C# 0 The Complete Reference

PART I

C h a p t e r   1 4 :  

U s i n g   I / O  

395

PART IPART I

Here, 

str

 is the string that will be read from.

StringWriter

 defines several constructors. Here is the one that we will use:

StringWriter( )

This constructor creates a writer that will put its output into a string. This string (in the form 

of a 

StringBuilder

) is automatically created by 

StringWriter

. You can obtain the contents of 

this string by calling 

ToString( )

.

Here is an example that uses 

StringReader

 and 

StringWriter

:

// Demonstrate StringReader and StringWriter.

using System;

using System.IO;

class StrRdrDemo {

  static void Main() {

    // Create a StringWriter.

    StringWriter strwtr = new StringWriter();

    // Write to StringWriter.

    for(int i=0; i < 10; i++)

      strwtr.WriteLine("This is i: " + i);

    // Create a StringReader.

    StringReader strrdr = new StringReader(strwtr.ToString());

    // Now, read from StringReader.

    string str = strrdr.ReadLine();

    while(str != null) {

      str = strrdr.ReadLine();

      Console.WriteLine(str);

    }

  }

}

The output is shown here:

This is i: 1

This is i: 2

This is i: 3

This is i: 4

This is i: 5

This is i: 6

This is i: 7

This is i: 8

This is i: 9

The program first creates a