操作說明：使用群組將檔案分割成許多檔案 (LINQ) (Visual Basic)
此範例示範如何合併兩個檔案的內容，然後建立一組以新方法組織資料的新檔案。
建立資料檔
將下列名稱複製到名為 names1.txt 的文字檔，並將它儲至專案資料夾：
Bankov, Peter Holm, Michael Garcia, Hugo Potra, Cristina Noriega, Fabricio Aw, Kam Foo Beebe, Ann Toyoshima, Tim Guy, Wey Yuan Garcia, Debra將下列名稱複製到名為 names2.txt 的文字檔，並將它儲至專案資料夾：請注意，這兩個檔案中有些名稱是相同的。
Liu, Jinghao Bankov, Peter Holm, Michael Garcia, Hugo Beebe, Ann Gilchrist, Beth Myrcha, Jacek Giakoumakis, Leo McLin, Nkenge El Yassir, Mehdi
範例
Class SplitWithGroups
Shared Sub Main()
Dim fileA As String() = System.IO.File.ReadAllLines("../../../names1.txt")
Dim fileB As String() = System.IO.File.ReadAllLines("../../../names2.txt")
' Concatenate and remove duplicate names based on
Dim mergeQuery As IEnumerable(Of String) = fileA.Union(fileB)
' Group the names by the first letter in the last name
Dim groupQuery = From name In mergeQuery
Let n = name.Split(New Char() {","})
Order By n(0)
Group By groupKey = n(0)(0)
Into groupName = Group
' Create a new file for each group that was created
' Note that nested foreach loops are required to access
' individual items with each group.
For Each gGroup In groupQuery
Dim fileName As String = "..'..'..'testFile_" & gGroup.groupKey & ".txt"
Dim sw As New System.IO.StreamWriter(fileName)
Console.WriteLine(gGroup.groupKey)
For Each item In gGroup.groupName
Console.WriteLine(" " & item.name)
sw.WriteLine(item.name)
Next
sw.Close()
Next
' Keep console window open in debug mode.
Console.WriteLine("Files have been written. Press any key to exit.")
Console.ReadKey()
End Sub
End Class
' Console Output:
' A
' Aw, Kam Foo
' B
' Bankov, Peter
' Beebe, Ann
' E
' El Yassir, Mehdi
' G
' Garcia, Hugo
' Garcia, Debra
' Giakoumakis, Leo
' Gilchrist, Beth
' Guy, Wey Yuan
' H
' Holm, Michael
' L
' Liu, Jinghao
' M
' McLin, Nkenge
' Myrcha, Jacek
' N
' Noriega, Fabricio
' P
' Potra, Cristina
' T
' Toyoshima, Tim
此程式會在與資料檔相同的資料夾中，寫入每個群組的個別檔案。
編譯程式碼
建立 Visual Basic 主控台應用程式專案，並在 System.Linq 命名空間使用 Imports 陳述式。
