FileInfo.AppendText Метод

Определение

Создает StreamWriter, который добавляет текст в файл, представленный этим экземпляром FileInfo.Creates a StreamWriter that appends text to the file represented by this instance of the FileInfo.

public:
 System::IO::StreamWriter ^ AppendText();
public System.IO.StreamWriter AppendText ();
member this.AppendText : unit -> System.IO.StreamWriter
Public Function AppendText () As StreamWriter

Возвраты

Новый объект StreamWriter.A new StreamWriter.

Примеры

В следующем примере текст добавляется в файл и считывается из файла.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
using System;
using System.IO;

class Test 
{
    
    public static void Main() 
    {
        FileInfo fi = new FileInfo(@"c:\MyTest.txt");

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

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

        //Open the file to read from.
        using (StreamReader sr = fi.OpenText()) 
        {
            string s = "";
            while ((s = sr.ReadLine()) != null) 
            {
                Console.WriteLine(s);
            }
        }
    }
}
//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

Imports System.IO

Public Class Test

    Public Shared Sub Main()
        Dim fi As FileInfo = New FileInfo("c:\temp\MyTest.txt")
        Dim sw As StreamWriter

        ' This text is added only once to the file.
        If fi.Exists = False Then
            'Create a file to write to.
            sw = fi.CreateText()
            sw.WriteLine("Hello")
            sw.WriteLine("And")
            sw.WriteLine("Welcome")
            sw.Flush()
            sw.Close()
        End If

        ' This text will always be added, making the file longer over time
        ' if it is not deleted.
        sw = fi.AppendText()

        sw.WriteLine("This")
        sw.WriteLine("is Extra")
        sw.WriteLine("Text")
        sw.Flush()
        sw.Close()

        'Open the file to read from.
        Dim sr As StreamReader = fi.OpenText()
        Dim s As String
        Do While sr.Peek() >= 0
            s = sr.ReadLine()
            Console.WriteLine(s)
        Loop
        sr.Close()
    End Sub
End Class
'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

Следующий пример демонстрирует добавление текста в конец файла, а также отображение результата операции добавления в консоль.The following example demonstrates appending text to the end of a file and also displays the result of the append operation to the console. При первом вызове этой подпрограммы файл создается, если он не существует.The first time this routine is called, the file is created if it does not exist. После этого указанный текст добавляется к файлу.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...

}

using System;
using System.IO;

public class AppendTextTest 
{
    public static void Main() 
    {
        FileInfo fi = new 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 = new 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...
Imports System.IO

Public Class AppendTextTest
    Public Shared Sub Main()
        Dim fi As New FileInfo("temp.txt")
        Dim sw As StreamWriter = fi.AppendText()
        sw.WriteLine("Add as many lines as you like...")
        sw.WriteLine("Add another line to the output...")
        sw.Flush()
        sw.Close()
        Dim sr As New StreamReader(fi.OpenRead())
        ' Get the information out of the file and display it.
        ' Remember that the file might have other lines if it already existed.
        While sr.Peek() <> -1
            Console.WriteLine(sr.ReadLine())
        End While
    End Sub
End Class
'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...

Безопасность

FileIOPermission
для чтения и добавления в файлы.for reading and appending to files. Связанные перечисления: Read,AppendAssociated enumerations: Read, Append

Применяется к

Дополнительно