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 | |
|---|---|---|
.gif "Public method") |
FileStream(String, FileMode) | Initializes a new instance of the FileStream class with the specified path and creation mode. |
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FileStream(String, FileMode, FileAccess) | Initializes a new instance of the FileStream class with the specified path, creation mode, and read/write permission. |
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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. |
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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 | |
|---|---|---|
.gif "Public property") |
CanRead | Gets a value indicating whether the current stream supports reading. (Overrides Stream..::.CanRead.) |
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CanSeek | Gets a value indicating whether the current stream supports seeking. (Overrides Stream..::.CanSeek.) |
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CanTimeout | Gets a value that determines whether the current stream can time out. (Inherited from Stream.) |
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CanWrite | Gets a value indicating whether the current stream supports writing. (Overrides Stream..::.CanWrite.) |
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Length | Gets the length in bytes of the stream. (Overrides Stream..::.Length.) |
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Name | Gets the name of the file stream that was passed to the constructor. |
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Position | Gets or sets the current position of this stream. (Overrides Stream..::.Position.) |
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ReadTimeout | Gets or sets a value, in miliseconds, that determines how long the stream will attempt to read before timing out. (Inherited from Stream.) |
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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 | |
|---|---|---|
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BeginRead | Begins an asynchronous read. (Overrides Stream..::.BeginRead(array<Byte>[]()[], Int32, Int32, AsyncCallback, Object).) |
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BeginWrite | Begins an asynchronous write. (Overrides Stream..::.BeginWrite(array<Byte>[]()[], Int32, Int32, AsyncCallback, Object).) |
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Close | Closes the current stream and releases any resources (such as sockets and file handles) associated with the current stream. (Inherited from Stream.) |
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CopyTo(Stream) | Reads all the bytes from the current stream and writes them to the destination stream. (Inherited from Stream.) |
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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.) |
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CopyToAsync(Stream) | Asynchronously reads the bytes from the current stream and writes them to another stream. (Inherited from Stream.) |
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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.) |
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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.) |
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Dispose()()() | Releases all resources used by the Stream. (Inherited from Stream.) |
.gif "Protected method") |
Dispose(Boolean) | Releases the unmanaged resources used by the FileStream and optionally releases the managed resources. (Overrides Stream..::.Dispose(Boolean).) |
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EndRead | Waits for the pending asynchronous read to complete. (Overrides Stream..::.EndRead(IAsyncResult).) |
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EndWrite | Ends an asynchronous write, blocking until the I/O operation has completed. (Overrides Stream..::.EndWrite(IAsyncResult).) |
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Equals(Object) | Determines whether the specified Object is equal to the current Object. (Inherited from Object.) |
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Finalize | Ensures that resources are freed and other cleanup operations are performed when the garbage collector reclaims the FileStream. (Overrides Object..::.Finalize()()().) |
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Flush()()() | Clears all buffers for this stream and causes any buffered data to be written to the file system. (Overrides Stream..::.Flush()()().) |
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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. |
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FlushAsync()()() | Asynchronously clears all buffers for this stream and causes any buffered data to be written to the underlying device. (Inherited from Stream.) |
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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.) |
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GetHashCode | Serves as a hash function for a particular type. (Inherited from Object.) |
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GetType | Gets the Type of the current instance. (Inherited from Object.) |
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MemberwiseClone | Creates a shallow copy of the current Object. (Inherited from Object.) |
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Read | Reads a block of bytes from the stream and writes the data in a given buffer. (Overrides Stream..::.Read(array<Byte>[]()[], Int32, Int32).) |
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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.) |
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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.) |
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ReadByte | Reads a byte from the file and advances the read position one byte. (Overrides Stream..::.ReadByte()()().) |
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Seek | Sets the current position of this stream to the given value. (Overrides Stream..::.Seek(Int64, SeekOrigin).) |
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SetLength | Sets the length of this stream to the given value. (Overrides Stream..::.SetLength(Int64).) |
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ToString | Returns a string that represents the current object. (Inherited from Object.) |
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Write | Writes a block of bytes to this stream using data from a buffer. (Overrides Stream..::.Write(array<Byte>[]()[], Int32, Int32).) |
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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.) |
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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.) |
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WriteByte | Writes a byte to the current position in the file stream. (Overrides Stream..::.WriteByte(Byte).) |
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Extension Methods
| Name | Description | |
|---|---|---|
.gif "Public Extension Method") |
AsInputStream | (Defined by WindowsRuntimeStreamExtensions.) |
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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.