Question

I’ve recently written a small program to rename a bunch of files located in 6 directories. The program loops through each directory from a list and then renames each file in that directory using the File.Move method. The files are renamed to cart_buttons_1.png with the 1 incrementing by 1 each time.

public static int RenameFiles(DirectoryInfo d, StreamWriter sqlStreamWriter, 
                                       int incrementer, int category, int size)
{
    FileInfo[] files = d.GetFiles("*.png");

    foreach (FileInfo fileInfo in files)
    {
        File.Move(fileInfo.FullName, d.FullName + "cart_button_" + incrementer + ".png" );
        incrementer++;
    }

    return incrementer;
}

The problem I’m encountering is when I run the program more than once it runs fine up until it hits the folder containing the 100th record. The d.Getfiles method retrieves all the files with the 100s first, causing and IOException, because the file which it is trying to rename already exists in the folder. The workaround I’ve found for this is just to select all the records with 100 in the filename and renaming them all to ‘z’ or something so that it just batches them all together. Any thoughts or ideas on how to fix this. Possibly some way to sort the GetFiles to look at the others first.

Answer 1

Using LINQ:

var sorted = files.OrderBy(fi => fi.FullName).ToArray();

Note that the above will sort by the textual values, so you may want to change that to order by the numeric value:

files.OrderBy(fi => int.Parse(fi.Name.Split(new []{'_','.'})[2]))

The above assumes that splitting by _ and . of a file name will result in an array with the third value being the numeric value.