Question

Is it possible to extend File Class? I would like to add new GetFileSize Method to File Class and use it like this

string s = File.GetFileSize("c:\MyFile.txt");

Implementation

public static string GetFileSize(string fileName)
{

    FileInfo fi = new FileInfo(fileName);
    long Bytes = fi.Length;

    if (Bytes >= 1073741824)
    {
        Decimal size = Decimal.Divide(Bytes, 1073741824);
        return String.Format("{0:##.##} GB", size);
    }
    else if (Bytes >= 1048576)
    {
        Decimal size = Decimal.Divide(Bytes, 1048576);
        return String.Format("{0:##.##} MB", size);
    }
    else if (Bytes >= 1024)
    {
        Decimal size = Decimal.Divide(Bytes, 1024);
        return String.Format("{0:##.##} KB", size);
    }
    else if (Bytes > 0 & Bytes < 1024)
    {
        Decimal size = Bytes;
        return String.Format("{0:##.##} Bytes", size);
    }
    else
    {
        return "0 Bytes";
    }
}

I have tried to use Extension Methods to add the method to File Class but compiler give error “‘System.IO.File’: static types cannot be used as parameters”

Answer 1

No, but you can just create your own static class and put your methods there. Given that you are basically producing a summary string for your user interface, I wouldn’t think that it would belong within the File class anyway (even if you could put it there – which you can’t).