vb.net – 当点击“btnLogin”时,我的表单会减小.

Imports System.Data.OleDb
Public Class frmLogin
    Public AdminDetails As Boolean
    Public SuccessfulLoginUsername As String
    Dim provider As String
    Dim dataFile As String
    Dim connString As String
    Dim myConnection As OleDbConnection = New OleDbConnection
    Private Sub btnLogin_Click(sender As Object,e As EventArgs) Handles btnLogin.Click
        provider = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source ="

        dataFile = Application.StartupPath & "SAC1 Database.mdb"
        connString = provider & dataFile
        myConnection.ConnectionString = connString


        Dim cmd As OleDbCommand = New OleDbCommand("SELECT * FROM [tblUsers] WHERE [Username] = '" & txtUsername.Text & "' AND [Password] = '" & txtPassword.Text & "'",myConnection)
        myConnection.Open()
        Dim dr As OleDbDataReader = cmd.ExecuteReader
        Dim userFound As Boolean = False
        Dim FirstName As String = ""
        Dim LastName As String = ""

        While dr.Read
            userFound = True
            FirstName = dr("FirstName").ToString
            LastName = dr("LastName").ToString
        End While

        If userFound = True Then
            If txtUsername.Text = "admin" And txtPassword.Text = "password" Then
                AdminDetails = True
                SuccessfulLoginUsername = txtUsername.Text
            Else
                AdminDetails = False
                SuccessfulLoginUsername = txtUsername.Text
            End If
            frmMenu.Show()
            frmMenu.lblTitle.Text = "Welcome " & FirstName & " " & LastName
            frmMenu.lblGreeting.Text = "Howdy! " & FirstName & " " & LastName & ". What would you like to do today?"
        Else
            MsgBox("Sorry,username or password not found",MsgBoxStyle.OkOnly,"Invalid Login")
        End If
        myConnection.Close()
    End Sub

    Private Sub btnExit_Click(sender As Object,e As EventArgs) Handles btnExit.Click
        Close()
        End
    End Sub

    Private Sub linklblCreateAccount_LinkClicked(sender As Object,e As LinkLabelLinkClickedEventArgs) Handles linklblCreateAccount.LinkClicked
        frmCreateAccount.Show()
    End Sub
End Class