C# 写的RSA加密字符串的函数，就是不能解密，请高手来看看！！！！！！！！！！！

Question

加密函数
 public string Encrypt_RSA(string encryptString, RSAParameters str_Public_Key)
        {
            try
            {
                byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);
                RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
                rsa.ImportParameters(str_Public_Key); //导入公钥        
                byte[] EncryptedData = rsa.Encrypt(inputByteArray, false);
                return Convert.ToBase64String(EncryptedData);
            }
            catch
            {
                return encryptString;
            }
            
        }解密函数
 public string Decrypt_RSA(string decryptString, RSAParameters str_Private_Key)
        { 
            try
            {
                byte[] inputByteArray = Encoding.UTF8.GetBytes(decryptString);
                RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
                rsa.ImportParameters(str_Private_Key);
                byte[] DecryptedData = rsa.Decrypt(inputByteArray, true);
                return Convert.ToBase64String(DecryptedData);
            }
            catch
            {
                return decryptString;
            }
        }程序能正常运行，但是在加密之后却不能解密，请高手指点下！

Answer 1

 try 
            { 
                byte[] inputByteArray = Encoding.UTF8.GetBytes(decryptString); 
                RSACryptoServiceProvider rsa = new RSACryptoServiceProvider(); 
======这一段换上
byte[] inputByteArray = Convert.FromBase64String(decryptString);