C# FileInfo Class

The FileInfo class in C# is part of the System.IO namespace and provides methods and properties for working with files. It represents a file on disk and allows you to perform various operations such as retrieving file information, manipulating the file, and accessing its contents.

Here are some commonly used properties and methods of the FileInfo class:

Properties:

• FullName: Gets the full path of the file, including the file name.
• Name: Gets just the file name.
• Directory: Gets an instance of the DirectoryInfo class representing the directory that contains the file.
• Exists: Indicates whether the file exists.

Methods:

• Create: Creates a new file at the specified path.
• Delete: Deletes the file.
• CopyTo: Copies the file to a new location.
• MoveTo: Moves the file to a new location.
• Open: Opens the file with the specified FileMode (such as Open, Create, Append, etc.), FileAccess (such as Read, Write, ReadWrite, etc.), and FileShare parameters.
• ReadAllText: Reads the contents of the file and returns it as a string.
• WriteAllText: Writes the specified string to the file, replacing the file contents if it already exists.

Here’s an example that demonstrates some basic usage of the FileInfo class:

using System;
using System.IO;

class Program
{
    static void Main()
    {
        string filePath = @"C:\path\to\file.txt";

        FileInfo fileInfo = new FileInfo(filePath);

        if (fileInfo.Exists)
        {
            Console.WriteLine($"File name: {fileInfo.Name}");
            Console.WriteLine($"Directory: {fileInfo.Directory}");
            Console.WriteLine($"File size: {fileInfo.Length} bytes");
            Console.WriteLine($"Last modified: {fileInfo.LastWriteTime}");
        }
        else
        {
            Console.WriteLine("File does not exist.");
        }
    }
}

In this example, we create a FileInfo object by passing the path to a file. We then check if the file exists and print some information if it does. Otherwise, we display a message indicating that the file does not exist.

Remember to include the System.IO namespace in your code to use the FileInfo class.

C# FileInfo Constructors:

The FileInfo class in C# provides several constructors that allow you to create instances of the class. Here are the different constructors available for the FileInfo class:

1. FileInfo(string path): Initializes a new instance of the FileInfo class, given the path to the file.

string filePath = @"C:\path\to\file.txt";
FileInfo fileInfo = new FileInfo(filePath);

2. FileInfo(Uri uri): Initializes a new instance of the FileInfo class, given a Uri object representing the file path.

Uri fileUri = new Uri("file:///C:/path/to/file.txt");
FileInfo fileInfo = new FileInfo(fileUri);

Note: This constructor is available starting from .NET Framework 4.6.1 and .NET Standard 2.0.

It’s worth noting that when using the FileInfo constructor, the file path should be an absolute path, including the file name and extension. Relative paths can be resolved using Path.Combine() or by specifying the relative path from the current directory.

Here’s an example demonstrating the usage of the FileInfo constructors:

using System;
using System.IO;

class Program
{
    static void Main()
    {
        // Using string path
        string filePath = @"C:\path\to\file.txt";
        FileInfo fileInfo1 = new FileInfo(filePath);

        // Using Uri
        Uri fileUri = new Uri("file:///C:/path/to/file.txt");
        FileInfo fileInfo2 = new FileInfo(fileUri);

        Console.WriteLine($"File 1: {fileInfo1.FullName}");
        Console.WriteLine($"File 2: {fileInfo2.FullName}");
    }
}

In this example, we create two FileInfo objects: one using a string path and the other using a Uri. We then display the full names of both files to confirm that the instances were created correctly.

Remember to include the System.IO namespace in your code to use the FileInfo class and the necessary constructors.

C# FileInfo Example: Creating a File

Certainly! Here’s an example that demonstrates how to use the FileInfo class to create a new file:

using System;
using System.IO;

class Program
{
    static void Main()
    {
        string filePath = @"C:\path\to\newfile.txt";
        
        // Create a FileInfo object for the new file
        FileInfo fileInfo = new FileInfo(filePath);
        
        // Check if the file already exists
        if (!fileInfo.Exists)
        {
            // Create the file using the Create method
            using (FileStream fileStream = fileInfo.Create())
            {
                // Perform any operations on the file if needed
                // For example, write some content to the file
                string content = "This is the content of the new file.";
                byte[] bytes = System.Text.Encoding.UTF8.GetBytes(content);
                fileStream.Write(bytes, 0, bytes.Length);
            }
            
            Console.WriteLine("File created successfully.");
        }
        else
        {
            Console.WriteLine("File already exists.");
        }
    }
}

In this example, we specify the desired file path in the filePath variable. Then, we create a FileInfo object using that path. We check if the file already exists using the Exists property of the FileInfo object.

If the file does not exist, we use the Create method of the FileInfo object to create a new file. We wrap the creation process in a using statement to ensure that the file stream is properly closed after use.

Inside the using block, you can perform any operations you need on the file. In this example, we write some content to the file by converting it to bytes using UTF-8 encoding.

Finally, appropriate messages are displayed based on whether the file was created successfully or if it already exists.

Remember to include the System.IO namespace in your code to use the FileInfo class and related types. Also, make sure you have the necessary permissions to create files in the specified directory.

C# FileInfo Example: writing to the file

Certainly! Here’s an example that demonstrates how to use the FileInfo class to write content to a file:

using System;
using System.IO;

class Program
{
    static void Main()
    {
        string filePath = @"C:\path\to\file.txt";
        
        // Create a FileInfo object for the file
        FileInfo fileInfo = new FileInfo(filePath);
        
        // Check if the file exists
        if (fileInfo.Exists)
        {
            // Open the file in write mode
            using (StreamWriter writer = fileInfo.CreateText())
            {
                // Write content to the file
                writer.WriteLine("This is line 1.");
                writer.WriteLine("This is line 2.");
                writer.WriteLine("This is line 3.");
            }
            
            Console.WriteLine("Content written to the file successfully.");
        }
        else
        {
            Console.WriteLine("File does not exist.");
        }
    }
}

In this example, we specify the path of the file we want to write to in the filePath variable. We create a FileInfo object using that path and check if the file exists using the Exists property.

If the file exists, we open the file in write mode using the CreateText method of the FileInfo object. We wrap the writing process in a using statement to ensure that the StreamWriter is properly closed after use.

Inside the using block, you can use the WriteLine method of the StreamWriter to write content to the file. Each call to WriteLine appends a new line of text to the file.

Finally, appropriate messages are displayed based on whether the file exists and if the content was written successfully.

Remember to include the System.IO namespace in your code to use the FileInfo class and related types. Also, make sure you have the necessary permissions to write to the specified file.

C# FileInfo Example: Reading text from the file

Certainly! Here’s an example that demonstrates how to use the FileInfo class to read text from a file:

using System;
using System.IO;

class Program
{
    static void Main()
    {
        string filePath = @"C:\path\to\file.txt";

        // Create a FileInfo object for the file
        FileInfo fileInfo = new FileInfo(filePath);

        // Check if the file exists
        if (fileInfo.Exists)
        {
            // Read the text content of the file
            string fileContent = File.ReadAllText(filePath);

            // Display the content
            Console.WriteLine("File content:");
            Console.WriteLine(fileContent);
        }
        else
        {
            Console.WriteLine("File does not exist.");
        }
    }
}

In this example, we specify the path of the file we want to read from in the filePath variable. We create a FileInfo object using that path and check if the file exists using the Exists property.

If the file exists, we use the File.ReadAllText method to read the entire content of the file into a string. The ReadAllText method reads the file and automatically closes it when finished.

Finally, if the file exists, we display the content of the file using the Console.WriteLine method.

Remember to include the System.IO namespace in your code to use the FileInfo class and related types. Also, make sure you have the necessary permissions to read the specified file.