C# Change the file extension of a file - FileInfo.MoveTo

FileInfo.MoveTo method Usage

The following code change the file extension of a file from ".txt" to ".md".

FileInfo Properties Used:

• fileInfo.Name
• fileInfo.Extension

string desktop = Environment.GetFolderPath(Environment.SpecialFolder.Desktop);
string source_folder = Path.Combine(desktop, "source_folder");
if (Directory.Exists(source_folder))
{
    FileInfo fileInfo = new FileInfo(Path.Combine(source_folder, "abc.txt"));
    string oldName = fileInfo.Name;
    string oldExtension = fileInfo.Extension;
    string newExtension = ".md";
    string newName = fileInfo.Name.Substring(0, oldName.Length - oldExtension.Length) + newExtension;
    fileInfo.MoveTo(Path.Combine(source_folder, newName));
    Console.WriteLine("Files renamed successfully.");
}
else
{
    Console.WriteLine("Some Error.");
}