csharp 方法和参数第4条

Posted 2021-05-12

        public class MessageOption
        {
            internal string FromEmailAddress { get; set; }
            internal string MessageSubject { get; set; }
            internal List<string> ToEmailAddresses { get; set; }
            internal string MessageContent { get; set; }

            public MessageOption From(string value)
            {
                FromEmailAddress = value;
                return this;
            }

            public MessageOption Subject(string value)
            {
                MessageSubject = value;
                return this;
            }

            public MessageOption Content(string value)
            {
                MessageContent = value;
                return this;
            }

            public MessageOption AddTo(string emailAddress)
            {
                if (ToEmailAddresses == null)
                    ToEmailAddresses = new List<string>();

                ToEmailAddresses.Add(emailAddress);
                return this;
            }
        }
        public void SendEmail(Action<MessageOption> options)
        {
            var messageOption = new MessageOption();
            options(messageOption);

            //For simplicity implementation is observed.
        }

        //Usage
        public void Test2()
        {
            SendEmail(options => options
                .From("[e-mail]")
                .AddTo("[e-mail]")
                .Subject("Subject of this email")
                .Content("Content of this email")
            );
        }