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StreamReader Class

Implements a TextReader that reads characters from a byte stream in a particular encoding.

To browse the .NET Framework source code for this type, see the Reference Source.

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

[SerializableAttribute]
[ComVisibleAttribute(true)]
public class StreamReader : TextReader

The StreamReader type exposes the following members.

  NameDescription
Public methodSupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsStreamReader(Stream)Initializes a new instance of the StreamReader class for the specified stream.
Public methodSupported by the XNA FrameworkStreamReader(String)Initializes a new instance of the StreamReader class for the specified file name.
Public methodSupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsStreamReader(Stream, Boolean)Initializes a new instance of the StreamReader class for the specified stream, with the specified byte order mark detection option.
Public methodSupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsStreamReader(Stream, Encoding)Initializes a new instance of the StreamReader class for the specified stream, with the specified character encoding.
Public methodSupported by the XNA FrameworkStreamReader(String, Boolean)Initializes a new instance of the StreamReader class for the specified file name, with the specified byte order mark detection option.
Public methodSupported by the XNA FrameworkStreamReader(String, Encoding)Initializes a new instance of the StreamReader class for the specified file name, with the specified character encoding.
Public methodSupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsStreamReader(Stream, Encoding, Boolean)Initializes a new instance of the StreamReader class for the specified stream, with the specified character encoding and byte order mark detection option.
Public methodSupported by the XNA FrameworkStreamReader(String, Encoding, Boolean)Initializes a new instance of the StreamReader class for the specified file name, with the specified character encoding and byte order mark detection option.
Public methodSupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsStreamReader(Stream, Encoding, Boolean, Int32)Initializes a new instance of the StreamReader class for the specified stream, with the specified character encoding, byte order mark detection option, and buffer size.
Public methodSupported by the XNA FrameworkStreamReader(String, Encoding, Boolean, Int32)Initializes a new instance of the StreamReader class for the specified file name, with the specified character encoding, byte order mark detection option, and buffer size.
Public methodSupported in .NET for Windows Store appsStreamReader(Stream, Encoding, Boolean, Int32, Boolean)Initializes a new instance of the StreamReader class for the specified stream based on the specified character encoding, byte order mark detection option, and buffer size, and optionally leaves the stream open.
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  NameDescription
Public propertySupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsBaseStreamReturns the underlying stream.
Public propertySupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsCurrentEncodingGets the current character encoding that the current StreamReader object is using.
Public propertySupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsEndOfStreamGets a value that indicates whether the current stream position is at the end of the stream.
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  NameDescription
Public methodSupported by the XNA FrameworkCloseCloses the StreamReader object and the underlying stream, and releases any system resources associated with the reader. (Overrides TextReader.Close().)
Public methodCreateObjRefCreates an object that contains all the relevant information required to generate a proxy used to communicate with a remote object. (Inherited from MarshalByRefObject.)
Public methodSupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsDiscardBufferedDataClears the internal buffer.
Public methodSupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsDispose()Releases all resources used by the TextReader object. (Inherited from TextReader.)
Protected methodSupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsDispose(Boolean)Closes the underlying stream, releases the unmanaged resources used by the StreamReader, and optionally releases the managed resources. (Overrides TextReader.Dispose(Boolean).)
Public methodSupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsEquals(Object)Determines whether the specified object is equal to the current object. (Inherited from Object.)
Protected methodSupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodSupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsGetHashCodeServes as the default hash function. (Inherited from Object.)
Public methodGetLifetimeServiceRetrieves the current lifetime service object that controls the lifetime policy for this instance. (Inherited from MarshalByRefObject.)
Public methodSupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsGetTypeGets the Type of the current instance. (Inherited from Object.)
Public methodInitializeLifetimeServiceObtains a lifetime service object to control the lifetime policy for this instance. (Inherited from MarshalByRefObject.)
Protected methodSupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsMemberwiseClone()Creates a shallow copy of the current Object. (Inherited from Object.)
Protected methodMemberwiseClone(Boolean)Creates a shallow copy of the current MarshalByRefObject object. (Inherited from MarshalByRefObject.)
Public methodSupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsPeekReturns the next available character but does not consume it. (Overrides TextReader.Peek().)
Public methodSupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsRead()Reads the next character from the input stream and advances the character position by one character. (Overrides TextReader.Read().)
Public methodSupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsRead(Char[], Int32, Int32)Reads a specified maximum of characters from the current stream into a buffer, beginning at the specified index. (Overrides TextReader.Read(Char[], Int32, Int32).)
Public methodSupported in .NET for Windows Store appsReadAsyncReads a specified maximum number of characters from the current stream asynchronously and writes the data to a buffer, beginning at the specified index. (Overrides TextReader.ReadAsync(Char[], Int32, Int32).)
Public methodSupported by the XNA FrameworkSupported by Portable Class LibraryReadBlockReads a specified maximum number of characters from the current stream and writes the data to a buffer, beginning at the specified index. (Overrides TextReader.ReadBlock(Char[], Int32, Int32).)

