c# - 无法从文本框传递变量

Question

在线

const string subject = "hello" + textBox1.Text;

它不打印 textBox1.Text 的值，但我打印了“textBox1.Text”这个词。我该如何解决？

var fromAddress = new MailAddress("samuimark@gmail.com", "samui mail");
var toAddress = new MailAddress("teeramail@gmail.com", "To Name");
const string fromPassword = "t429";
const string subject = "hello" + textBox1.Text  ;
const string body = "you have a mail";

var smtp = new SmtpClient
{
    Host = "smtp.gmail.com",
    Port = 587,
    EnableSsl = true,
    DeliveryMethod = SmtpDeliveryMethod.Network,
    UseDefaultCredentials = false,
    Credentials = new NetworkCredential(fromAddress.Address, fromPassword)
};
using (var message = new MailMessage(fromAddress, toAddress)
{
    Subject = subject,
    Body = body
})
{
    smtp.Send(message);
}

Answer 1

代替

const string subject = "hello" + textBox1.Text  ;

使用

string subject = "hello" + textBox1.Text;