FileInfo.Open Méthode

Référence

Définition

Espace de noms:: System.IO

Assemblys:: mscorlib.dll, System.IO.FileSystem.dll

Assembly:: System.IO.FileSystem.dll

Assembly:: System.Runtime.dll

Assembly:: mscorlib.dll

Assembly:: netstandard.dll

Important

Certaines informations portent sur la préversion du produit qui est susceptible d’être en grande partie modifiée avant sa publication. Microsoft exclut toute garantie, expresse ou implicite, concernant les informations fournies ici.

Ouvre un fichier avec différents privilèges de lecture/écriture et de partage.

Surcharges

Open(FileMode)	Ouvre un fichier dans le mode spécifié.
Open(FileStreamOptions)	Initialise une nouvelle instance de la classe avec le FileStream mode de création, l’autorisation de lecture/écriture et de partage spécifiée, l’accès d’autres FileStreams au même fichier, la taille de la mémoire tampon, les options de fichier supplémentaires et la taille d’allocation.
Open(FileMode, FileAccess)	Ouvre un fichier dans le mode spécifié, avec accès en lecture, en écriture ou en lecture/écriture.
Open(FileMode, FileAccess, FileShare)	Ouvre un fichier dans le mode spécifié, avec accès en lecture, en écriture ou en lecture/écriture, et l'option de partage spécifiée.

Open(FileMode)

Source:: FileInfo.cs

Source:: FileInfo.cs

Source:: FileInfo.cs

Ouvre un fichier dans le mode spécifié.

public:
 System::IO::FileStream ^ Open(System::IO::FileMode mode);

public System.IO.FileStream Open (System.IO.FileMode mode);

member this.Open : System.IO.FileMode -> System.IO.FileStream

Public Function Open (mode As FileMode) As FileStream

Paramètres

mode: FileMode

Constante FileMode spécifiant le mode (par exemple Open ou Append) dans lequel ouvrir le fichier.

Retours

FileStream

Fichier ouvert dans le mode spécifié, avec accès en lecture/écriture et non partagé.

Exceptions

FileNotFoundException

Le fichier est introuvable.

UnauthorizedAccessException

Le fichier est en lecture seule ou est un répertoire.

DirectoryNotFoundException

Le chemin spécifié n’est pas valide, par exemple si l’emplacement est un lecteur non mappé.

IOException

Le fichier est déjà ouvert.

Exemples

L’exemple suivant ouvre un fichier, ajoute des informations au fichier et lit le fichier.

using namespace System;
using namespace System::IO;
using namespace System::Text;

int main()
{
   String^ path = "c:\\MyTest.txt";
   FileInfo^ fi = gcnew FileInfo( path );
   
   // Delete the file if it exists.
   if (  !fi->Exists )
   {
      //Create the file.
      FileStream^ fs = fi->Create();
      try
      {
         array<Byte>^info = (gcnew UTF8Encoding( true ))->GetBytes( "This is some text in the file." );
         
         //Add some information to the file.
         fs->Write( info, 0, info->Length );
      }
      finally
      {
         if ( fs )
            delete (IDisposable^)fs;
      }
   }

   //Open the stream and read it back.
   FileStream^ fs = fi->Open( FileMode::Open );
   try
   {
      array<Byte>^b = gcnew array<Byte>(1024);
      UTF8Encoding^ temp = gcnew UTF8Encoding( true );
      while ( fs->Read( b, 0, b->Length ) > 0 )
      {
         Console::WriteLine( temp->GetString( b ) );
      }
   }
   finally
   {
      if ( fs )
         delete (IDisposable^)fs;
   }
}

//This code produces output similar to the following; 
//results may vary based on the computer/file structure/etc.:
//
//This is some text in the file.
//
//
//
//
//
//
//
//
//
//
//
//
//

using System;
using System.IO;
using System.Text;

class Test
{
    
    public static void Main()
    {
        string path = @"c:\MyTest.txt";
        FileInfo fi = new FileInfo(path);

        // Delete the file if it exists.
        if (!fi.Exists)
        {
            //Create the file.
            using (FileStream fs = fi.Create())
            {
                Byte[] info = new UTF8Encoding(true).GetBytes("This is some text in the file.");
                //Add some information to the file.
                fs.Write(info, 0, info.Length);
            }
        }

        //Open the stream and read it back.
        using (FileStream fs = fi.Open(FileMode.Open))
        {
            byte[] b = new byte[1024];
            UTF8Encoding temp = new UTF8Encoding(true);
            while (fs.Read(b,0,b.Length) > 0)
            {
                Console.WriteLine(temp.GetString(b));
            }
        }
    }
}
//This code produces output similar to the following;
//results may vary based on the computer/file structure/etc.:
//
//This is some text in the file.
//
//
//
//
//
//
//
//
//
//
//
//

Imports System.IO
Imports System.Text

Public Class Test

    Public Shared Sub Main()
        Dim path As String = "c:\temp\MyTest.txt"
        Dim fi As FileInfo = New FileInfo(path)
        Dim fs As FileStream

        ' Delete the file if it exists.
        If fi.Exists = False Then
            'Create the file.
            fs = fi.Create()
            Dim info As Byte() = New UTF8Encoding(True).GetBytes("This is some text in the file.")
            'Add some information to the file.
            fs.Write(info, 0, info.Length)
            fs.Close()
        End If

        'Open the stream and read it back.
        fs = fi.Open(FileMode.Open)
        Dim b(1023) As Byte
        Dim temp As UTF8Encoding = New UTF8Encoding(True)
        Do While fs.Read(b, 0, b.Length) > 0
            Console.WriteLine(temp.GetString(b))
        Loop
        fs.Close()
    End Sub
End Class
'This code produces output similar to the following; 
'results may vary based on the computer/file structure/etc.:
'
'This is some text in the file.
'
'
'
'
'
'
'
'
'
'
'
'

Voir aussi

S’applique à

Open(FileStreamOptions)

Source:: FileInfo.cs

Source:: FileInfo.cs

Source:: FileInfo.cs

Initialise une nouvelle instance de la classe avec le FileStream mode de création, l’autorisation de lecture/écriture et de partage spécifiée, l’accès d’autres FileStreams au même fichier, la taille de la mémoire tampon, les options de fichier supplémentaires et la taille d’allocation.

public:
 System::IO::FileStream ^ Open(System::IO::FileStreamOptions ^ options);

public System.IO.FileStream Open (System.IO.FileStreamOptions options);

member this.Open : System.IO.FileStreamOptions -> System.IO.FileStream

Public Function Open (options As FileStreamOptions) As FileStream

Paramètres

options: FileStreamOptions

Objet qui décrit les paramètres facultatifs FileStream à utiliser.

Retours

FileStream

FileStream qui encapsule le fichier ouvert.

Remarques

FileStream(String, FileStreamOptions) pour plus d’informations sur les exceptions.

S’applique à

Open(FileMode, FileAccess)

Source:: FileInfo.cs

Source:: FileInfo.cs

Source:: FileInfo.cs

Ouvre un fichier dans le mode spécifié, avec accès en lecture, en écriture ou en lecture/écriture.

public:
 System::IO::FileStream ^ Open(System::IO::FileMode mode, System::IO::FileAccess access);

public System.IO.FileStream Open (System.IO.FileMode mode, System.IO.FileAccess access);

member this.Open : System.IO.FileMode * System.IO.FileAccess -> System.IO.FileStream

Public Function Open (mode As FileMode, access As FileAccess) As FileStream

Paramètres

mode: FileMode

Constante FileMode spécifiant le mode (par exemple Open ou Append) dans lequel ouvrir le fichier.

access: FileAccess

Constante FileAccess spécifiant si le fichier doit être ouvert avec l'accès Read, Write ou ReadWrite.

Retours

FileStream

Objet FileStream ouvert dans le mode et l'accès spécifiés, et non partagé.

Exceptions

SecurityException

L'appelant n'a pas l'autorisation requise.

FileNotFoundException

Le fichier est introuvable.

UnauthorizedAccessException

Name est en lecture seule ou est un répertoire.

