最简单的异或加密解密，特点是加密解密算法相同：下面的可以直接测试。 private void button1_Click(object sender, EventArgs e)        {             byte key = 123;             Text = encryptDecryptStr(textBox1.Text, key);        }        private string encryptDecryptStr(string p, byte key)        {             byte[] bs = Encoding.Default.GetBytes(p);             for (int i = 0; i < bs.Length; i++)             {                 bs[i] = (byte)(bs[i] ^ key);             }             return Encoding.Default.GetString(bs);        }        private void button2_Click(object sender, EventArgs e)        {             byte key = 123;             button2.Text = encryptDecryptStr(Text, key);        }