FileInfo::AppendText Method ()

 

Creates a StreamWriter that appends text to the file represented by this instance of the FileInfo.

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

public:
StreamWriter^ AppendText()

Return Value

Type: System.IO::StreamWriter^

A new StreamWriter.

The following example appends text to a file and reads from the file.

using namespace System;
using namespace System::IO;

int main()
{
   FileInfo^ fi = gcnew FileInfo( "c:\\MyTest.txt" );

   // This text is added only once to the file.
   if (  !fi->Exists )
   {
      //Create a file to write to.
      StreamWriter^ sw = fi->CreateText();
      try
      {
         sw->WriteLine( "Hello" );
         sw->WriteLine( "And" );
         sw->WriteLine( "Welcome" );
      }
      finally
      {
         if ( sw )
            delete (IDisposable^)sw;
      }
   }

   // This text will always be added, making the file longer over time
   // if it is not deleted.
   StreamWriter^ sw = fi->AppendText();
   try
   {
      sw->WriteLine( "This" );
      sw->WriteLine( "is Extra" );
      sw->WriteLine( "Text" );
   }
   finally
   {
      if ( sw )
         delete (IDisposable^)sw;
   }

   //Open the file to read from.
   StreamReader^ sr = fi->OpenText();
   try
   {
      String^ s = "";
      while ( s = sr->ReadLine() )
      {
         Console::WriteLine( s );
      }
   }
   finally
   {
      if ( sr )
         delete (IDisposable^)sr;
   }
}
//This code produces output similar to the following; 
//results may vary based on the computer/file structure/etc.:
//
//Hello
//And
//Welcome
//This
//is Extra
//Text
//
//When you run this application a second time, you will see the following output:
//
//Hello
//And
//Welcome
//This
//is Extra
//Text
//This
//is Extra
//Text

The following example demonstrates appending text to the end of a file and also displays the result of the append operation to the console. The first time this routine is called, the file is created if it does not exist. After that, the specified text is appended to the file.

using namespace System;
using namespace System::IO;
int main()
{

   FileInfo^ fi = gcnew FileInfo( "temp.txt" );

   // Create a writer, ready to add entries to the file.
   StreamWriter^ sw = fi->AppendText();
   sw->WriteLine( "Add as many lines as you like..." );
   sw->WriteLine( "Add another line to the output..." );
   sw->Flush();
   sw->Close();

   // Get the information out of the file and display it.
   // Remember that the file might have other lines if it already existed.
   StreamReader^ sr = gcnew StreamReader( fi->OpenRead() );
   while ( sr->Peek() != -1 )
      Console::WriteLine( sr->ReadLine() );
//This code produces output similar to the following;
//results may vary based on the computer/file structure/etc.:
//Add as many lines as you like...
//Add another line to the output...

}

FileIOPermission

for reading and appending to files. Associated enumerations: FileIOPermissionAccess::Read, FileIOPermissionAccess::Append

Universal Windows Platform
Available since 10
.NET Framework
Available since 1.1
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
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