In .NET Framework Client Profile 4, this member is inherited from TextReader.ReadBlock(Char[], Int32, Int32).


In XNA Framework 3.0, this member is inherited from TextReader.ReadBlock(Char[], Int32, Int32).


In Portable Class Library Portable Class Library, this member is inherited from TextReader.ReadBlock(Char[], Int32, Int32).
Public methodSupported in .NET for Windows Store appsReadBlockAsyncReads a specified maximum number of characters from the current stream asynchronously and writes the data to a buffer, beginning at the specified index. (Overrides TextReader.ReadBlockAsync(Char[], Int32, Int32).)
Public methodSupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsReadLineReads a line of characters from the current stream and returns the data as a string. (Overrides TextReader.ReadLine().)
Public methodSupported in .NET for Windows Store appsReadLineAsyncReads a line of characters asynchronously from the current stream and returns the data as a string. (Overrides TextReader.ReadLineAsync().)
Public methodSupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsReadToEndReads all characters from the current position to the end of the stream. (Overrides TextReader.ReadToEnd().)
Public methodSupported in .NET for Windows Store appsReadToEndAsyncReads all characters from the current position to the end of the stream asynchronously and returns them as one string. (Overrides TextReader.ReadToEndAsync().)
Public methodSupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsToStringReturns a string that represents the current object. (Inherited from Object.)
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  NameDescription
Public fieldStatic memberSupported by the XNA FrameworkSupported by Portable Class LibrarySupported in .NET for Windows Store appsNullA StreamReader object around an empty stream.
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NoteNote

To view the .NET Framework source code for this type, see the Reference Source. You can browse through the source code online, download the reference for offline viewing, and step through the sources (including patches and updates) during debugging; see instructions.

StreamReader is designed for character input in a particular encoding, whereas the Stream class is designed for byte input and output. Use StreamReader for reading lines of information from a standard text file.

Important noteImportant

This type implements the IDisposable interface. When you have finished using the type, you should dispose of it either directly or indirectly. To dispose of the type directly, call its Dispose method in a try/catch block. To dispose of it indirectly, use a language construct such as using (in C#) or Using (in Visual Basic). For more information, see the “Using an Object that Implements IDisposable” section in the IDisposable interface topic.

StreamReader defaults to UTF-8 encoding unless specified otherwise, instead of defaulting to the ANSI code page for the current system. UTF-8 handles Unicode characters correctly and provides consistent results on localized versions of the operating system. If you get the current character encoding using the CurrentEncoding property, the value is not reliable until after the first Read method, since encoding auto detection is not done until the first call to a Read method.

By default, a StreamReader is not thread safe. See TextReader.Synchronized for a thread-safe wrapper.

The Read(Char[], Int32, Int32) and Write(Char[], Int32, Int32) method overloads read and write the number of characters specified by the count parameter. These are to be distinguished from BufferedStream.Read and BufferedStream.Write, which read and write the number of bytes specified by the count parameter. Use the BufferedStream methods only for reading and writing an integral number of byte array elements.

NoteNote

When reading from a Stream, it is more efficient to use a buffer that is the same size as the internal buffer of the stream.

For a list of common I/O tasks, see Common I/O Tasks.

The following example uses an instance of StreamReader to read text from a file. The constructor used in this example is not supported for use in Windows Store Apps.

using System;
using System.IO;

class Test 
{
    public static void Main() 
    {
        try 
        {
            // Create an instance of StreamReader to read from a file. 
            // The using statement also closes the StreamReader. 
            using (StreamReader sr = new StreamReader("TestFile.txt")) 
            {
                string line;
                // Read and display lines from the file until the end of  
                // the file is reached. 
                while ((line = sr.ReadLine()) != null) 
                {
                    Console.WriteLine(line);
                }
            }
        }
        catch (Exception e) 
        {
            // Let the user know what went wrong.
            Console.WriteLine("The file could not be read:");
            Console.WriteLine(e.Message);
        }
    }
}

.NET Framework

Supported in: 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Store apps

Supported in: Windows 8

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone Silverlight 8.1, Windows Phone Silverlight 8

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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