StringWriter Класс

Определение

public ref class StringWriter : System::IO::TextWriter

public class StringWriter : System.IO.TextWriter

[System.Serializable]
public class StringWriter : System.IO.TextWriter

[System.Serializable]
[System.Runtime.InteropServices.ComVisible(true)]
public class StringWriter : System.IO.TextWriter

type StringWriter = class
    inherit TextWriter

[<System.Serializable>]
type StringWriter = class
    inherit TextWriter

[<System.Serializable>]
[<System.Runtime.InteropServices.ComVisible(true)>]
type StringWriter = class
    inherit TextWriter

Public Class StringWriter
Inherits TextWriter

Наследование

Object

TextWriter

StringWriter

Наследование

Object

MarshalByRefObject

TextWriter

StringWriter

Атрибуты

SerializableAttribute ComVisibleAttribute

Примеры

В следующем примере кода показано создание непрерывного абзаца из группы двойных предложений, а затем преобразование абзаца обратно в исходный текст.

using namespace System;
using namespace System::IO;
int main()
{
   String^ textReaderText = "TextReader is the abstract base "
   "class of StreamReader and StringReader, which read "
   "characters from streams and strings, respectively.\n\n"
   "Create an instance of TextReader to open a text file "
   "for reading a specified range of characters, or to "
   "create a reader based on an existing stream.\n\n"
   "You can also use an instance of TextReader to read "
   "text from a custom backing store using the same "
   "APIs you would use for a string or a stream.\n\n";
   Console::WriteLine(  "Original text:\n\n{0}", textReaderText );

   // From textReaderText, create a continuous paragraph 
   // with two spaces between each sentence.
      String^ aLine;
   String^ aParagraph;
   StringReader^ strReader = gcnew StringReader( textReaderText );
   while ( true )
   {
      aLine = strReader->ReadLine();
      if ( aLine != nullptr )
      {
         aParagraph = String::Concat( aParagraph, aLine,  " " );
      }
      else
      {
         aParagraph = String::Concat( aParagraph,  "\n" );
         break;
      }
   }

   Console::WriteLine(  "Modified text:\n\n{0}", aParagraph );
   
   // Re-create textReaderText from aParagraph.
   int intCharacter;
   Char convertedCharacter;
   StringWriter^ strWriter = gcnew StringWriter;
   strReader = gcnew StringReader( aParagraph );
   while ( true )
   {
      intCharacter = strReader->Read();
      
      // Check for the end of the string 
      // before converting to a character.
      if ( intCharacter == -1 )
            break;

      
      convertedCharacter = Convert::ToChar( intCharacter );
      if ( convertedCharacter == '.' )
      {
         strWriter->Write(  ".\n\n" );
         
         // Bypass the spaces between sentences.
         strReader->Read();
         strReader->Read();
      }
      else
      {
         strWriter->Write( convertedCharacter );
      }
   }

   Console::WriteLine(  "\nOriginal text:\n\n{0}", strWriter->ToString() );
}

using System;
using System.IO;

class StringRW
{
    static void Main()
    {
        string textReaderText = "TextReader is the abstract base " +
            "class of StreamReader and StringReader, which read " +
            "characters from streams and strings, respectively.\n\n" +

            "Create an instance of TextReader to open a text file " +
            "for reading a specified range of characters, or to " +
            "create a reader based on an existing stream.\n\n" +

            "You can also use an instance of TextReader to read " +
            "text from a custom backing store using the same " +
            "APIs you would use for a string or a stream.\n\n";

        Console.WriteLine("Original text:\n\n{0}", textReaderText);

        // From textReaderText, create a continuous paragraph
        // with two spaces between each sentence.
        string aLine, aParagraph = null;
        StringReader strReader = new StringReader(textReaderText);
        while(true)
        {
            aLine = strReader.ReadLine();
            if(aLine != null)
            {
                aParagraph = aParagraph + aLine + " ";
            }
            else
            {
                aParagraph = aParagraph + "\n";
                break;
            }
        }
        Console.WriteLine("Modified text:\n\n{0}", aParagraph);

