How to pass values from the contact form to the email client?

I am using "Xam.Plugins.Messaging" plugin. I want to pass email form values which are written by the user to the email client also.

Here are my codes:

void SendMailButton(object sender, System.EventArgs e)
        {
            var EmailTask = CrossMessaging.Current.EmailMessenger;

            if (EmailTask.CanSendEmail)
            {
                var emailWithHtmlBody = new EmailMessageBuilder()
                    .To("receiver@receiver.com")
                    .Subject("Email Subject")
                    .BodyAsHtml("<b>Name: </b>" + Name.Text)
                    .BodyAsHtml("<b>Email: </b>" + Email.Text)
                    .BodyAsHtml("<b>Phone: </b>" + Phone.Text)
                    .BodyAsHtml("<b>Message: </b>" + Message.Text)
                    .Build();
                EmailTask.SendEmail(emailWithHtmlBody);
            }
        }

But I cannot fetch values dynamically from the form entries.