You can clear the special characters using the below customized function as:
private static string GetCleanString (string src)
{
int i = 0;
while (i < src.Length)
{
if (src[i] < 32 || src[i] > 127)
{
int pos = CHAR_REPLACE_SRC.IndexOf(src[i]);
if (pos >= 0)
src = src.Replace(CHAR_REPLACE_SRC[pos], CHAR_REPLACE_DST[pos]);
else
src = src.Remove(i, 1);
}
else
i++;
}
return src.Replace("\"", "").Replace("?", "").Replace(":", "").Replace("&", "_").Replace("\\", "_").Replace("/", "_");
}