        // Re-create textReaderText from aParagraph.
        int intCharacter;
        char convertedCharacter;
        StringWriter strWriter = new StringWriter();
        strReader = new StringReader(aParagraph);
        while(true)
        {
            intCharacter = strReader.Read();

            // Check for the end of the string
            // before converting to a character.
            if(intCharacter == -1) break;

            convertedCharacter = (char)intCharacter;
            if(convertedCharacter == '.')
            {
                strWriter.Write(".\n\n");

                // Bypass the spaces between sentences.
                strReader.Read();
                strReader.Read();
            }
            else
            {
                strWriter.Write(convertedCharacter);
            }
        }
        Console.WriteLine("\nOriginal text:\n\n{0}",
            strWriter.ToString());
    }
}

Option Explicit
Option Strict

Imports System.IO

Public Class StrReader

    Shared Sub Main()
    
        Dim textReaderText As String = "TextReader is the " & _
            "abstract base class of StreamReader and " & _
            "StringReader, which read characters from streams " & _
            "and strings, respectively." & _
            vbCrLf & vbCrLf & _
            "Create an instance of TextReader to open a text " & _
            "file for reading a specified range of characters, " & _
            "or to create a reader based on an existing stream." & _
            vbCrLf & vbCrLf & _
            "You can also use an instance of TextReader to read " & _
            "text from a custom backing store using the same " & _
            "APIs you would use for a string or a stream." & _
            vbCrLf & vbCrLf

        Console.WriteLine("Original text:" & vbCrLf & vbCrLf & _
            textReaderText)

        ' From textReaderText, create a continuous paragraph 
        ' with two spaces between each sentence.
        Dim aLine, aParagraph As String
        Dim strReader As New StringReader(textReaderText)
        While True
            aLine = strReader.ReadLine()
            If aLine Is Nothing Then
                aParagraph = aParagraph & vbCrLf
                Exit While
            Else
                aParagraph = aParagraph & aLine & " "
            End If
        End While
        Console.WriteLine("Modified text:" & vbCrLf & vbCrLf & _ 
            aParagraph)
    
        ' Re-create textReaderText from aParagraph.
        Dim intCharacter As Integer 
        Dim convertedCharacter As Char 
        Dim strWriter As New StringWriter()
        strReader = New StringReader(aParagraph)
        While True
            intCharacter = strReader.Read()

            ' Check for the end of the string 
            ' before converting to a character.
            If intCharacter = -1 Then
                Exit While
            End If

            convertedCharacter = Convert.ToChar(intCharacter)
            If convertedCharacter = "."C Then
                strWriter.Write("." & vbCrLf & vbCrLf)

                ' Bypass the spaces between sentences.
                strReader.Read()
                strReader.Read()
            Else
                strWriter.Write(convertedCharacter)
            End If
        End While
        Console.WriteLine(vbCrLf & "Original text:" & vbCrLf & _ 
            vbCrLf & strWriter.ToString())

    End Sub
End Class

Комментарии

StringWriter позволяет записывать в строку синхронно или асинхронно. Символ можно написать одновременно с помощью Write(Char) или метода WriteAsync(Char), строки за раз с помощью Write(String) или метода WriteAsync(String). Кроме того, можно написать символ, массив символов или строку, за которой следует терминатор строки асинхронно с одним из методов WriteLineAsync.

В следующей таблице перечислены примеры других типичных или связанных задач ввода-вывода.

Конструкторы

Поля

Свойства

Методы

Явные реализации интерфейса

Методы расширения

Применяется к

См. также раздел

• StringBuilder
• StringReader
• файлов и потоковой ввода-вывода
• Практическое руководство. Чтение текста из файла
• Практическое руководство. Запись текста в файл