StreamWriter Constructor (String, 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 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.

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


Public Sub New ( _
    path As String, _
    append As Boolean _
public StreamWriter(
    string path,
    bool append


  • append
    Type: System..::.Boolean
    true to append data to an existing file; false to overwrite an existing file. If the specified file does not exist, a new file is created regardless of the value of this parameter.


Exception Condition

Access is denied.


path is empty.


path contains the name of a system device (com1, com2, and so on).


path is nullNothingnullptra null reference (Nothing in Visual Basic).


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


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


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.


The caller does not have the required permission.


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.

Version Information

Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0


Windows Phone

See Also


StreamWriter Class

StreamWriter Overload

System.IO Namespace