Simple way
int count = 0;
if ((file.Name != ".") && (file.Name != "..") && file.Name.EndsWith(fileextension))
{
Console.WriteLine(file.FullName);
client.Delete(logFilePath);
count += 1;
Console.ReadKey();
}
more complex (needs more work & using ref for LINQ)
var fileCount = client.ListDirectory(dirName).Where((file.Name != ".") && (file.Name != "..") && file.Name.EndsWith(fileextension)).Count();