Question

我正在创建一个用于计算学校课程作业的帐户检索程序，该程序检查输入的电子邮件地址和密码与存储在CSV文件中的程序，如果输入正确则程序显示其用户信息，如果输入是不正确它会输出一条错误消息告诉他们。我已经在Visual Basic中创建了程序并且它工作正常，除非我按下提交而不在输入字段中输入任何内容。如果未输入任何内容，程序将调用错误消息以进行无输入，并输出错误消息以查看无效/错误输入。我该如何解决？我的代码如下：

Imports System.Text.RegularExpressions

Public Class Form1

Private Sub Label2_Click(sender As Object, e As EventArgs) Handles Password.Click

End Sub

Private Sub Label1_Click(sender As Object, e As EventArgs) Handles EmailAddress.Click

End Sub



Private Sub Submit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Submit.Click
    Dim currentRow As String()
    Dim foundmatch As Boolean

    Using parserDetails As New Microsoft.VisualBasic.FileIO.TextFieldParser("CSV_File.csv")
        parserDetails.SetDelimiters(",")

        While Not parserDetails.EndOfData
            currentRow = parserDetails.ReadFields()

            If (Not String.IsNullOrWhiteSpace(EmailAddress.Text)) Then
                If EmailAddress.Text = currentRow(0) And Password.Text = currentRow(1) Then
                    Me.InfoDisplay.Rows.Add(currentRow)
                    foundmatch = True
                    Exit While
                End If
            Else 'null/empty or white space
                MsgBox("You need to type something into the input boxes")
                foundmatch = False
                Exit While
            End If
        End While
    End Using

    If Not foundmatch Then
        MsgBox("The email and/or password entered cannot be found or is incorrect.", MsgBoxStyle.Critical, "Invalid Email")
    End If
End Sub




Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load

End Sub

Private Sub Input(p1 As String)
    Throw New NotImplementedException
End Sub

Private Sub Reset_Click(sender As Object, e As EventArgs) Handles Reset.Click
    EmailAddress.Text = Nothing
    Password.Text = Nothing
    InfoDisplay.Rows.Clear()

    End Sub
End Class

Answer 1

当您输入任何内容时，您将在csv中第一行的循环（空/空或空格）循环中以你的else情况结束，因此消息框＆＃34;您需要输入进入输入框的东西＆＃34;将显示并且另外foundmatch将为False，这将导致＆＃34;输入的电子邮件和/或密码无法找到或不正确。＆＃34;显示。

要解决此问题，我建议将空格检查移出While循环，如果输入为空则跳过所有其他操作。

VB帐户检索程序输出两个错误消息

1 个答案: