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Procedura: Trovare file e directory esistenti nello spazio di memorizzazione isolato

  • Articolo

Per cercare una directory nello spazio di memorizzazione isolato, usare il metodo IsolatedStorageFile.GetDirectoryNames. Questo metodo accetta una stringa che rappresenta un criterio di ricerca. Nel criterio di ricerca è possibile usare sia un solo carattere jolly (?) sia più caratteri jolly (*), ma questi devono apparire nella parte finale del nome. Ad esempio, directory1/*ect* è una stringa di ricerca valida, mentre *ect*/directory2 non lo è.

Per cercare un file, usare il metodo IsolatedStorageFile.GetFileNames. La restrizione relativa ai caratteri jolly nelle stringhe di ricerca applicata a GetDirectoryNames si applica anche a GetFileNames.

Nessuno di questi metodi è ricorsivo. La classe IsolatedStorageFile non fornisce alcun metodo per elencare tutti file o le directory nell'archivio. Tuttavia, i metodi ricorsivi vengono mostrati nell'esempio di codice seguente.

Esempio

L'esempio di codice seguente mostra come creare file e directory in uno spazio di memorizzazione isolato. Prima di tutto, viene recuperato uno spazio di memorizzazione isolato in base all'utente, al dominio e all'assembly, che viene inserito nella variabile isoStore. Viene usato il metodo CreateDirectory per configurare alcune directory diverse e il costruttore IsolatedStorageFileStream(String, FileMode, IsolatedStorageFile) crea alcuni file in queste directory. Il codice esegue quindi il ciclo nei risultati del metodo GetAllDirectories. Questo metodo usa GetDirectoryNames per trovare tutti i nomi di directory nella directory corrente. Questi nomi vengono archiviati in una matrice e quindi il metodo GetAllDirectories chiama se stesso, passando ogni directory trovata. Come risultato, vengono restituiti tutti i nomi di directory in una matrice. Il codice chiama quindi il metodo GetAllFiles. Questo metodo chiama GetAllDirectories per trovare i nomi di tutte le directory e quindi controlla ogni directory per individuare i file usando il metodo GetFileNames. Il risultato viene restituito in una matrice per la visualizzazione.

using namespace System;
using namespace System::IO;
using namespace System::IO::IsolatedStorage;
using namespace System::Collections;
using namespace System::Collections::Generic;

public class FindingExistingFilesAndDirectories
{
public:
    // Retrieves an array of all directories in the store, and
    // displays the results.
    static void Main()
    {
        // This part of the code sets up a few directories and files in the
        // store.
        IsolatedStorageFile^ isoStore = IsolatedStorageFile::GetStore(IsolatedStorageScope::User |
            IsolatedStorageScope::Assembly, (Type ^)nullptr, (Type ^)nullptr);
        isoStore->CreateDirectory("TopLevelDirectory");
        isoStore->CreateDirectory("TopLevelDirectory/SecondLevel");
        isoStore->CreateDirectory("AnotherTopLevelDirectory/InsideDirectory");
        gcnew IsolatedStorageFileStream("InTheRoot.txt", FileMode::Create, isoStore);
        gcnew IsolatedStorageFileStream("AnotherTopLevelDirectory/InsideDirectory/HereIAm.txt",
            FileMode::Create, isoStore);
        // End of setup.

        Console::WriteLine('\r');
        Console::WriteLine("Here is a list of all directories in this isolated store:");

        for each (String^ directory in GetAllDirectories("*", isoStore))
        {
            Console::WriteLine(directory);
        }
        Console::WriteLine('\r');

        // Retrieve all the files in the directory by calling the GetFiles
        // method.

        Console::WriteLine("Here is a list of all the files in this isolated store:");
        for each (String^ file in GetAllFiles("*", isoStore))
        {
            Console::WriteLine(file);
        }

    } // End of Main.

    // Method to retrieve all directories, recursively, within a store.
    static List<String^>^ GetAllDirectories(String^ pattern, IsolatedStorageFile^ storeFile)
    {
        // Get the root of the search string.
        String^ root = Path::GetDirectoryName(pattern);

        if (root != "")
        {
            root += "/";
        }

        // Retrieve directories.
        array<String^>^ directories = storeFile->GetDirectoryNames(pattern);

        List<String^>^ directoryList = gcnew List<String^>(directories);

        // Retrieve subdirectories of matches.
        for (int i = 0, max = directories->Length; i < max; i++)
        {
             String^ directory = directoryList[i] + "/";
             List<String^>^ more = GetAllDirectories (root + directory + "*", storeFile);

             // For each subdirectory found, add in the base path.
             for (int j = 0; j < more->Count; j++)
             {
                 more[j] = directory + more[j];
             }

            // Insert the subdirectories into the list and
            // update the counter and upper bound.
            directoryList->InsertRange(i + 1, more);
            i += more->Count;
            max += more->Count;
        }

        return directoryList;
    }

    static List<String^>^ GetAllFiles(String^ pattern, IsolatedStorageFile^ storeFile)
    {
        // Get the root and file portions of the search string.
        String^ fileString = Path::GetFileName(pattern);
        array<String^>^ files = storeFile->GetFileNames(pattern);

        List<String^>^ fileList = gcnew List<String^>(files);

        // Loop through the subdirectories, collect matches,
        // and make separators consistent.
        for each (String^ directory in GetAllDirectories( "*", storeFile))
        {
            for each (String^ file in storeFile->GetFileNames(directory + "/" + fileString))
            {
                fileList->Add((directory + "/" + file));
            }
        }

        return fileList;
    } // End of GetFiles.
};

int main()
{
    FindingExistingFilesAndDirectories::Main();
}

using System;
using System.IO;
using System.IO.IsolatedStorage;
using System.Collections;
using System.Collections.Generic;

public class FindingExistingFilesAndDirectories
{
    // Retrieves an array of all directories in the store, and
    // displays the results.
    public static void Main()
    {
        // This part of the code sets up a few directories and files in the
        // store.
        IsolatedStorageFile isoStore = IsolatedStorageFile.GetStore(IsolatedStorageScope.User |
            IsolatedStorageScope.Assembly, null, null);
        isoStore.CreateDirectory("TopLevelDirectory");
        isoStore.CreateDirectory("TopLevelDirectory/SecondLevel");
        isoStore.CreateDirectory("AnotherTopLevelDirectory/InsideDirectory");
        isoStore.CreateFile("InTheRoot.txt");
        isoStore.CreateFile("AnotherTopLevelDirectory/InsideDirectory/HereIAm.txt");
        // End of setup.

        Console.WriteLine('\r');
        Console.WriteLine("Here is a list of all directories in this isolated store:");

        foreach (string directory in GetAllDirectories("*", isoStore))
        {
            Console.WriteLine(directory);
        }
        Console.WriteLine('\r');

        // Retrieve all the files in the directory by calling the GetFiles
        // method.

        Console.WriteLine("Here is a list of all the files in this isolated store:");
        foreach (string file in GetAllFiles("*", isoStore)){
            Console.WriteLine(file);
        }
    } // End of Main.

    // Method to retrieve all directories, recursively, within a store.
    public static List<String> GetAllDirectories(string pattern, IsolatedStorageFile storeFile)
    {
        // Get the root of the search string.
        string root = Path.GetDirectoryName(pattern);

        if (root != "")
        {
            root += "/";
        }

        // Retrieve directories.
        List<String> directoryList = new List<String>(storeFile.GetDirectoryNames(pattern));

        // Retrieve subdirectories of matches.
        for (int i = 0, max = directoryList.Count; i < max; i++)
        {
            string directory = directoryList[i] + "/";
            List<String> more = GetAllDirectories(root + directory + "*", storeFile);

            // For each subdirectory found, add in the base path.
            for (int j = 0; j < more.Count; j++)
            {
                more[j] = directory + more[j];
            }

            // Insert the subdirectories into the list and
            // update the counter and upper bound.
            directoryList.InsertRange(i + 1, more);
            i += more.Count;
            max += more.Count;
        }

        return directoryList;
    }

    public static List<String> GetAllFiles(string pattern, IsolatedStorageFile storeFile)
    {
        // Get the root and file portions of the search string.
        string fileString = Path.GetFileName(pattern);

        List<String> fileList = new List<String>(storeFile.GetFileNames(pattern));

        // Loop through the subdirectories, collect matches,
        // and make separators consistent.
        foreach (string directory in GetAllDirectories("*", storeFile))
        {
            foreach (string file in storeFile.GetFileNames(directory + "/" + fileString))
            {
                fileList.Add((directory + "/" + file));
            }
        }

        return fileList;
    } // End of GetFiles.
}

Imports System.IO
Imports System.IO.IsolatedStorage
Imports System.Collections
Imports System.Collections.Generic

Public class FindingExistingFilesAndDirectories
    ' These arrayLists hold the directory and file names as they are found.

    Private Shared directoryList As New List(Of String)
    Private Shared fileList As New List(Of String)

    ' Retrieves an array of all directories in the store, and
    ' displays the results.

    Public Shared Sub Main()
        ' This part of the code sets up a few directories and files in the store.
        Dim isoStore As IsolatedStorageFile = IsolatedStorageFile.GetStore(IsolatedStorageScope.User Or _
            IsolatedStorageScope.Assembly Or IsolatedStorageScope.Domain, Nothing, Nothing)
        isoStore.CreateDirectory("TopLevelDirectory")
        isoStore.CreateDirectory("TopLevelDirectory/SecondLevel")
        isoStore.CreateDirectory("AnotherTopLevelDirectory/InsideDirectory")
        isoStore.CreateFile("InTheRoot.txt")
        isoStore.CreateFile("AnotherTopLevelDirectory/InsideDirectory/HereIAm.txt")
        ' End of setup.

        Console.WriteLine()
        Console.WriteLine("Here is a list of all directories in this isolated store:")

        GetAllDirectories("*", isoStore)
        For Each directory As String In directoryList
            Console.WriteLine(directory)
        Next

        Console.WriteLine()
        Console.WriteLine("Retrieve all the files in the directory by calling the GetFiles method.")

        GetAllFiles(isoStore)
        For Each file As String In fileList
            Console.WriteLine(file)
        Next
    End Sub

    Public Shared Sub GetAllDirectories(ByVal pattern As String, ByVal storeFile As IsolatedStorageFile)
        ' Retrieve directories.
        Dim directories As String() = storeFile.GetDirectoryNames(pattern)

        For Each directory As String In directories
            ' Add the directory to the final list.
            directoryList.Add((pattern.TrimEnd(CChar("*"))) + directory + "/")
            ' Call the method again using directory.
            GetAllDirectories((pattern.TrimEnd(CChar("*")) + directory + "/*"), storeFile)
        Next
    End Sub

    Public Shared Sub GetAllFiles(ByVal storefile As IsolatedStorageFile)
        ' This adds the root to the directory list.
        directoryList.Add("*")
        For Each directory As String In directoryList
            Dim files As String() = storefile.GetFileNames(directory + "*")
            For Each dirfile As String In files
                fileList.Add(dirfile)
            Next
        Next
    End Sub
End Class

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