1. warning SYSLIB0021: “DESCryptoServiceProvider”已过时:“Derived cryptographic types are obsolete. Use the Create method on the base type instead.”


var des = new DESCryptoServiceProvider();  修改为：var des = DES.Create();


2. warning SYSLIB0021: MD5CryptoServiceProvider”已过时:“Derived cryptographic types are obsolete. Use the Create method on the base type instead.


MD5 md5 = new MD5CryptoServiceProvider(); 修改为： MD5 md5 = MD5.Create();


3. warning SYSLIB0021: “SHA1Managed”已过时:“Derived cryptographic types are obsolete. Use the Create method on the base type instead.”


var hash = new SHA1Managed(); 替换为： var hash = SHA1.Create();   其他类似： SHA256.Create();  SHA512.Create();


4. “RNGCryptoServiceProvider”已过时:“RNGCryptoServiceProvider is obsolete. To generate a random number, use one of the RandomNumberGenerator static methods instead.”


RandomNumberGenerator.GetInt32(Int32)   RandomNumberGenerator.Create()


5. warning SYSLIB0022: “RijndaelManaged”已过时:“The Rijndael and RijndaelManaged types are obsolete. Use Aes instead.”


var rDel = new RijndaelManaged(); 替换为  var rDel = Aes.Create("AesManaged")