C# / .NET - get file size

In this article, we're going to have a look at how to get file size in C# / .NET.

Quick solution:

FileInfo file = new System.IO.FileInfo(@"C:\path\to\file.txt");
int fileSize = file.Length;

Look at the below code to see practical usage example:

1. FileInfo class example

In the presented solution FileInfo class was used with Length property that returns file size.

Note: if file was modified after FileInfo object was created Refresh() method should be called on the object to get current file inforamtions.

using System;
using System.IO;

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

		FileInfo info = new FileInfo(path);
		Console.WriteLine("File size: " + info.Length + " bytes");
	}
}

Output:

File size: 46 bytes

2. File.Open method with Length property example

In some cases when we use Length property with specific stream, we need to be sure that the property is implemented - for File.Open method result it is.

Note: this approach is useful when we have opened stream.

using System;
using System.IO;

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

		using (FileStream stream = File.Open(path, FileMode.Open))
		{
			Console.WriteLine("File size: " + stream.Length + " bytes");
		}
	}
}

Output:

File size: 46 bytes

References

1. FileInfo.Length Property - Microsoft Docs