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StringReader Class

Implements a TextReader that reads from a string.

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

'Declaration
<SerializableAttribute> _
<ComVisibleAttribute(True)> _
Public Class StringReader
	Inherits TextReader
'Usage
Dim instance As StringReader

/** @attribute SerializableAttribute() */ 
/** @attribute ComVisibleAttribute(true) */ 
public class StringReader extends TextReader
SerializableAttribute 
ComVisibleAttribute(true) 
public class StringReader extends TextReader

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.

How to: Write Text to a File

Write to a text file.

How to: Write Text to a File

Read from a text file.

How to: Read Text from a File

Append text to a file.

How to: Open and Append to a Log File

File.AppendText

FileInfo.AppendText

Get the size of a file.

FileInfo.Length

Get the attributes of a file.

File.GetAttributes

Set the attributes of a file.

File.SetAttributes

Determine if a file exists.

File.Exists

Read from a binary file.

How to: Read and Write to a Newly Created Data File

Write to a binary file.

How to: Read and Write to a Newly Created Data File

The following code example demonstrates the creation of a continuous paragraph from a group of double-spaced sentences, and then the conversion of the paragraph back to the original text.

Option Explicit
Option Strict

Imports Microsoft.VisualBasic
Imports System
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

import System.*;
import System.IO.*;

class StringRW
{
    public static void main(String[] args)
    {
        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 aParagraph = "";
        String aLine;
        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 = 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());
    } //main
} //StringRW

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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.

.NET Framework

Supported in: 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

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