DirectoryNotFoundException

Le chemin spécifié n’est pas valide, par exemple si l’emplacement est un lecteur non mappé.

IOException

Le fichier est déjà ouvert.

ArgumentException

Name est vide ou ne contient que des espaces blancs.

ArgumentNullException

Un ou plusieurs arguments sont null.

Exemples

L’exemple suivant ouvre un fichier en lecture seule et lit à partir du fichier.

using namespace System;
using namespace System::IO;
using namespace System::Text;

int main()
{
   String^ path = "c:\\MyTest.txt";
   FileInfo^ fi = gcnew FileInfo( path );
   
   // Delete the file if it exists.
   if (  !fi->Exists )
   {
      
      //Create the file.
      FileStream^ fs = fi->Create();
      try
      {
         array<Byte>^info = (gcnew UTF8Encoding( true ))->GetBytes( "This is some text in the file." );
         
         //Add some information to the file.
         fs->Write( info, 0, info->Length );
      }
      finally
      {
         if ( fs )
            delete (IDisposable^)fs;
      }
   }

   //Open the stream and read it back.
   FileStream^ fs = fi->Open( FileMode::Open, FileAccess::Read );
   try
   {
      array<Byte>^b = gcnew array<Byte>(1024);
      UTF8Encoding^ temp = gcnew UTF8Encoding( true );
      while ( fs->Read( b, 0, b->Length ) > 0 )
      {
         Console::WriteLine( temp->GetString( b ) );
      }
      try
      {
         //Try to write to the file.
         fs->Write( b, 0, b->Length );
      }
      catch ( Exception^ e ) 
      {
         Console::WriteLine( "Writing was disallowed, as expected: {0}", e );
      }
   }
   finally
   {
      if ( fs )
         delete (IDisposable^)fs;
   }
}
//This code produces output similar to the following; 
//results may vary based on the computer/file structure/etc.:
//
//This is some text in the file.
//
//
//
//
//
//
//
//
//
//
//
//
//Writing was disallowed, as expected: System.NotSupportedException: Stream does 
//not support writing.
//   at System.IO.__Error.WriteNotSupported()
//   at System.IO.FileStream.Write(Byte[] array, Int32 offset, Int32 count)
//   at main() in c:\documents and settings\MyComputer\my documents\
//visual studio 2005\projects\finfo open2\finfo open2\
//cpp_console_application.cpp:line 46

using System;
using System.IO;
using System.Text;

class Test
{
    
    public static void Main()
    {
        string path = @"c:\MyTest.txt";
        FileInfo fi = new FileInfo(path);

        // Delete the file if it exists.
        if (!fi.Exists)
        {
            //Create the file.
            using (FileStream fs = fi.Create())
            {
                Byte[] info = new UTF8Encoding(true).GetBytes("This is some text in the file.");
                //Add some information to the file.
                fs.Write(info, 0, info.Length);
            }
        }

        //Open the stream and read it back.
        using (FileStream fs = fi.Open(FileMode.Open, FileAccess.Read))
        {
            byte[] b = new byte[1024];
            UTF8Encoding temp = new UTF8Encoding(true);
            while (fs.Read(b,0,b.Length) > 0)
            {
                Console.WriteLine(temp.GetString(b));
            }

            try
            {
                //Try to write to the file.
                fs.Write(b,0,b.Length);
            }
            catch (Exception e)
            {
                Console.WriteLine("Writing was disallowed, as expected: {0}",
                    e.ToString());
            }
        }
    }
}
//This code produces output similar to the following;
//results may vary based on the computer/file structure/etc.:
//
//This is some text in the file.
//
//
//
//
//
//
//
//
//
//
//
//
//Writing was disallowed, as expected: System.NotSupportedException: Stream does
//not support writing.
//   at System.IO.__Error.WriteNotSupported()
//   at System.IO.FileStream.Write(Byte[] array, Int32 offset, Int32 count)
//   at Test.Main() in C:\Documents and Settings\My Computer\My Documents\
//Visual Studio 2005\Projects\finfo open2\finfo open2\Program.cs:line 39

imports System.IO
imports System.Text

Public Class Test
    Public Shared Sub Main()
        Dim path As String = "c:\MyTest.txt"
        Dim fi As FileInfo = new FileInfo(path)
        Dim fs As FileStream

        ' Delete the file if it exists.
        If fi.Exists = False
            'Create the file.
            fs = fi.Create()
            Dim info As Byte() = _
                    New UTF8Encoding(true).GetBytes( _
                        "This is some text in the file.")

            'Add some information to the file.
            fs.Write(info, 0, info.Length)
            fs.Close()
        End If

        'Open the stream and read it back.
        fs = fi.Open(FileMode.Open, FileAccess.Read)
        Dim b(1023) As byte
        Dim temp As UTF8Encoding = New UTF8Encoding(true)

        Do While fs.Read(b,0,b.Length) > 0
            Console.WriteLine(temp.GetString(b))
        Loop
            Try
                fs.Write(b,0,b.Length)
                Catch e As Exception
                Console.WriteLine("Writing was disallowed, as expected: {0}", e.ToString())
            End Try
        fs.Close()
    End Sub
End Class
'This code produces output similar to the following; 
'results may vary based on the computer/file structure/etc.:
'
'This is some text in the file.
'
'
'
'
'
'
'
'
'
'
'
'
'Writing was disallowed, as expected: System.NotSupportedException: Stream does 
'not support writing.
'   at System.IO.__Error.WriteNotSupported()
'   at System.IO.FileStream.Write(Byte[] array, Int32 offset, Int32 count)
'   at VB_Console_Application.Test.Main() in C:\Documents and Settings\MyComputer
'\My Documents\Visual Studio 2005\Projects\finfo open2\finfo open2\Module1.vb:line 34
'

Voir aussi

S’applique à

Open(FileMode, FileAccess, FileShare)

Source:: FileInfo.cs

Source:: FileInfo.cs

Source:: FileInfo.cs

Ouvre un fichier dans le mode spécifié, avec accès en lecture, en écriture ou en lecture/écriture, et l'option de partage spécifiée.

public:
 System::IO::FileStream ^ Open(System::IO::FileMode mode, System::IO::FileAccess access, System::IO::FileShare share);

public System.IO.FileStream Open (System.IO.FileMode mode, System.IO.FileAccess access, System.IO.FileShare share);

member this.Open : System.IO.FileMode * System.IO.FileAccess * System.IO.FileShare -> System.IO.FileStream

Public Function Open (mode As FileMode, access As FileAccess, share As FileShare) As FileStream

Paramètres

mode: FileMode

Constante FileMode spécifiant le mode (par exemple Open ou Append) dans lequel ouvrir le fichier.

access: FileAccess

Constante FileAccess spécifiant si le fichier doit être ouvert avec l'accès Read, Write ou ReadWrite.

share: FileShare

Constante FileShare spécifiant le type d'accès qu'ont d'autres objets FileStream à ce fichier.

Retours

FileStream

Objet FileStream ouvert avec le mode, l'accès et les options de partage spécifiés.

Exceptions

SecurityException

L'appelant n'a pas l'autorisation requise.

FileNotFoundException

Le fichier est introuvable.

UnauthorizedAccessException

Name est en lecture seule ou est un répertoire.

DirectoryNotFoundException

Le chemin spécifié n’est pas valide, par exemple si l’emplacement est un lecteur non mappé.

IOException

Le fichier est déjà ouvert.

ArgumentException

Name est vide ou ne contient que des espaces blancs.

ArgumentNullException

Un ou plusieurs arguments sont null.

