FileStream Class

[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]

Exposes a Stream around a file, supporting both synchronous and asynchronous read and write operations.

Inheritance Hierarchy

System..::.Object
System.IO..::.Stream
System.IO..::.FileStream
System.IO.IsolatedStorage..::.IsolatedStorageFileStream

Namespace: System.IO
Assembly: mscorlib (in mscorlib.dll)

Syntax

Public Class FileStream _
    Inherits Stream
public class FileStream : Stream

The FileStream type exposes the following members.

Constructors

Name Description
FileStream(String, FileMode) Initializes a new instance of the FileStream class with the specified path and creation mode.
FileStream(String, FileMode, FileAccess) Initializes a new instance of the FileStream class with the specified path, creation mode, and read/write permission.
FileStream(String, FileMode, FileAccess, FileShare) Initializes a new instance of the FileStream class with the specified path, creation mode, read/write permission, and sharing permission.
FileStream(String, FileMode, FileAccess, FileShare, Int32) Initializes a new instance of the FileStream class with the specified path, creation mode, read/write and sharing permission, and buffer size.

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Properties

Name Description
CanRead Gets a value indicating whether the current stream supports reading. (Overrides Stream..::.CanRead.)
CanSeek Gets a value indicating whether the current stream supports seeking. (Overrides Stream..::.CanSeek.)
CanTimeout Gets a value that determines whether the current stream can time out. (Inherited from Stream.)
CanWrite Gets a value indicating whether the current stream supports writing. (Overrides Stream..::.CanWrite.)
Length Gets the length in bytes of the stream. (Overrides Stream..::.Length.)
Name Gets the name of the file stream that was passed to the constructor.
Position Gets or sets the current position of this stream. (Overrides Stream..::.Position.)
ReadTimeout Gets or sets a value, in miliseconds, that determines how long the stream will attempt to read before timing out. (Inherited from Stream.)
WriteTimeout Gets or sets a value, in miliseconds, that determines how long the stream will attempt to write before timing out. (Inherited from Stream.)

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Methods

Name Description
BeginRead Begins an asynchronous read. (Overrides Stream..::.BeginRead(array<Byte>[]()[], Int32, Int32, AsyncCallback, Object).)
BeginWrite Begins an asynchronous write. (Overrides Stream..::.BeginWrite(array<Byte>[]()[], Int32, Int32, AsyncCallback, Object).)
Close Closes the current stream and releases any resources (such as sockets and file handles) associated with the current stream. (Inherited from Stream.)
CopyTo(Stream) Reads all the bytes from the current stream and writes them to the destination stream. (Inherited from Stream.)
CopyTo(Stream, Int32) Reads all the bytes from the current stream and writes them to a destination stream, using a specified buffer size. (Inherited from Stream.)
CopyToAsync(Stream) Asynchronously reads the bytes from the current stream and writes them to another stream. (Inherited from Stream.)
CopyToAsync(Stream, Int32) Asynchronously reads the bytes from the current stream and writes them to another stream, using a specified buffer size. (Inherited from Stream.)
CopyToAsync(Stream, Int32, CancellationToken) Asynchronously reads the bytes from the current stream and writes them to another stream, using a specified buffer size and cancellation token. (Inherited from Stream.)
Dispose()()() Releases all resources used by the Stream. (Inherited from Stream.)
Dispose(Boolean) Releases the unmanaged resources used by the FileStream and optionally releases the managed resources. (Overrides Stream..::.Dispose(Boolean).)
EndRead Waits for the pending asynchronous read to complete. (Overrides Stream..::.EndRead(IAsyncResult).)
EndWrite Ends an asynchronous write, blocking until the I/O operation has completed. (Overrides Stream..::.EndWrite(IAsyncResult).)
Equals(Object) Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Finalize Ensures that resources are freed and other cleanup operations are performed when the garbage collector reclaims the FileStream. (Overrides Object..::.Finalize()()().)
Flush()()() Clears all buffers for this stream and causes any buffered data to be written to the file system. (Overrides Stream..::.Flush()()().)
Flush(Boolean) Clears buffers for this stream and causes any buffered data to be written to the file, and also clears all intermediate file buffers.
FlushAsync()()() Asynchronously clears all buffers for this stream and causes any buffered data to be written to the underlying device. (Inherited from Stream.)
FlushAsync(CancellationToken) Asynchronously clears all buffers for this stream, causes any buffered data to be written to the underlying device, and monitors cancellation requests. (Inherited from Stream.)
GetHashCode Serves as a hash function for a particular type. (Inherited from Object.)
GetType Gets the Type of the current instance. (Inherited from Object.)
MemberwiseClone Creates a shallow copy of the current Object. (Inherited from Object.)
Read Reads a block of bytes from the stream and writes the data in a given buffer. (Overrides Stream..::.Read(array<Byte>[]()[], Int32, Int32).)
ReadAsync(array<Byte>[]()[], Int32, Int32) Asynchronously reads a sequence of bytes from the current stream and advances the position within the stream by the number of bytes read. (Inherited from Stream.)
ReadAsync(array<Byte>[]()[], Int32, Int32, CancellationToken) Asynchronously reads a sequence of bytes from the current stream, advances the position within the stream by the number of bytes read, and monitors cancellation requests. (Inherited from Stream.)
ReadByte Reads a byte from the file and advances the read position one byte. (Overrides Stream..::.ReadByte()()().)
Seek Sets the current position of this stream to the given value. (Overrides Stream..::.Seek(Int64, SeekOrigin).)
SetLength Sets the length of this stream to the given value. (Overrides Stream..::.SetLength(Int64).)
ToString Returns a string that represents the current object. (Inherited from Object.)
Write Writes a block of bytes to this stream using data from a buffer. (Overrides Stream..::.Write(array<Byte>[]()[], Int32, Int32).)
WriteAsync(array<Byte>[]()[], Int32, Int32) Asynchronously writes a sequence of bytes to the current stream and advances the current position within this stream by the number of bytes written. (Inherited from Stream.)
WriteAsync(array<Byte>[]()[], Int32, Int32, CancellationToken) Asynchronously writes a sequence of bytes to the current stream, advances the current position within this stream by the number of bytes written, and monitors cancellation requests. (Inherited from Stream.)
WriteByte Writes a byte to the current position in the file stream. (Overrides Stream..::.WriteByte(Byte).)

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Extension Methods

Name Description
AsInputStream (Defined by WindowsRuntimeStreamExtensions.)
AsOutputStream (Defined by WindowsRuntimeStreamExtensions.)

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Remarks

Version Notes

Windows Phone

This type is present to support the .NET Compact Framework infrastructure in Windows Phone, and it is not intended to be used in your application code.

Examples

The following example displays an image picked at random from the user's My Pictures folder. It uses the DirectoryInfo class to obtain an enumerable collection of FileInfo objects that represent files that have a .jpg or .png extension. That collection is used to construct a List<(Of <(T>)>) collection so that an index can be used to select a file that corresponds to the random number.

The example then creates a bitmap image by using the FileStream class and sets it as the source for an Image control (named MyImage). For information on how to compile and run this example code, see Building examples that have static TextBlock controls for Windows Phone 8.

Private Sub LoadImage()


        Dim di As New DirectoryInfo(Environment.GetFolderPath(Environment.SpecialFolder.MyPictures))

        Dim files = From f In di.EnumerateFiles() _
            Where f.Extension.ToLower() = ".jpg" OrElse f.Extension = ".png" _
            Select f

        Dim max As Integer = files.Count() + 1

        Dim rnd As New Random()
        Dim r As Integer = rnd.[Next](0, max)

        Dim pics As New List(Of FileInfo)(files)

        Dim randpic As String = pics(r).FullName

        Dim img As New BitmapImage()
        img.SetSource(New FileStream(randpic, FileMode.Open))


        MyImage.Source = img

End Sub
private void LoadImage()
{

    DirectoryInfo di = new DirectoryInfo(Environment.GetFolderPath(
        Environment.SpecialFolder.MyPictures));

    var files = from f in di.EnumerateFiles()
                where f.Extension.ToLower() == ".jpg" || 
                    f.Extension == ".png"
                select f;

    int max = files.Count() + 1;

    Random rnd = new Random();
    int r = rnd.Next(0, max);

    List<FileInfo> pics = new List<FileInfo>(files);

    string randpic = pics[r].FullName;

    BitmapImage img = new BitmapImage();
    img.SetSource(new FileStream(randpic, FileMode.Open));

    MyImage.Source = img;


}

Version Information

Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

Platforms

Windows Phone

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

See Also

Reference

System.IO Namespace