public void RenameFile(string filePath, string newName)
{
    FileInfo fileInfo = new FileInfo(filePath);
    fileInfo.MoveTo(fileInfo.Directory.FullName + "\\" + newName);
}

当c#没有某些特性时，我就用c++或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);
    }
}

private static void Rename_File(string FileFullPath, string NewName) // nes name without directory actualy you can simply rename with fileinfo.MoveTo(Fullpathwithnameandextension);
        {
            FileInfo fileInfo = new FileInfo(FileFullPath);
            string DirectoryRoot = Directory.GetParent(FileFullPath).FullName;

            string filecreator = FileFullPath.Substring(DirectoryRoot.Length,FileFullPath.Length-DirectoryRoot.Length);
             
            filecreator = DirectoryRoot + NewName;
            try
            {
                fileInfo.MoveTo(filecreator);
            }
            catch(Exception ex)
            {
                Console.WriteLine(filecreator);
                Console.WriteLine(ex.Message);
                Console.ReadKey();
            }

    enter code here
            // string FileDirectory = Directory.GetDirectoryRoot()

        }

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);
    }
}

public void RenameFile(string filePath, string newName)
{
    FileInfo fileInfo = new FileInfo(filePath);
    fileInfo.MoveTo(fileInfo.Directory.FullName + "\\" + newName);
}

在文件中。方法，这将不会覆盖文件，如果它已经存在。它会抛出一个异常。

所以我们需要检查文件是否存在。

/* 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

或者用try catch将其包围以避免异常。