Question

这是我正在做的家庭作业。我有一个.mdb文件应该连接到我的应用程序，然后我应该能够在记录之间导航。数据库作为数据源连接。但是，当我运行应用程序时，没有填充任何数据，当我按下工具条上的按钮时，我得到一个未处理的IndexOutOfRangeException错误。我试图向教授寻求帮助，但她在整个学期都不存在。我在这做错了什么？我只是寻求帮助，以便集中注意力，以便我可以自己解决这个问题。

Public Class Form1

Dim strMemoryConnection As String = "Provider = Microsoft.Jet.OLEDB.4.0; Data Source = " &
    Application.StartupPath & "\memory.mdb"
Dim strSQLMem As String
Dim dtMem As New DataTable()
Dim intTotalRows As Integer
Dim intCurrentRow As Integer

Private Sub displayRecord()
    Me.txtTitle.Text = CStr(dtMem.Rows(intCurrentRow)("title"))
    Me.txtAuthor.Text = CStr(dtMem.Rows(intCurrentRow)("author"))
    Me.txtPublisher.Text = CStr(dtMem.Rows(intCurrentRow)("publisher"))
    Me.txtStuff.Text = CStr(dtMem.Rows(intCurrentRow)("stuff"))
End Sub

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventHandler)
    dtMem.Clear()
    strSQLMem = "SELECT * FROM Memory"
    Dim dataAdapter As New OleDb.OleDbDataAdapter(strSQLMem, strMemoryConnection)
    dataAdapter.Fill(dtMem)
    dataAdapter.Dispose()
    intTotalRows = dtMem.Rows.Count
    intCurrentRow = 0
    displayRecord()
End Sub

#Region "Tool Strip Button Clicks"
Private Sub btnTop_Click(sender As Object, e As EventArgs) Handles btnTop.Click
    intCurrentRow = 1
    displayRecord()
End Sub

Private Sub btnPrev_Click(sender As Object, e As EventArgs) Handles btnPrev.Click
    intCurrentRow = intCurrentRow - 1
    If intCurrentRow < 0 Then
        intCurrentRow = 1
    End If
    displayRecord()
End Sub

Private Sub btnNext_Click(sender As Object, e As EventArgs) Handles btnNext.Click
    intCurrentRow = intTotalRows + 1
    If intCurrentRow = intTotalRows Then
        intCurrentRow = intTotalRows - 1
    End If
    displayRecord()
End Sub

Private Sub btnBot_Click(sender As Object, e As EventArgs) Handles btnBot.Click
    intCurrentRow = intTotalRows - 1
    displayRecord()
End Sub
#End Region
End Class

Answer 1

In the end, it was as I expected. The data was not loading properly. I finally realized that the Form1_Load argument was not correct.

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventHandler)

Needed to be:

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

I will be letting my professor and fellow classmates know that this is incorrect.

Thanks to Bugs for the troubleshooting. At the least, I now know how to create a SQL connection very easily. I also appreciate whomever downvoted my question and their help in figuring this out.

为什么我的表单没有从.mdb文件加载数据？

1 个答案: