Create Image Thumb Name

if file name contains in path, no problem.


 String CreateThumbName(String fullPath)

        {
            //get file name
            var onlyFilename = System.IO.Path.GetFileNameWithoutExtension(fullPath);
            //name with extension
            var nameWithExt = System.IO.Path.GetFileName(fullPath);
            //just extension
            var ext = System.IO.Path.GetExtension(fullPath);
            //create thumb name
            var thumbName = String.Format("{0}_thumb{1}", onlyFilename, ext);
            //replace file name with thumb name
            var result = fullPath.Replace(nameWithExt, thumbName);
           
            //return result
            return result;
        }

Sample

var fullPath = "c:\windows\MyFolder\my.jpg"
var result = CreateThumbName(fullPath);

Console.WriteLine(result);

Output

c:\windows\MyFolder\my_thumb.jpg