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

Definition

Bestimmt, ob der angegebene Pfad auf ein vorhandenes Verzeichnis auf einem Datenträger verweist.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

Parameter

path
String String String String

Der zu testende Pfad.The path to test.

Gibt zurück

true, wenn sich path auf ein vorhandenes Verzeichnis bezieht; false, wenn ein Verzeichnis nicht vorhanden ist, oder wenn beim Versuch festzustellen, ob ein angegebenes Verzeichnis vorhanden ist, ein Fehler auftritt.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.

Beispiele

Im folgende Beispiel wird ein Array von Datei- bzw. Verzeichnisnamen in der Befehlszeile, bestimmt, welche Art von Namen dabei handelt es sich, verarbeitet sie entsprechend.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

Hinweise

Die path Parameter dürfen relativer oder absoluter Pfad angegeben werden.The path parameter is permitted to specify relative or absolute path information. Relativer Pfad wird relativ zum aktuellen Arbeitsverzeichnis interpretiert.Relative path information is interpreted as relative to the current working directory.

Nachgestellte Leerzeichen entfernt werden, am Ende der path -Parameter vor dem Überprüfen, ob das Verzeichnis vorhanden ist.Trailing spaces are removed from the end of the path parameter before checking whether the directory exists.

Die path Parameter wird nicht beachtet.The path parameter is not case-sensitive.

Wenn Sie nicht mindestens über eine nur-Lese Berechtigung in das Verzeichnis, verfügen die Exists Methode zurück false.If you do not have at a minimum read-only permission to the directory, the Exists method will return false.

Die Exists Methodenrückgabe false Wenn ein Fehler auftritt, bei dem Versuch, um festzustellen, ob die angegebene Datei vorhanden ist.The Exists method returns false if any error occurs while trying to determine if the specified file exists. Dies kann auftreten, in Situationen, in denen Auslösen von Ausnahmen, z. B. ein Dateiname ungültige Zeichen oder zu viele Zeichen, eine fehlerhafte oder fehlende Datenträger übergeben oder wenn der Aufrufer keine Berechtigung zum Lesen der Datei.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.

Sicherheit

FileIOPermission
zum Lesen von Dateien.for reading files. Zugeordnete Enumeration: ReadAssociated enumeration: Read

Gilt für:

Siehe auch