StreamWriter Constructor (String)
Initializes a new instance of the StreamWriter class for the specified file on the specified path, using the default encoding and buffer size.
Assembly: mscorlib (in mscorlib.dll)
Parameters
- path
- Type: System::String
The complete file path to write to. path can be a file name.
| Exception | Condition |
|---|---|
| UnauthorizedAccessException | Access is denied. |
| ArgumentException | path is an empty string (""). -or- path contains the name of a system device (com1, com2, and so on). |
| ArgumentNullException | path is nullptr. |
| DirectoryNotFoundException | The specified path is invalid, such as being on an unmapped drive. |
| PathTooLongException | 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. |
| IOException | path includes an incorrect or invalid syntax for file name, directory name, or volume label syntax. |
| SecurityException | The caller does not have the required permission. |
This constructor creates a StreamWriter with UTF-8 encoding 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).
The path parameter can be a file name, including a file on a Universal Naming Convention (UNC) share. If the file exists, it is overwritten; otherwise, a new file is created.
The path parameter is not required to be a file stored on disk; it can be any part of a system that supports access using streams.
Caution |
|---|
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. |
For a list of common I/O tasks, see Common I/O Tasks.
The following code example demonstrates the StreamWriter constructors.
void CreateTextFile( String^ fileName, String^ textToAdd ) { String^ logFile = String::Concat( DateTime::Now.ToShortDateString() ->Replace( "/", "-" )->Replace( "\\", "-" ), ".log" ); FileStream^ fs = gcnew FileStream( fileName, FileMode::CreateNew, FileAccess::Write, FileShare::None ); StreamWriter^ swFromFile = gcnew StreamWriter( logFile ); swFromFile->Write( textToAdd ); swFromFile->Flush(); swFromFile->Close(); StreamWriter^ swFromFileStream = gcnew StreamWriter( fs ); swFromFileStream->Write( textToAdd ); swFromFileStream->Flush(); swFromFileStream->Close(); StreamWriter^ swFromFileStreamDefaultEnc = gcnew System::IO::StreamWriter( fs, System::Text::Encoding::Default ); swFromFileStreamDefaultEnc->Write( textToAdd ); swFromFileStreamDefaultEnc->Flush(); swFromFileStreamDefaultEnc->Close(); StreamWriter^ swFromFileTrue = gcnew StreamWriter( fileName,true ); swFromFileTrue->Write( textToAdd ); swFromFileTrue->Flush(); swFromFileTrue->Close(); StreamWriter^ swFromFileTrueUTF8Buffer = gcnew StreamWriter( fileName, true, System::Text::Encoding::UTF8, 512 ); swFromFileTrueUTF8Buffer->Write( textToAdd ); swFromFileTrueUTF8Buffer->Flush(); swFromFileTrueUTF8Buffer->Close(); StreamWriter^ swFromFileTrueUTF8 = gcnew StreamWriter( fileName, true, System::Text::Encoding::UTF8 ); swFromFileTrueUTF8->Write( textToAdd ); swFromFileTrueUTF8->Flush(); swFromFileTrueUTF8->Close(); StreamWriter^ swFromFileStreamUTF8Buffer = gcnew StreamWriter( fs, System::Text::Encoding::UTF8, 512 ); swFromFileStreamUTF8Buffer->Write( textToAdd ); swFromFileStreamUTF8Buffer->Flush(); swFromFileStreamUTF8Buffer->Close(); }
- FileIOPermission
for reading and writing files. Associated enumeration: FileIOPermissionAccess::Read, FileIOPermissionAccess::Write
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.
Caution