StreamWriter Class (System.IO)

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.NET Framework Class Library
StreamWriter Class

Implements a TextWriter for writing characters to a stream in a particular encoding.

Inheritance Hierarchy

System.Object
  System.MarshalByRefObject
    System.IO.TextWriter
      System.IO.StreamWriter

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

Visual Basic
<SerializableAttribute> _
<ComVisibleAttribute(True)> _
Public Class StreamWriter _
	Inherits TextWriter
C#
[SerializableAttribute]
[ComVisibleAttribute(true)]
public class StreamWriter : TextWriter
Visual C++
[SerializableAttribute]
[ComVisibleAttribute(true)]
public ref class StreamWriter : public TextWriter
F#
[<SerializableAttribute>]
[<ComVisibleAttribute(true)>]
type StreamWriter =  
    class
        inherit TextWriter
    end

The StreamWriter type exposes the following members.

Constructors

  Name Description
Public method Supported by the XNA Framework Supported by Portable Class Library StreamWriter(Stream) Initializes a new instance of the StreamWriter class for the specified stream, using UTF-8 encoding and the default buffer size.
Public method Supported by the XNA Framework StreamWriter(String) Initializes a new instance of the StreamWriter class for the specified file on the specified path, using the default encoding and buffer size.
Public method Supported by the XNA Framework Supported by Portable Class Library StreamWriter(Stream, Encoding) Initializes a new instance of the StreamWriter class for the specified stream, using the specified encoding and the default buffer size.
Public method Supported by the XNA Framework StreamWriter(String, Boolean) Initializes a new instance of the StreamWriter class for the specified file on the specified path, using the default encoding and buffer size. If the file exists, it can be either overwritten or appended to. If the file does not exist, this constructor creates a new file.
Public method Supported by the XNA Framework Supported by Portable Class Library StreamWriter(Stream, Encoding, Int32) Initializes a new instance of the StreamWriter class for the specified stream, using the specified encoding and buffer size.
Public method Supported by the XNA Framework StreamWriter(String, Boolean, Encoding) Initializes a new instance of the StreamWriter class for the specified file on the specified path, using the specified encoding and default buffer size. If the file exists, it can be either overwritten or appended to. If the file does not exist, this constructor creates a new file.
Public method Supported by the XNA Framework StreamWriter(String, Boolean, Encoding, Int32) Initializes a new instance of the StreamWriter class for the specified file on the specified path, using the specified encoding and buffer size. If the file exists, it can be either overwritten or appended to. If the file does not exist, this constructor creates a new file.
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Properties

  Name Description
Public property Supported by the XNA Framework Supported by Portable Class Library AutoFlush Gets or sets a value indicating whether the StreamWriter will flush its buffer to the underlying stream after every call to StreamWriter.Write.
Public property Supported by the XNA Framework Supported by Portable Class Library BaseStream Gets the underlying stream that interfaces with a backing store.
Public property Supported by the XNA Framework Supported by Portable Class Library Encoding Gets the Encoding in which the output is written. (Overrides TextWriter.Encoding.)
Public property Supported by the XNA Framework Supported by Portable Class Library FormatProvider Gets an object that controls formatting. (Inherited from TextWriter.)
Public property Supported by the XNA Framework Supported by Portable Class Library NewLine Gets or sets the line terminator string used by the current TextWriter. (Inherited from TextWriter.)
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Methods

