StreamWriter Constructor (String, Boolean, Encoding, Int32)

StreamWriter Constructor (String, Boolean, Encoding, Int32)

[ 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 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.

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

public StreamWriter(
	string path,
	bool append,
	Encoding encoding,
	int bufferSize


Type: System.String
The complete file path to write to.
Type: System.Boolean
Determines whether data is to be appended to the file. If the file exists and append is false, the file is overwritten. If the file exists and append is true, the data is appended to the file. Otherwise, a new file is created.
Type: System.Text.Encoding
The character encoding to use.
Type: System.Int32
The buffer size.


path is an empty string ("").


path contains the name of a system device (com1, com2, etc).


path or encoding is null.


bufferSize is negative.


path includes an incorrect or invalid syntax for file name, directory name, or volume label syntax.


The caller does not have the required permission.


Access is denied.


The specified path is invalid; for example, it might refer to an unmapped drive.


The specified path, file name, or both exceed the system-defined maximum length. For example, on Windows-based platforms, paths must be less than 248 characters, and file names must be less than 260 characters.

Version Notes

Windows Phone

 This member has a SecurityCriticalAttribute attribute. This attribute restricts this member to internal use. Application code that uses this member throws a MethodAccessException.

Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

Windows Phone

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