Rename a file in C#

Question

How do I rename a file using C#?

Answer 1

You can use File.Move to do it.

Answer 2

  public static class ImageRename
    {
        public static void ApplyChanges(string fileUrl,
                                        string temporaryImageName, 
                                        string permanentImageName)
        {               
                var currentFileName = Path.Combine(fileUrl, 
                                                   temporaryImageName);

                if (!File.Exists(currentFileName))
                    throw new FileNotFoundException();

                var extention = Path.GetExtension(temporaryImageName);
                var newFileName = Path.Combine(fileUrl, 
                                            $"{permanentImageName}
                                              {extention}");

                if (File.Exists(newFileName))
                    File.Delete(newFileName);

                File.Move(currentFileName, newFileName);               
        }
    }

Answer 3

When C# doesn't have some feature, I use C++ or C:

public partial class Program
{
    [DllImport("msvcrt", CallingConvention = CallingConvention.Cdecl, SetLastError = true)]
    public static extern int rename(
            [MarshalAs(UnmanagedType.LPStr)]
            string oldpath,
            [MarshalAs(UnmanagedType.LPStr)]
            string newpath);

    static void FileRename()
    {
        while (true)
        {
            Console.Clear();
            Console.Write("Enter a folder name: ");
            string dir = Console.ReadLine().Trim('\\') + "\\";
            if (string.IsNullOrWhiteSpace(dir))
                break;
            if (!Directory.Exists(dir))
            {
                Console.WriteLine("{0} does not exist", dir);
                continue;
            }
            string[] files = Directory.GetFiles(dir, "*.mp3");

            for (int i = 0; i < files.Length; i++)
            {
                string oldName = Path.GetFileName(files[i]);
                int pos = oldName.IndexOfAny(new char[] { '0', '1', '2' });
                if (pos == 0)
                    continue;

                string newName = oldName.Substring(pos);
                int res = rename(files[i], dir + newName);
            }
        }
        Console.WriteLine("\n\t\tPress any key to go to main menu\n");
        Console.ReadKey(true);
    }
}

Answer 4

In the File.Move method, this won't overwrite the file if it is already exists. And it will throw an exception.

So we need to check whether the file exists or not.

/* Delete the file if exists, else no exception thrown. */

File.Delete(newFileName); // Delete the existing file if exists
File.Move(oldFileName,newFileName); // Rename the oldFileName into newFileName

Or surround it with a try catch to avoid an exception.

Answer 5

1. First solution

   Avoid System.IO.File.Move solutions posted here (marked answer included). It fails over networks. However, copy/delete pattern works locally and over networks. Follow one of the move solutions, but replace it with Copy instead. Then use File.Delete to delete the original file.

   You can create a Rename method to simplify it.

2. Ease of use

   Use the VB assembly in C#. Add reference to Microsoft.VisualBasic

   Then to rename the file:

   Microsoft.VisualBasic.FileIO.FileSystem.RenameFile(myfile, newName);

   Both are strings. Note that myfile has the full path. newName does not. For example:

   a = "C:\whatever\a.txt";
   b = "b.txt";
   Microsoft.VisualBasic.FileIO.FileSystem.RenameFile(a, b);
   

   The C:\whatever\ folder will now contain b.txt.

Answer 6

You can copy it as a new file and then delete the old one using the System.IO.File class:

if (File.Exists(oldName))
{
    File.Copy(oldName, newName, true);
    File.Delete(oldName);
}