c# - 无法从文本框中传递变量

Question

在线上

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

它不打印 textBox1.Text 的值，但我打印单词“textBox1.Text”。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  ;

采用

string subject = "hello" + textBox1.Text;

Answer 2

textBox1.Text 不是常量表达式。将其值赋值给字符串而不是 const 字符串

string subject = "hello" + textBox1.Text;

Answer 3

安装使用

Subject = subject,
Body = body

我建议你也改变它

Subject = subject.Text,
Body = body.Text

只需将“subject.Text”和“body.Text”更改为您的文本框名称但您必须保留 .Text