夹中：
Bankov, Peter Holm, Michael Garcia, Hugo Potra, Cristina Noriega, Fabricio Aw, Kam Foo Beebe, Ann Toyoshima, Tim Guy, Wey Yuan Garcia, Debra将这些名称复制到名为 names2.txt 的文本文件中，并将其保存在项目文件夹中。 请注意，这两个文件具有一些共同的名称。
Liu, Jinghao Bankov, Peter Holm, Michael Garcia, Hugo Beebe, Ann Gilchrist, Beth Myrcha, Jacek Giakoumakis, Leo McLin, Nkenge El Yassir, Mehdi
示例：
Class ConcatenateStrings
Shared Sub Main()
' Create the IEnumerable data sources.
Dim fileA As String() = System.IO.File.ReadAllLines("../../../names1.txt")
Dim fileB As String() = System.IO.File.ReadAllLines("../../../names2.txt")
' Simple concatenation and sort.
Dim concatQuery = fileA.Concat(fileB).OrderBy(Function(name) name)
' Pass the query variable to another function for execution
OutputQueryResults(concatQuery, "Simple concatenation and sort. Duplicates are preserved:")
' New query. Concatenate files and remove duplicates
Dim uniqueNamesQuery = fileA.Union(fileB).OrderBy(Function(name) name)
OutputQueryResults(uniqueNamesQuery, "Union removes duplicate names:")
' New query. Find the names that occur in both files.
Dim commonNamesQuery = fileA.Intersect(fileB)
OutputQueryResults(commonNamesQuery, "Merge based on intersect: ")
' New query in three steps for better readability
' First filter each list separately
Dim nameToSearch As String = "Garcia"
Dim mergeQueryA As IEnumerable(Of String) = From name In fileA
Let n = name.Split(New Char() {","})
Where n(0) = nameToSearch
Select name
Dim mergeQueryB = From name In fileB
Let n = name.Split(New Char() {","})
Where n(0) = nameToSearch
Select name
' Create a new query to concatenate and sort results. Duplicates are removed in Union.
' Note that none of the queries actually executed until the call to OutputQueryResults.
Dim mergeSortQuery = mergeQueryA.Union(mergeQueryB).OrderBy(Function(str) str)
' Now execute mergeSortQuery
OutputQueryResults(mergeSortQuery, "Concat based on partial name match """ & nameToSearch & """ from each list:")
' Keep console window open in debug mode.
Console.WriteLine("Press any key to exit.")
Console.ReadKey()
End Sub
Shared Sub OutputQueryResults(ByVal query As IEnumerable(Of String), ByVal message As String)
Console.WriteLine(System.Environment.NewLine & message)
For Each item As String In query
Console.WriteLine(item)
Next
Console.WriteLine(query.Count & " total names in list")
End Sub
End Class
' Output:
' Simple concatenation and sort. Duplicates are preserved:
' Aw, Kam Foo
' Bankov, Peter
' Bankov, Peter
' Beebe, Ann
' Beebe, Ann
' El Yassir, Mehdi
' Garcia, Debra
' Garcia, Hugo
' Garcia, Hugo
' Giakoumakis, Leo
' Gilchrist, Beth
' Guy, Wey Yuan
' Holm, Michael
' Holm, Michael
' Liu, Jinghao
' McLin, Nkenge
' Myrcha, Jacek
' Noriega, Fabricio
' Potra, Cristina
' Toyoshima, Tim
' 20 total names in list
' Union removes duplicate names:
' Aw, Kam Foo
' Bankov, Peter
' Beebe, Ann
' El Yassir, Mehdi
' Garcia, Debra
' Garcia, Hugo
' Giakoumakis, Leo
' Gilchrist, Beth
' Guy, Wey Yuan
' Holm, Michael
' Liu, Jinghao
' McLin, Nkenge
' Myrcha, Jacek
' Noriega, Fabricio
' Potra, Cristina
' Toyoshima, Tim
' 16 total names in list
' Merge based on intersect:
' Bankov, Peter
' Holm, Michael
' Garcia, Hugo
' Beebe, Ann
' 4 total names in list
' Concat based on partial name match "Garcia" from each list:
' Garcia, Debra
' Garcia, Hugo
' 2 total names in list
编译代码
创建 Visual Basic 控制台应用程序项目。 添加一条Imports语句到 System.Linq 命名空间。
