楼主您好，对于des加解密，不管什么语言，结果都是一样的哦，我曾经和Android的兄弟一起测试过没问题的，您是不是方法没找对，这边给您贴出一个解密方法你试一下吧
//默认密钥向量
private static byte[] Keys = { 0x69, 0x54, 0x73, 0x27, 0x67, 126, 126, 126 };
///
/// DES解密字符串
///
/// 待解密的字符串
/// 解密密钥,要求为8位,和加密密钥相同
/// 解密成功返回解密后的字符串，失败返源串
public static string DecryptDES(string decryptString, string decryptKey)
{
try
{
byte[] rgbKey = Encoding.UTF8.GetBytes(decryptKey);
byte[] rgbIV = Keys;
byte[] inputByteArray = Convert.FromBase64String(decryptString);
DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider();
MemoryStream mStream = new MemoryStream();
CryptoStream cStream = new CryptoStream(mStream, DCSP.CreateDecryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
cStream.Write(inputByteArray, 0, inputByteArray.Length);
cStream.FlushFinalBlock();
return Encoding.UTF8.GetString(mStream.ToArray());
}
catch
{
return decryptString;
}
}