StreamReader Constructor (Stream, Encoding, Boolean)

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

Initializes a new instance of the StreamReader class for the specified stream, using the specified character encoding and byte order mark detection option.

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


Public Sub New ( _
    stream As Stream, _
    encoding As Encoding, _
    detectEncodingFromByteOrderMarks As Boolean _
public StreamReader(
    Stream stream,
    Encoding encoding,
    bool detectEncodingFromByteOrderMarks


  • detectEncodingFromByteOrderMarks
    Type: System..::.Boolean
    true to look for byte order marks at the beginning of the file; otherwise, false.


Exception Condition

stream does not support reading.


stream or encoding is nullNothingnullptra null reference (Nothing in Visual Basic).


This constructor initializes the encoding as specified by the encoding parameter, the BaseStream property using the stream parameter, and the internal buffer to the default size.

The detectEncodingFromByteOrderMarks parameter detects the encoding by looking at the first three bytes of the stream. It automatically recognizes UTF-8, little-endian Unicode, and big-endian Unicode text if the file starts with the appropriate byte order marks. Otherwise, the user-provided encoding is used. See the Encoding..::.GetPreamble method for more information.

The StreamReader object calls Stream..::.Dispose()()() on the provided Stream object when StreamReader..::.Dispose is called.


When you compile a set of characters with a particular cultural setting and retrieve those same characters with a different cultural setting, the characters might not be interpretable, and could cause an exception to be thrown.

Version Information

Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0


Windows Phone

See Also


StreamReader Class

StreamReader Overload

System.IO Namespace