OLEDB連接是未處理的錯誤

Question

我想將一些數據庫記錄鏈接到文本框和一個帶有Visual Basic和OLEDB的列表框，但是當我調試程序時，即使數據庫位於bin/debug文件夾中，程序也不會識別它。

下面是代碼：

Imports System.Data.OleDb 
Public Class Form1 

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load 
     Dim ConnectString As String = "Provider = Microsoft.Jet.OLEDB.4.0;" & _ 
     "Data Source = Hospital.mdb" 
     Dim dtPatientsIDs As New DataTable 
     Dim daPatientIDs As New OleDbDataAdapter _ 
     ("Select [Patient ID] From Patients", ConnectString) 

     daPatientIDs.Fill(dtPatientsIDs) 
     lstPatientIDs.DataSource = dtPatientsIDs 
     lstPatientIDs.DisplayMember = "Patient ID" 

     OleDbDataAdapter1.Fill(DsPatientsAndWards1) 
     txtWardName.DataBindings.Add("Text", DsPatientsAndWards1, _ 
           "Patients.Ward Name") 
     txtWardType.DataBindings.Add("Text", DsPatientsAndWards1, _ 
           "Patients.Ward Type") 



    End Sub 

    Private Sub btnPrevious_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnPrevious.Click 
     BindingContext(DsPatientsAndWards1, "Patients").Position = _ 
     BindingContext(DsPatientsAndWards1, "Patients").Position - 1 

    End Sub 

    Private Sub btnNext_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnNext.Click 
     BindingContext(DsPatientsAndWards1, "Patients").Position = _ 
     BindingContext(DsPatientsAndWards1, "Patients").Position + 1 
    End Sub 

    Private Sub btnFind_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnFind.Click 
     Dim index As Short 
     index = lstPatientIDs.SelectedIndex 
     BindingContext(DsPatientsAndWards1, "Patients").Position = index 

    End Sub 
End Class 

here is the error and its location

Answer 1

嘗試改變

Dim daPatientIDs As New OleDbDataAdapter _ 
    ("Select [Patient ID] From Patients", ConnectString) 

到

Dim Con as NEW OleDBConnection(ConnectionString) 
Dim daPatientIDs As New OleDbDataAdapter _ 
    ("Select [Patient ID] From Patients", Con) 

，並添加

Con.open() 

前

OleDbDataAdapter1.Fill(DsPatientsAndWards1)