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Anvisningar: Fråga efter filer med ett angivet attribut eller namn (Visual Basic)

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Det här exemplet visar hur du hittar alla filer som har ett angivet filnamnstillägg (till exempel ".txt") i ett angivet katalogträd. Den visar också hur du returnerar antingen den nyaste eller äldsta filen i trädet baserat på skapandetiden.

Exempel

Module FindFileByExtension  
    Sub Main()  
  
        ' Change the drive\path if necessary  
        Dim root As String = "C:\Program Files\Microsoft Visual Studio 9.0"  
  
        'Take a snapshot of the folder contents  
        Dim dir As New System.IO.DirectoryInfo(root)  
  
        Dim fileList = dir.GetFiles("*.*", System.IO.SearchOption.AllDirectories)  
  
        ' This query will produce the full path for all .txt files  
        ' under the specified folder including subfolders.  
        ' It orders the list according to the file name.  
        Dim fileQuery = From file In fileList _  
                        Where file.Extension = ".txt" _  
                        Order By file.Name _  
                        Select file  
  
        For Each file In fileQuery  
            Console.WriteLine(file.FullName)  
        Next  
  
        ' Create and execute a new query by using  
        ' the previous query as a starting point.  
        ' fileQuery is not executed again until the  
        ' call to Last  
        Dim fileQuery2 = From file In fileQuery _  
                         Order By file.CreationTime _  
                         Select file.Name, file.CreationTime  
  
        ' Execute the query  
        Dim newestFile = fileQuery2.Last  
  
        Console.WriteLine("\r\nThe newest .txt file is {0}. Creation time: {1}", _  
                newestFile.Name, newestFile.CreationTime)  
  
        ' Keep the console window open in debug mode  
        Console.WriteLine("Press any key to exit.")  
        Console.ReadKey()  
  
    End Sub  
End Module

Kompilera koden

Skapa ett Visual Basic-konsolprogramprojekt med en Imports instruktion för System.Linq-namnområdet.

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