Question

我制作了一个电子邮件程序。当我启动它时，它给我这个错误消息：

Menü（VB Version 1.0）.exe中出现未处理的'System.InvalidOperationException'类型异常

我的代码

Imports System.Net.Mail
Public Class Email
    Dim Tárgy As String = TextBox4.Text
    Dim Üzenet As String = TextBox5.Text
    Dim UserEmail As String = TextBox1.Text
    Dim UserPass As String = TextBox2.Text
    Dim ToEmail As String = TextBox3.Text
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        Dim MyMailMessage As New MailMessage()
        Try
            MyMailMessage.From = New MailAddress(UserEmail)
            MyMailMessage.To.Add(ToEmail)
            MyMailMessage.Subject = (Tárgy)
            MyMailMessage.Body = (Üzenet)
            Dim SMTP As New SmtpClient("smtp.gmail.com")
            SMTP.Port = 587
            SMTP.EnableSsl = True
            SMTP.Credentials = New System.Net.NetworkCredential((UserEmail), (UserPass))
            SMTP.Send(MyMailMessage)
        Catch ex As Exception
        End Try
    End Sub
End Class

Answer 1

在Click事件中移动字符串的初始化。您之前不需要它们并且在全局级别执行它将导致异常，因为TextBox和其他控件尚未初始化

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

    Dim Tárgy As String = TextBox4.Text
    Dim Üzenet As String = TextBox5.Text
    Dim UserEmail As String = TextBox1.Text
    Dim UserPass As String = TextBox2.Text
    Dim ToEmail As String = TextBox3.Text

    Dim MyMailMessage As New MailMessage()
    ....            
    SMTP.Send(MyMailMessage)
End Sub

此外，如果您不对异常做任何事情，请不要使用空的trt / catch块。如果发生异常，则您无法看到错误。

发生了类型为“System.InvalidOperationException”的未处理异常

1 个答案: