The input and output of the C# file

The input and output of the C# file

Class C#I/O

System.IO namespaces have a variety of different classes for performing a variety of file operations, such as creating and deleting files, reading or writing files, closing files, and so on.

The following table lists some of System.IO classes commonly used in the namespace:

FileStream class

System.IO FileStream class in the namespace helps to read and write files and close them. This class is derived from the abstract class Stream.

You need to create a FileStream object to create a new file, or open an existing file. The syntax for creating a FileStream object is as follows:

FileStream <object_name> = new FileStream( <file_name>,
<FileMode Enumerator>, <FileAccess Enumerator>, <FileShare Enumerator>);

For example, create a FileStream object F to read a file .txt sample:

FileStream F = new FileStream("sample.txt", FileMode.Open, FileAccess.Read, FileShare.Read);

The following program demonstrates the use of the FileStream class:

using System;
using System.IO;

namespace FileIOApplication
{
    class Program
    {
        static void Main(string[] args)
        {
            FileStream F = new FileStream("test.dat", 
            FileMode.OpenOrCreate, FileAccess.ReadWrite);

            for (int i = 1; i <= 20; i++)
            {
                F.WriteByte((byte)i);
            }
            F.Position = 0;
            for (int i = 0; i <= 20; i++)
            {
                Console.Write(F.ReadByte() + " ");
            }
            F.Close();
            Console.ReadKey();
        }
    }
}

When the above code is compiled and executed, it produces the following results:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 -1

Advanced file operations for C#

The example above demonstrates the simple file operation in C#. However, to take full advantage of System.IO of classes, you need to know the properties and methods commonly used by those classes.

In the following sections, we'll discuss these classes and what they do. Click the link to learn more about each section: