此範例示範如何合併包含文字行的檔案，然後排序結果。 具體而言，它會示範如何在兩組文字行上進行簡單的串接、聯集和交集。
設定專案和文字檔
將這些名稱複製到名為 names1.txt 的文字檔，並將它儲存在項目資料夾中：
Bankov, Peter Holm, Michael Garcia, Hugo Potra, Cristina Noriega, Fabricio Aw, Kam Foo Beebe, Ann Toyoshima, Tim Guy, Wey Yuan Garcia, Debra將這些名稱複製到名為 names2.txt 的文字檔，並將它儲存在專案資料夾中。 請注意，這兩個檔案有一些共同的名稱。
Liu, Jinghao Bankov, Peter Holm, Michael Garcia, Hugo Beebe, Ann Gilchrist, Beth Myrcha, Jacek Giakoumakis, Leo McLin, Nkenge El Yassir, Mehdi
範例
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
編譯程式碼
建立 Visual Basic 控制台應用程式專案。 將一個Imports語句添加到 System.Linq 命名空間。
