TextReader

This reads text characters from a file. It is internally used by many other types in .NET. But you can access it for a general method of reading text content.

A warning

TextReader is used interally by StreamReader. But it is usually better to use StreamReader in your programs—StreamReader has more ease of use.

Example

Here we use the TextReader class. We use the using statement, providing for proper cleanup of the system resources related to the operating system and file system.

using System;
using System.IO;

class Program
{
    static void Main()
    {
        //
        // Read one line with TextReader.
        //
        using (TextReader reader = File.OpenText(@"C:\perl.txt"))
        {
            string line = reader.ReadLine();
            Console.WriteLine(line);
        }
        //
        // Read three text characters with TextReader.
        //
        using (TextReader reader = File.OpenText(@"C:\perl.txt"))
        {
            char[] block = new char[3];
            reader.ReadBlock(block, 0, 3);
            Console.WriteLine(block);
        }
        //
        // Read entire text file with TextReader.
        //
        using (TextReader reader = File.OpenText(@"C:\perl.txt"))
        {
            string text = reader.ReadToEnd();
            Console.WriteLine(text.Length);
        }
        //
        // Peek at first character in file with TextReader.
        //
        using (TextReader reader = File.OpenText(@"C:\perl.txt"))
        {
            char first = (char)reader.Peek();
            Console.WriteLine(first);
        }
    }
}
First line
Fir
18
F

TextWriter

The TextWriter class is an abstract base class. StreamWriter implements additional logic for text encodings, making it a more useful class in many cases.

A summary

We explored the TextReader class. We can use the using statement with a resource acquisition statement, and then read lines, blocks of text, or entire files into strings.