FileInfo class in C#

FileInfo is a class of System.IO namespace and it is useful to perform file operations such as create, read, delete, rename, moving, opening and appending to files.

The FileInfo class will provide the same functionality as File class to manipulate the files but if we are performing multiple operations on the single file, then it’s more efficient to use FileInfo class methods instead of File class methods.

FileInfo class is having a different type of properties and methods to perform operations on files.

FileInfo Properties

The following are the different type of properties which are provided by the FileInfo class to retrieve the information about files.

 

Property	Description
Directory	This property will return an instance of the parent directory of a file.
DirectoryName	It is useful to retrieve the full path of the parent directory of the file.
Exists	This property will return a value that indicates whether the file exists or not.
IsReadOnly	This property is useful to get or set a value that determines whether the current file can be modified or not.
Length	This property will return the size of the current file in bytes.
Name	It is useful to get the name of the file.
Extension	This will return an extension part of the file.
CreationTime	It is useful to get or set the creation time of the current file or directory.
LastAccessTime	It is useful to get or set the last access time of the current file or directory.
LastWriteTime	It is useful to get or set the time when the current file or directory was last written to.

FileInfo Methods

The table below shows the different type of methods which are provided by FileInfo class to perform a different type of operations on files.

Method	Description
Create	This method will create a file.
CopyTo(String)	This method will copies an existing file to a new file but it won't allow overwriting an existing file.
CopyTo(String, Boolean)	This method will copies an existing file to a new file and it will allow overwriting an existing file.
CreateText	It creates a StreamWriter that writes a new text file.
AppendText	It creates a StreamWriter that appends a text to the file.
Encrypt	This method is useful to encrypt a file so that only the account which is used to encrypt the file can decrypt it.
Decrypt	This method is useful to decrypt a file that is encrypted by the current account using the encrypt method.
Delete	This method will delete the file permanently.
Open	It opens a file in the specified mode.
OpenRead	It creates a read-only file stream.
OpenWrite	It creates a write-only file stream.
OpenText	It creates a stream reader that reads from an existing text file.
Replace	This will replace the contents of the specified file with the file described by the current fileinfo object.
ToString	This will return the path as a string.

 

Let’s now see how to use FileInfo class in C# to create, delete, read, move and open operations on file with examples.

 

Using FileInfo Class to Create File in C#

The below code shows the example of creating and writing text to the file using the FileInfo class in C#.

 

using System.IO;

namespace CSharpnaijaTutorial

{

    class Program

    {

        static void Main(string[] args)

        {

            string fpath = @"D:\Test.txt";

            // Check file if exists

            if (File.Exists(fpath))

            {

                File.Delete(fpath);

            }

            // Create the file

            FileInfo fi = new FileInfo(fpath);

            //fi.Create();

            // Create and write data to file

            using (StreamWriter sw = fi.CreateText())

            {

                sw.WriteLine("Hi");

                sw.WriteLine("\r\nWelcome to Csharpnaija");

                sw.WriteLine("\r\nFileInfo Example");

            }

        }

    }

}

If we observe the above example carefully, we imported a System.IO namespace in our example to access File, FileInfo & StreamWriter objects to delete, create and write a text to file.

Using FileInfo Class to Read File

In the first example above, we learned how to use the FileInfo class to create and write a text to file. Now, we will learn how to use the FileInfo class to read text from a file.

 

using System;

using System.IO;

namespace CsharpnaijaTutorial

{

    class Program

    {

        static void Main(string[] args)

        {

            var fpath = @"D:\Test.txt";

            // Check if file exists

            if (File.Exists(fpath))

            {

                FileInfo fi = new FileInfo(fpath);

                // open the file to read text

                using (StreamReader sr = fi.OpenText())

                {

                    string txt;

                    // Read the data from file, until the end of file is reached

                    while ((txt = sr.ReadLine()) != null)

                    {

                        Console.WriteLine(txt);

                    }

                }

            }

            Console.ReadLine();

        }

    }

}

 

If we observe the above example carefully, we imported a System.IO namespace in our example to access FileInfo & StreamReader object to open and read text from the given file.

We will be looking at the TextReader and TextWriter in the next post where we will use the derived classes of the TextReader and TextWriter classes to write and read files.

 

Thank you

 

References

1.     Tutlane

2.     MicrosoftDocumentation