Directory.Exists(String) Directory.Exists(String) Directory.Exists(String) Directory.Exists(String) Method

Definizione

Determina se il percorso specificato fa riferimento a una directory esistente sul disco.Determines whether the given path refers to an existing directory on disk.

public:
 static bool Exists(System::String ^ path);
public static bool Exists (string path);
static member Exists : string -> bool
Public Shared Function Exists (path As String) As Boolean

Parametri

path
String String String String

Percorso da testare.The path to test.

Restituisce

true se path fa riferimento a una directory esistente; false se la directory non esiste o si verifica un errore durante il tentativo di determinare se la directory specificata esiste.true if path refers to an existing directory; false if the directory does not exist or an error occurs when trying to determine if the specified directory exists.

Esempi

L'esempio seguente accetta una matrice di nomi di file o directory nella riga di comando, determina il tipo di nome è e lo elabora in modo appropriato.The following example takes an array of file or directory names on the command line, determines what kind of name it is, and processes it appropriately.

// For File::Exists, Directory::Exists
using namespace System;
using namespace System::IO;
using namespace System::Collections;

// Insert logic for processing found files here.
void ProcessFile( String^ path )
{
   Console::WriteLine( "Processed file '{0}'.", path );
}


// Process all files in the directory passed in, recurse on any directories 
// that are found, and process the files they contain.
void ProcessDirectory( String^ targetDirectory )
{
   
   // Process the list of files found in the directory.
   array<String^>^fileEntries = Directory::GetFiles( targetDirectory );
   IEnumerator^ files = fileEntries->GetEnumerator();
   while ( files->MoveNext() )
   {
      String^ fileName = safe_cast<String^>(files->Current);
      ProcessFile( fileName );
   }

   
   // Recurse into subdirectories of this directory.
   array<String^>^subdirectoryEntries = Directory::GetDirectories( targetDirectory );
   IEnumerator^ dirs = subdirectoryEntries->GetEnumerator();
   while ( dirs->MoveNext() )
   {
      String^ subdirectory = safe_cast<String^>(dirs->Current);
      ProcessDirectory( subdirectory );
   }
}

int main( int argc, char *argv[] )
{
   for ( int i = 1; i < argc; i++ )
   {
      String^ path = gcnew String(argv[ i ]);
      if ( File::Exists( path ) )
      {
         
         // This path is a file
         ProcessFile( path );
      }
      else
      if ( Directory::Exists( path ) )
      {
         
         // This path is a directory
         ProcessDirectory( path );
      }
      else
      {
         Console::WriteLine( "{0} is not a valid file or directory.", path );
      }

   }
}

// For File.Exists, Directory.Exists
using System;
using System.IO;
using System.Collections;

public class RecursiveFileProcessor 
{
    public static void Main(string[] args) 
    {
        foreach(string path in args) 
        {
            if(File.Exists(path)) 
            {
                // This path is a file
                ProcessFile(path); 
            }               
            else if(Directory.Exists(path)) 
            {
                // This path is a directory
                ProcessDirectory(path);
            }
            else 
            {
                Console.WriteLine("{0} is not a valid file or directory.", path);
            }        
        }        
    }


    // Process all files in the directory passed in, recurse on any directories 
    // that are found, and process the files they contain.
    public static void ProcessDirectory(string targetDirectory) 
    {
        // Process the list of files found in the directory.
        string [] fileEntries = Directory.GetFiles(targetDirectory);
        foreach(string fileName in fileEntries)
            ProcessFile(fileName);

        // Recurse into subdirectories of this directory.
        string [] subdirectoryEntries = Directory.GetDirectories(targetDirectory);
        foreach(string subdirectory in subdirectoryEntries)
            ProcessDirectory(subdirectory);
    }
        
    // Insert logic for processing found files here.
    public static void ProcessFile(string path) 
    {
        Console.WriteLine("Processed file '{0}'.", path);	    
    }
}
' For File.Exists, Directory.Exists 

Imports System
Imports System.IO
Imports System.Collections

Public Class RecursiveFileProcessor

    Public Overloads Shared Sub Main(ByVal args() As String)
        Dim path As String
        For Each path In args
            If File.Exists(path) Then
                ' This path is a file.
                ProcessFile(path)
            Else
                If Directory.Exists(path) Then
                    ' This path is a directory.
                    ProcessDirectory(path)
                Else
                    Console.WriteLine("{0} is not a valid file or directory.", path)
                End If
            End If
        Next path
    End Sub 'Main


    ' Process all files in the directory passed in, recurse on any directories 
    ' that are found, and process the files they contain.
    Public Shared Sub ProcessDirectory(ByVal targetDirectory As String)
        Dim fileEntries As String() = Directory.GetFiles(targetDirectory)
        ' Process the list of files found in the directory.
        Dim fileName As String
        For Each fileName In fileEntries
            ProcessFile(fileName)

        Next fileName
        Dim subdirectoryEntries As String() = Directory.GetDirectories(targetDirectory)
        ' Recurse into subdirectories of this directory.
        Dim subdirectory As String
        For Each subdirectory In subdirectoryEntries
            ProcessDirectory(subdirectory)
        Next subdirectory

    End Sub 'ProcessDirectory

    ' Insert logic for processing found files here.
    Public Shared Sub ProcessFile(ByVal path As String)
        Console.WriteLine("Processed file '{0}'.", path)
    End Sub 'ProcessFile
End Class 'RecursiveFileProcessor

Commenti

Il path parametro è consentito specificare le informazioni sul percorso relativo o assoluto.The path parameter is permitted to specify relative or absolute path information. Informazioni sul percorso relativo è interpretati come relativo alla directory di lavoro corrente.Relative path information is interpreted as relative to the current working directory.

Gli spazi finali vengono rimossi dalla fine del path parametro prima della verifica dell'esistenza della directory.Trailing spaces are removed from the end of the path parameter before checking whether the directory exists.

Il path parametro non distinzione maiuscole/minuscole.The path parameter is not case-sensitive.

Se non è in un'autorizzazione minima di sola lettura nella directory, il Exists metodo restituirà false.If you do not have at a minimum read-only permission to the directory, the Exists method will return false.

Il Exists restituzione del metodo false se si verifica un errore durante il tentativo di determinare se il file specificato esiste.The Exists method returns false if any error occurs while trying to determine if the specified file exists. Ciò può verificarsi nelle situazioni che generano eccezioni, ad esempio passando un nome di file con caratteri non validi o troppi caratteri, un disco mancante o non superato o se il chiamante non dispone dell'autorizzazione per leggere il file.This can occur in situations that raise exceptions such as passing a file name with invalid characters or too many characters, a failing or missing disk, or if the caller does not have permission to read the file.

Sicurezza

FileIOPermission
per la lettura dei file.for reading files. Enumerazione associata: ReadAssociated enumeration: Read

Si applica a

Vedi anche