/// <summary>
 /// 解码编码为字符串的数据,算法: ((firstByte - 65) 左移 4) + lastByte - 65 => sourceByte
 /// </summary>
 /// <param name="strData">字符串数据</param>
 /// <param name="filePath">要保存的文件名</param>
 /// <returns></returns>
 public static void DecodingFile(string strData, string filePath)
 {
     byte[] buffer = FileStringCodingEx.DecodingString(strData);
     using (FileStream fs = new FileStream(filePath, FileMode.Create, FileAccess.ReadWrite))
     {
         fs.Write(buffer, 0, buffer.Length);
     }
 }