StreamWriter Constructor (String, Boolean)
Assembly: mscorlib (in mscorlib.dll)
public StreamWriter ( String path, boolean append )
public function StreamWriter ( path : String, append : boolean )
Parameters
- path
The complete file path to write to.
- append
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.
| Exception type | Condition |
|---|---|
| Access is denied. | |
| path is empty. -or- path contains the name of a system device (com1, com2, and so on). | |
| path is a null reference (Nothing in Visual Basic). | |
| The specified path is invalid, such as being on 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. |
This constructor creates a StreamWriter with UTF-8 encoding without a Byte-Order Mark (BOM), so its GetPreamble method returns an empty byte array. For additional information, see Encoding.
The path parameter can be a file name, including a file on a Universal Naming Convention (UNC) share.
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 an example of using this method, see the Example section. The following table lists examples of other typical or related I/O tasks.
| To do this... | See the example in this topic... |
|---|---|
| Create a text file. | |
| Write to a text file. | |
| Read from a text file. | |
| Append text to a file. | |
| Get the size of a file. | |
| Get the attributes of a file. | |
| Set the attributes of a file. | |
| Determine if a file exists. | |
| Read from a binary file. | |
| Write to a binary file. |
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(); }
public void CreateTextFile(String fileName, String textToAdd)
{
String logFile = DateTime.get_Now().ToShortDateString().
Replace("/", "-").Replace("\\", "-") + ".log";
FileStream fs = new FileStream(fileName, FileMode.CreateNew,
FileAccess.Write, FileShare.None);
StreamWriter swFromFile = new StreamWriter(logFile);
swFromFile.Write(textToAdd);
swFromFile.Flush();
swFromFile.Close();
StreamWriter swFromFileStream = new StreamWriter(fs);
swFromFileStream.Write(textToAdd);
swFromFileStream.Flush();
swFromFileStream.Close();
StreamWriter swFromFileStreamDefaultEnc =
new System.IO.StreamWriter(fs,System.Text.Encoding.get_Default());
swFromFileStreamDefaultEnc.Write(textToAdd);
swFromFileStreamDefaultEnc.Flush();
swFromFileStreamDefaultEnc.Close();
StreamWriter swFromFileTrue = new StreamWriter(fileName, true);
swFromFileTrue.Write(textToAdd);
swFromFileTrue.Flush();
swFromFileTrue.Close();
StreamWriter swFromFileTrueUTF8Buffer = new StreamWriter(fileName,
true, System.Text.Encoding.get_UTF8(), 512);
swFromFileTrueUTF8Buffer.Write(textToAdd);
swFromFileTrueUTF8Buffer.Flush();
swFromFileTrueUTF8Buffer.Close();
StreamWriter swFromFileTrueUTF8 = new StreamWriter(fileName,
true, System.Text.Encoding.get_UTF8());
swFromFileTrueUTF8.Write(textToAdd);
swFromFileTrueUTF8.Flush();
swFromFileTrueUTF8.Close();
StreamWriter swFromFileStreamUTF8Buffer = new StreamWriter(fs,
System.Text.Encoding.get_UTF8(), 512);
swFromFileStreamUTF8Buffer.Write(textToAdd);
swFromFileStreamUTF8Buffer.Flush();
swFromFileStreamUTF8Buffer.Close();
} //CreateTextFile
- FileIOPermission for reading and writing files. Associated enumeration: FileIOPermissionAccess.Read, FileIOPermissionAccess.Write
Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.
Caution