FileInfo.Open Metode

Referensi

Definisi

Ruang nama:: System.IO

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

Rakitan:: System.IO.FileSystem.dll

Rakitan:: System.Runtime.dll

Rakitan:: mscorlib.dll

Rakitan:: netstandard.dll

Penting

Beberapa informasi terkait produk prarilis yang dapat diubah secara signifikan sebelum dirilis. Microsoft tidak memberikan jaminan, tersirat maupun tersurat, sehubungan dengan informasi yang diberikan di sini.

Membuka file dengan berbagai hak istimewa baca/tulis dan berbagi.

Overload

Open(FileMode)	Membuka file dalam mode yang ditentukan.
Open(FileStreamOptions)	Menginisialisasi instans FileStream baru kelas dengan mode pembuatan yang ditentukan, izin baca/tulis dan berbagi, akses fileStream lainnya dapat memiliki ke file yang sama, ukuran buffer, opsi file tambahan, dan ukuran alokasi.
Open(FileMode, FileAccess)	Membuka file dalam mode yang ditentukan dengan akses baca, tulis, atau baca/tulis.
Open(FileMode, FileAccess, FileShare)	Membuka file dalam mode yang ditentukan dengan akses baca, tulis, atau baca/tulis dan opsi berbagi yang ditentukan.

Open(FileMode)

Sumber:: FileInfo.cs

Sumber:: FileInfo.cs

Sumber:: FileInfo.cs

Membuka file dalam mode yang ditentukan.

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

Parameter

mode: FileMode

Konstanta FileMode yang menentukan mode (misalnya, Open atau Append) untuk membuka file.

Mengembalikan

FileStream

File dibuka dalam mode yang ditentukan, dengan akses baca/tulis dan tidak dibagikan.

Pengecualian

FileNotFoundException

File tidak ditemukan.

UnauthorizedAccessException

File bersifat baca-saja atau merupakan direktori.

DirectoryNotFoundException

Jalur yang ditentukan tidak valid, seperti berada di drive yang tidak dipetakan.

IOException

File sudah terbuka.

Contoh

Contoh berikut membuka file, menambahkan beberapa informasi ke file, dan membaca file.

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.
'
'
'
'
'
'
'
'
'
'
'
'

Lihat juga

Berlaku untuk

Open(FileStreamOptions)

Sumber:: FileInfo.cs

Sumber:: FileInfo.cs

Sumber:: FileInfo.cs

Menginisialisasi instans FileStream baru kelas dengan mode pembuatan yang ditentukan, izin baca/tulis dan berbagi, akses fileStream lainnya dapat memiliki ke file yang sama, ukuran buffer, opsi file tambahan, dan ukuran alokasi.

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

Parameter

options: FileStreamOptions

Objek yang menjelaskan parameter opsional FileStream untuk digunakan.

Mengembalikan

FileStream

FileStream Yang membungkus file yang dibuka.

Keterangan

FileStream(String, FileStreamOptions) untuk informasi tentang pengecualian.

Berlaku untuk

Open(FileMode, FileAccess)

Sumber:: FileInfo.cs

Sumber:: FileInfo.cs

Sumber:: FileInfo.cs

Membuka file dalam mode yang ditentukan dengan akses baca, tulis, atau baca/tulis.

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

Parameter

mode: FileMode

Konstanta FileMode yang menentukan mode (misalnya, Open atau Append) untuk membuka file.

access: FileAccess

Konstanta FileAccess yang menentukan apakah akan membuka file dengan Readakses file , Write, atau ReadWrite .

Mengembalikan

FileStream

Objek FileStream dibuka dalam mode dan akses yang ditentukan, dan tidak dibagikan.

Pengecualian

SecurityException

Pemanggil tidak memiliki izin yang diperlukan.

FileNotFoundException

File tidak ditemukan.

UnauthorizedAccessException

Name bersifat baca-saja atau merupakan direktori.

DirectoryNotFoundException

Jalur yang ditentukan tidak valid, seperti berada di drive yang tidak dipetakan.

IOException

File sudah terbuka.

ArgumentException

Name kosong atau hanya berisi spasi kosong.

ArgumentNullException

Satu atau beberapa argumen null.

Contoh

Contoh berikut membuka file sebagai baca-saja dan membaca dari file.

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
'

Lihat juga

Berlaku untuk

Open(FileMode, FileAccess, FileShare)

Sumber:: FileInfo.cs

Sumber:: FileInfo.cs

Sumber:: FileInfo.cs

Membuka file dalam mode yang ditentukan dengan akses baca, tulis, atau baca/tulis dan opsi berbagi yang ditentukan.

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

Parameter

mode: FileMode

Konstanta FileMode yang menentukan mode (misalnya, Open atau Append) untuk membuka file.

access: FileAccess

Konstanta FileAccess yang menentukan apakah akan membuka file dengan Readakses file , Write, atau ReadWrite .

share: FileShare

Konstanta FileShare yang menentukan tipe akses objek lain FileStream ke file ini.

Mengembalikan

FileStream

Objek FileStream dibuka dengan mode, akses, dan opsi berbagi yang ditentukan.

Pengecualian

SecurityException

Pemanggil tidak memiliki izin yang diperlukan.

FileNotFoundException

File tidak ditemukan.

UnauthorizedAccessException

Name bersifat baca-saja atau merupakan direktori.

DirectoryNotFoundException

Jalur yang ditentukan tidak valid, seperti berada di drive yang tidak dipetakan.

IOException

File sudah terbuka.

ArgumentException

Name kosong atau hanya berisi spasi kosong.

ArgumentNullException

Satu atau beberapa argumen null.

Contoh

Contoh berikut menunjukkan pembukaan file untuk membaca dan menulis, tetapi melarang akses ke pengguna atau proses lain.

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

Lihat juga

Berlaku untuk

FileInfo.Open Metode

Definisi

Overload

Open(FileMode)

Parameter

Mengembalikan

Pengecualian

Contoh

Lihat juga

Berlaku untuk

Open(FileStreamOptions)

Parameter

Mengembalikan

Keterangan

Berlaku untuk

Open(FileMode, FileAccess)

Parameter

Mengembalikan

Pengecualian

Contoh

Lihat juga

Berlaku untuk

Open(FileMode, FileAccess, FileShare)

Parameter

Mengembalikan

Pengecualian

Contoh

Lihat juga

Berlaku untuk

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