  Name Description
Public method Supported by the XNA Framework Close Closes the current StreamWriter object and the underlying stream. (Overrides TextWriter.Close().)
Public method CreateObjRef Creates an object that contains all the relevant information required to generate a proxy used to communicate with a remote object. (Inherited from MarshalByRefObject.)
Public method Supported by the XNA Framework Supported by Portable Class Library Dispose() Releases all resources used by the TextWriter object. (Inherited from TextWriter.)
Protected method Supported by the XNA Framework Supported by Portable Class Library Dispose(Boolean) Releases the unmanaged resources used by the StreamWriter and optionally releases the managed resources. (Overrides TextWriter.Dispose(Boolean).)
Public method Supported by the XNA Framework Supported by Portable Class Library Equals(Object) Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected method Supported by the XNA Framework Supported by Portable Class Library Finalize Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public method Supported by the XNA Framework Supported by Portable Class Library Flush Clears all buffers for the current writer and causes any buffered data to be written to the underlying stream. (Overrides TextWriter.Flush().)
Public method Supported by the XNA Framework Supported by Portable Class Library GetHashCode Serves as a hash function for a particular type. (Inherited from Object.)
Public method GetLifetimeService Retrieves the current lifetime service object that controls the lifetime policy for this instance. (Inherited from MarshalByRefObject.)
Public method Supported by the XNA Framework Supported by Portable Class Library GetType Gets the Type of the current instance. (Inherited from Object.)
Public method InitializeLifetimeService Obtains a lifetime service object to control the lifetime policy for this instance. (Inherited from MarshalByRefObject.)
Protected method Supported by the XNA Framework Supported by Portable Class Library MemberwiseClone() Creates a shallow copy of the current Object. (Inherited from Object.)
Protected method MemberwiseClone(Boolean) Creates a shallow copy of the current MarshalByRefObject object. (Inherited from MarshalByRefObject.)
Public method Supported by the XNA Framework Supported by Portable Class Library ToString Returns a string that represents the current object. (Inherited from Object.)
Public method Supported by the XNA Framework Supported by Portable Class Library Write(Boolean) Writes the text representation of a Boolean value to the text stream. (Inherited from TextWriter.)
Public method Supported by the XNA Framework Supported by Portable Class Library Write(Char) Writes a character to the stream. (Overrides TextWriter.Write(Char).)
Public method Supported by the XNA Framework Supported by Portable Class Library Write(Char[]) Writes a character array to the stream. (Overrides TextWriter.Write(Char[]).)
Public method Supported by the XNA Framework Supported by Portable Class Library Write(Decimal) Writes the text representation of a decimal value to the text stream. (Inherited from TextWriter.)
Public method Supported by the XNA Framework Supported by Portable Class Library Write(Double) Writes the text representation of an 8-byte floating-point value to the text stream. (Inherited from TextWriter.)
Public method Supported by the XNA Framework Supported by Portable Class Library Write(Int32) Writes the text representation of a 4-byte signed integer to the text stream. (Inherited from TextWriter.)
Public method Supported by the XNA Framework Supported by Portable Class Library Write(Int64) Writes the text representation of an 8-byte signed integer to the text stream. (Inherited from TextWriter.)
Public method Supported by the XNA Framework Supported by Portable Class Library Write(Object) Writes the text representation of an object to the text stream by calling ToString on that object. (Inherited from TextWriter.)
Public method Supported by the XNA Framework Supported by Portable Class Library Write(Single) Writes the text representation of a 4-byte floating-point value to the text stream. (Inherited from TextWriter.)
Public method Supported by the XNA Framework Supported by Portable Class Library Write(String) Writes a string to the stream. (Overrides TextWriter.Write(String).)
Public method Supported by the XNA Framework Supported by Portable Class Library Write(UInt32) Writes the text representation of a 4-byte unsigned integer to the text stream. (Inherited from TextWriter.)
Public method Supported by the XNA Framework Supported by Portable Class Library Write(UInt64) Writes the text representation of an 8-byte unsigned integer to the text stream. (Inherited from TextWriter.)
Public method Supported by the XNA Framework Write(String, Object) Writes out a formatted string, using the same semantics as String.Format. (Inherited from TextWriter.)
Public method Supported by the XNA Framework Supported by Portable Class Library Write(String, Object[]) Writes out a formatted string, using the same semantics as String.Format. (Inherited from TextWriter.)
Public method Supported by the XNA Framework Supported by Portable Class Library Write(Char[], Int32, Int32) Writes a subarray of characters to the stream. (Overrides TextWriter.Write(Char[], Int32, Int32).)
Public method Supported by the XNA Framework Write(String, Object, Object) Writes out a formatted string, using the same semantics as String.Format. (Inherited from TextWriter.)
Public method Write(String, Object, Object, Object) Writes out a formatted string, using the same semantics as String.Format. (Inherited from TextWriter.)
Public method Supported by the XNA Framework Supported by Portable Class Library WriteLine() Writes a line terminator to the text stream. (Inherited from TextWriter.)
Public method Supported by the XNA Framework Supported by Portable Class Library WriteLine(Boolean) Writes the text representation of a Boolean followed by a line terminator to the text stream. (Inherited from TextWriter.)
Public method Supported by the XNA Framework Supported by Portable Class Library WriteLine(Char) Writes a character followed by a line terminator to the text stream. (Inherited from TextWriter.)
Public method Supported by the XNA Framework Supported by Portable Class Library WriteLine(Char[]) Writes an array of characters followed by a line terminator to the text stream. (Inherited from TextWriter.)
Public method Supported by the XNA Framework Supported by Portable Class Library WriteLine(Decimal) Writes the text representation of a decimal value followed by a line terminator to the text stream. (Inherited from TextWriter.)
Public method Supported by the XNA Framework Supported by Portable Class Library WriteLine(Double) Writes the text representation of a 8-byte floating-point value followed by a line terminator to the text stream. (Inherited from TextWriter.)
Public method Supported by the XNA Framework Supported by Portable Class Library WriteLine(Int32) Writes the text representation of a 4-byte signed integer followed by a line terminator to the text stream. (Inherited from TextWriter.)
Public method Supported by the XNA Framework Supported by Portable Class Library WriteLine(Int64) Writes the text representation of an 8-byte signed integer followed by a line terminator to the text stream. (Inherited from TextWriter.)
Public method Supported by the XNA Framework Supported by Portable Class Library WriteLine(Object) Writes the text representation of an object by calling ToString on this object, followed by a line terminator to the text stream. (Inherited from TextWriter.)
Public method Supported by the XNA Framework Supported by Portable Class Library WriteLine(Single) Writes the text representation of a 4-byte floating-point value followed by a line terminator to the text stream. (Inherited from TextWriter.)
Public method Supported by the XNA Framework Supported by Portable Class Library WriteLine(String) Writes a string followed by a line terminator to the text stream. (Inherited from TextWriter.)
Public method Supported by the XNA Framework Supported by Portable Class Library WriteLine(UInt32) Writes the text representation of a 4-byte unsigned integer followed by a line terminator to the text stream. (Inherited from TextWriter.)
Public method Supported by the XNA Framework Supported by Portable Class Library WriteLine(UInt64) Writes the text representation of an 8-byte unsigned integer followed by a line terminator to the text stream. (Inherited from TextWriter.)
Public method Supported by the XNA Framework WriteLine(String, Object) Writes out a formatted string and a new line, using the same semantics as Format. (Inherited from TextWriter.)
Public method Supported by the XNA Framework Supported by Portable Class Library WriteLine(String, Object[]) Writes out a formatted string and a new line, using the same semantics as Format. (Inherited from TextWriter.)
Public method Supported by the XNA Framework Supported by Portable Class Library WriteLine(Char[], Int32, Int32) Writes a subarray of characters followed by a line terminator to the text stream. (Inherited from TextWriter.)
Public method Supported by the XNA Framework WriteLine(String, Object, Object) Writes out a formatted string and a new line, using the same semantics as Format. (Inherited from TextWriter.)
Public method WriteLine(String, Object, Object, Object) Writes out a formatted string and a new line, using the same semantics as Format. (Inherited from TextWriter.)
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Fields

  Name Description
Protected field Supported by the XNA Framework Supported by Portable Class Library CoreNewLine Stores the new line characters used for this TextWriter. (Inherited from TextWriter.)
Public field Static member Supported by the XNA Framework Supported by Portable Class Library Null Provides a StreamWriter with no backing store that can be written to, but not read from.
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Remarks

StreamWriter is designed for character output in a particular encoding, whereas classes derived from Stream are designed for byte input and output.

StreamWriter defaults to using an instance of UTF8Encoding unless specified otherwise. This instance of UTF8Encoding is constructed without a byte order mark (BOM), so its GetPreamble method returns an empty byte array. To create a StreamWriter using UTF-8 encoding and a BOM, consider using a constructor that specifies encoding, such as StreamWriter(String, Boolean, Encoding).

By default, a StreamWriter is not thread safe. See TextWriter.Synchronized for a thread-safe wrapper.

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

Examples

The following example shows how to use a StreamWriter object to write a file that lists the directories on the C drive, and then uses a StreamReader object to read and display each directory name. A good practice is to use these objects in a using statement so that the unmanaged resources are correctly disposed. The using statement automatically calls Dispose on the object when the code that is using it has completed.

Visual Basic

Imports System.IO
Class Program

    Shared Sub Main()

        ' Get the directories currently on the C drive.
        Dim cDirs As DirectoryInfo() = New DirectoryInfo("c:\").GetDirectories()

        ' Write each directory name to a file.
        Using sw As StreamWriter = New StreamWriter("CDriveDirs.txt")
            For Each Dir As DirectoryInfo In cDirs
                sw.WriteLine(Dir.Name)
            Next
        End Using

        'Read and show each line from the file.
        Dim line As String = ""
        Using sr As StreamReader = New StreamReader("CDriveDirs.txt")
            Do
                line = sr.ReadLine()
                Console.WriteLine(line)
            Loop Until line Is Nothing
        End Using


    End Sub

End Class


C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;

namespace StreamReadWrite
{
    class Program
    {
        static void Main(string[] args)
        {
            // Get the directories currently on the C drive.
            DirectoryInfo[] cDirs = new DirectoryInfo(@"c:\").GetDirectories();

            // Write each directory name to a file.
            using (StreamWriter sw = new StreamWriter("CDriveDirs.txt"))
            {
                foreach (DirectoryInfo dir in cDirs)
                {
                    sw.WriteLine(dir.Name);

                }
            }

            // Read and show each line from the file.
            string line = "";
            using (StreamReader sr = new StreamReader("CDriveDirs.txt"))
            {
                while ((line = sr.ReadLine()) != null)
                {
                    Console.WriteLine(line);
                }
            }
        }
    }
}


Version Information

.NET Framework

Supported in: 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
Platforms

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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

Other Resources