在 Visual basic 中创建注册和登录页面

Question

我正在尝试在 Visual Basic 中创建用户名和密码注册和登录页面。我需要页面在文本框中输入用户名和密码后将其存储在数组中。我还需要用户名是唯一的，并且只能放入数组一次。之后，使用登录按钮，我需要它在可以感知数组中的用户名和密码后显示授予的访问权限。这是我到目前为止的代码。我可以输入用户名一次，但之后无论用户名不同还是相同，我都会弹出错误消息框。

Public Class WebForm1
    Inherits System.Web.UI.Page
    Public Shared Username(50) As String
    Public Shared password(50) As String
    Public Shared count As Integer = 0
    Public Shared count1 As Integer = 0
    Public Shared UN As String
    Public Shared PW As String
    Protected Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim UN As String
        Dim PW As String

        If TextBox1.Text = Nothing Then
            MsgBox("Please enter a Username to register", vbExclamation, "Error")
            Exit Sub
        End If

        If TextBox2.Text = Nothing Then
            MsgBox("Please enter a password to register", vbExclamation, "Error")
            Exit Sub
        End If

        For i As Integer = 0 To count - 1
            If Username(i) = UN Then
                MsgBox("This Username has already been used! Please enter a new Username", vbExclamation, "Error")
            End If
        Next

        Username(count) = UN
        count += 1

        password(count1) = PW
        count1 += 1

    End Sub

    Protected Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click

        For i As Integer = 0 To count - 1
            If Username(i) = UN & password(i) = PW Then
                MsgBox("Access Granted")
            End If
        Next


    End Sub
End Class

Answer 1

&

连接字符串，使用

AndAlso

或

OrElse

进行布尔运算。

If Username(i) = UN AndAlso password(i) = PW Then
    MsgBox("Access Granted")
End If