c# - What's the best way to calculate the size of a directory in .NET?

Question

I've written the following routine to manually traverse through a directory and calculate its size in C#/.NET:

protected static float CalculateFolderSize(string folder)
{
    float folderSize = 0.0f;
    try
    {
        //Checks if the path is valid or not
        if (!Directory.Exists(folder))
            return folderSize;
        else
        {
            try
            {
                foreach (string file in Directory.GetFiles(folder))
                {
                    if (File.Exists(file))
                    {
                        FileInfo finfo = new FileInfo(file);
                        folderSize += finfo.Length;
                    }
                }

                foreach (string dir in Directory.GetDirectories(folder))
                    folderSize += CalculateFolderSize(dir);
            }
            catch (NotSupportedException e)
            {
                Console.WriteLine("Unable to calculate folder size: {0}", e.Message);
            }
        }
    }
    catch (UnauthorizedAccessException e)
    {
        Console.WriteLine("Unable to calculate folder size: {0}", e.Message);
    }
    return folderSize;
}

I have an application which is running this routine repeatedly for a large number of folders. I'm wondering if there's a more efficient way to calculate the size of a folder with .NET? I didn't see anything specific in the framework. Should I be using P/Invoke and a Win32 API? What's the most efficient way of calculating the size of a folder in .NET?

Answer 1

No, this looks like the recommended way to calculate directory size, the relevent method included below:

public static long DirSize(DirectoryInfo d) 
{    
    long size = 0;    
    // Add file sizes.
    FileInfo[] fis = d.GetFiles();
    foreach (FileInfo fi in fis) 
    {      
        size += fi.Length;    
    }
    // Add subdirectory sizes.
    DirectoryInfo[] dis = d.GetDirectories();
    foreach (DirectoryInfo di in dis) 
    {
        size += DirSize(di);   
    }
    return size;  
}

You would call with the root as:

Console.WriteLine("The size is {0} bytes.", DirSize(new DirectoryInfo(targetFolder));

...where targetFolder is the folder-size to calculate.