Exemples

L’exemple suivant montre comment ouvrir un fichier pour la lecture et l’écriture, mais interdire l’accès à d’autres utilisateurs ou processus.

using namespace System;
using namespace System::IO;
int main()
{
   
   // Open an existing file, or create a new one.
   FileInfo^ fi = gcnew FileInfo( "temp.txt" );
   
   // Open the file just specified such that no one else can use it.
   FileStream^ fs = fi->Open( FileMode::OpenOrCreate, FileAccess::ReadWrite, FileShare::None );
   
   // Create another reference to the same file.
   FileInfo^ nextfi = gcnew FileInfo( "temp.txt" );
   try
   {
      
      // Try opening the same file, which was locked by the previous process.
      nextfi->Open( FileMode::OpenOrCreate, FileAccess::Read );
      Console::WriteLine( "The file was not locked, and was opened by a second process." );
   }
   catch ( IOException^ ) 
   {
      Console::WriteLine( "The file could not be opened because it was locked by another process." );
   }
   catch ( Exception^ e ) 
   {
      Console::WriteLine( e );
   }

   
   // Close the file so it can be deleted.
   fs->Close();
}
//This code produces output similar to the following; 
//results may vary based on the computer/file structure/etc.:
//
//The file could not be opened because it was locked by another process.

using System;
using System.IO;

public class OpenTest
{
    public static void Main()
    {
        // Open an existing file, or create a new one.
        FileInfo fi = new FileInfo("temp.txt");

        // Open the file just specified such that no one else can use it.
        FileStream fs = fi.Open( FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.None );

        // Create another reference to the same file.
        FileInfo nextfi = new FileInfo("temp.txt");

        try
        {
            // Try opening the same file, which was locked by the previous process.
            nextfi.Open( FileMode.OpenOrCreate, FileAccess.Read );

            Console.WriteLine("The file was not locked, and was opened by a second process.");
        }
        catch (IOException)
        {
            Console.WriteLine("The file could not be opened because it was locked by another process.");
        }
        catch (Exception e)
        {
            Console.WriteLine(e.ToString());
        }

        // Close the file so it can be deleted.
        fs.Close();
    }
}

//This code produces output similar to the following;
//results may vary based on the computer/file structure/etc.:
//
//The file could not be opened because it was locked by another process.

Imports System.IO

Public Class OpenTest

    Public Shared Sub Main()
        ' Open an existing file, or create a new one.
        Dim fi As New FileInfo("temp.txt")

        ' Open the file just specified such that no one else can use it.
        Dim fs As FileStream = fi.Open(FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.None)

        ' Create another reference to the same file.
        Dim nextfi As New FileInfo("temp.txt")

        Try
            ' Try opening the same file, which was locked by the previous process.
            nextfi.Open(FileMode.OpenOrCreate, FileAccess.Read)
            Console.WriteLine("The file was not locked, and was opened by a second process.")
        Catch i as IOException
            Console.WriteLine(i.ToString())
        Catch e As Exception
            Console.WriteLine(e.ToString())
        End Try

        ' Close the file so it can be deleted.
        fs.Close()
    End Sub
End Class
'This code produces output similar to the following; 
'results may vary based on the computer/file structure/etc.:
'
'System.IO.IOException: The process cannot access the file 
''C:\Documents and Settings\mydirectory\My Documents\Visual Studio 2005
'\Projects\fileinfoopen\fileinfoopen\obj\Release\temp.txt' 
'because it is being used by another process.
'at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
'at System.IO.FileStream.Init(String path, FileMode mode, FileAccess access, 
'Int32 rights, Boolean useRights, FileShare share, Int32 bufferSize, FileOptions
'options, SECURITY_ATTRIBUTES secAttrs, String msgPath, Boolean bFromProxy)
'at System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access,
'FileShare share) at System.IO.FileInfo.Open(FileMode mode, FileAccess access)
'at VB_Console_Application.OpenTest.Main() in C:\Documents and Settings
'\mydirectory\My Documents\Visual Studio 2005\Projects\VB_Console_Application
'\VB_Console_Application\Module1.vb:line 19

Voir aussi

S’applique à

Partager via

FileInfo.Open Méthode

Définition

Surcharges

Open(FileMode)

Paramètres

Retours

Exceptions

Exemples

Voir aussi

S’applique à

Open(FileStreamOptions)

Paramètres

Retours

Remarques

S’applique à

Open(FileMode, FileAccess)

Paramètres

Retours

Exceptions

Exemples

Voir aussi

S’applique à

Open(FileMode, FileAccess, FileShare)

Paramètres

Retours

Exceptions

Exemples

Voir aussi

S’applique à

Ressources supplémentaires