參數'from'不能是空字符串。參數名稱：從

Question

好吧，基本上我的網站上有一個評論表。人們只是在評論框中發表評論，並將評論通過電子郵件發送給我的電子郵件。電子郵件部分工作正常，並通過。但是，當我嘗試清除表單域時出現錯誤。它給我一個錯誤說：

錯誤：參數'從'不能是一個空字符串。 參數名稱：從

所以任何人有任何想法？就像我說的電子郵件部分工作正常，它只是清除場是給我找麻煩

這裏是代碼：

Imports System.Web.Mail 
Imports System.Text 

Partial Class Pages_ContactUs : Inherits System.Web.UI.Page 

Protected Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click 

    Dim body As String = "From: " + YourName.Text + " " + Environment.NewLine + "Email: " + YourEmail.Text + Environment.NewLine + Environment.NewLine + "Message: " + Environment.NewLine + Comments.Text 

    Dim MM As New System.Net.Mail.SmtpClient 
    MM.EnableSsl = True 
    MM.Host = "smtp.gmail.com" 
    Dim cred As New System.Net.NetworkCredential("myEmail@gmail.com", "myPassword") 
    MM.Credentials = cred 
    MM.Send(YourEmail.Text, "myEmail@gmail.com", Subject.Text, body) 
    ClearFields() 
    lblEmail.ForeColor = Drawing.Color.Green 
    lblEmail.Text = "Your message has been sent successfuly" 
    lblEmail.Visible = True 

End Sub 

Protected Sub ClearFields() 
    YourName.Text = "" 
    YourEmail.Text = "" 
    Comments.Text = "" 
    Subject.Text = "" 
End Sub 
End Class 

Answer 1

你必須提供它，只是把它變成你。基本模式：

Using SmtpServer As New SmtpClient() 
    Using mail As New System.Web.Mail.MailMessage() 
    Try 
     SmtpServer.UseDefaultCredentials = True 
     SmtpServer.EnableSsl = True 
     SmtpServer.Credentials = New Net.NetworkCredential(un, pw) 
     SmtpServer.Port = 25 
     SmtpServer.Host = "smtp.address" 
     mail.From = New MailAddress(sender) 
     mail.To.Add(some address) 
     mail.Subject = subject 
     mail.Body = body 
     mail.Sender = New MailAddress(sender) 
     SmtpServer.Send(mail) 
    Catch 
    End Try 
    End Using 
End Using