VB.net & Microsoft Sql问题

js_lee

我现在做到的是用button去捉资料。请问我要怎样改我才可以不用button直接standby在那里等捉资料？？timer可以吗？我之前试过用timer捉可是一直有问题。希望各位帮帮我。。。谢谢^^下面是我的source code。我用的是Microsoft visual studio 2008跟它里面的microsoft sql database.


Public Class Form1

    Private Sub loginButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles loginButton.Click
        Dim connection As New SqlClient.SqlConnection
        Dim command As New SqlClient.SqlCommand
        Dim adaptor As New SqlClient.SqlDataAdapter
        Dim dataset As New DataSet
        Dim theDate As Date


        Dim readit As Byte
        Dim i As Integer
        Label1.Text = ""

        While (i <= 11)
            readit = SerialPort1.ReadByte()
            If readit > -1 Then Label1.Text = Label1.Text & readit

            i += 1

        End While

        usernameTextBox.Text = Label1.Text

        connection.ConnectionString = ("Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\Members.mdf;Integrated Security=True;User Instance=True")
        command.CommandText = "SELECT * FROM [User] WHERE Username= '" & usernameTextBox.Text & "'AND Password='" & passwordTextBox.Text & "';"
        connection.Open()

        command.Connection = connection

        adaptor.SelectCommand = command
        adaptor.Fill(dataset, "0")

        Dim count = dataset.Tables(0).Rows.Count

        If count > 0 Then
            MsgBox("Login succesful, welcome.", MsgBoxStyle.Information)
            SerialPort1.RtsEnable = True
            SerialPort1.DtrEnable = True
            theDate = Date.Now()
            TimerOpenCloseDoor.Enabled = True

        Else
            MsgBox("Incorrect login, please check your username and password.", MsgBoxStyle.Critical)
            usernameTextBox.Clear()
            passwordTextBox.Clear()
            SerialPort1.RtsEnable = False
            SerialPort1.DtrEnable = False
        End If

    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        If SerialPort1.IsOpen Then
            SerialPort1.Close()
        End If

        Try
            SerialPort1.Open()
        Catch ex As Exception
            MsgBox("Fail to open serial port")
        End Try
    End Sub

    Private Sub TimerOpenCloseDoor_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TimerOpenCloseDoor.Tick

        SerialPort1.RtsEnable = False
        SerialPort1.DtrEnable = False
        TimerOpenCloseDoor.Enabled = False
    End Sub
End Class

doktorkoo

回复 1# js_lee


    不太明白你的意识。。。如果不要button 按才读取资料，可以用form load 方法来试试看

宅男-兜着走

我现在做到的是用button去捉资料。请问我要怎样改我才可以不用button直接standby在那里等捉资料？？timer可 ...
js_lee 发表于 21-10-2010 02:07 AM

   1 楼正解， 请使用 Form Load Event， 不然就 你 Construct 的时候， 直接 Load 资料。

Reader

Window Services....

js_lee

谢谢大家的教导...我做到了...麻烦大家了～