我在 vb.net 中不断收到“连接字符串未正确初始化”错误，我不知道如何修复它。我也在尝试自动生成数字。例如，在我的表中，一旦我点击添加新它应该按顺序生成下一个数字。
这是我的代码：
Imports System.Data
Imports System.Data.OleDb
Imports System.Data.SqlClient
Public Class AddTemplate
Private Property OleDbConnection As Object
Private Property temp As Object
Dim dc As New OleDbConnection
Dim drd As OleDbDataReader
Dim conn As SqlConnection
Dim cmd As SqlCommand
Dim da As SqlDataAdapter
Dim ds As DataSet
Dim i As Integer = 0
Private Sub TemplateNameTextBox_TextChanged(sender As Object, e As EventArgs)
Try
Catch ex As Exception
End Try
End Sub
Private Sub SearchButton_Click(sender As Object, e As EventArgs) Handles SearchButton.Click
End Sub
Public Sub Button1_Click(sender As Object, e As EventArgs) Handles SaveButton.Click
ValueSourcesBindingSource.EndEdit()
Me.Update()
End Sub
Private Sub CancelButton_Click(sender As Object, e As EventArgs) Handles CancelButton.Click
Me.Close()
End Sub
Private Function ValueSourcesDataTable() As Object
Me.Update()
End Function
Private Sub ValueSourcesBindingNavigatorSaveItem_Click(sender As Object, e As EventArgs)HandlesValueSourcesBindingNavigatorSaveItem.Click
Me.Validate()
Me.ValueSourcesBindingSource.EndEdit()
Me.TableAdapterManager.UpdateAll(Me.ValueTrackerDataSet)
End Sub
Private Sub AddTemplate_Load(sender As Object, e As EventArgs) Handles MyBase.Load
'TODO: This line of code loads data into the 'ValueTrackerDataSet.ValueSources' table. You can move, or remove it, as needed.
Me.ValueSourcesTableAdapter.Fill(Me.ValueTrackerDataSet.ValueSources)
End Sub
Private Sub ValueSourcesDataGridView_CellContentClick(sender As Object, e As DataGridViewCellEventArgs) Handles ValueSourcesDataGridView.CellContentClick
End Sub
Public Sub AutoNumberNo()
Dim myReader As SqlDataReader
conn = GetConnect()
conn.Open()
Dim comm As SqlCommand = New SqlCommand(Sql, conn)
myReader = comm.ExecuteReader
Try
If myReader.HasRows Then
While myReader.Read()
temp = myReader.Item("ValueSourceID") + 1
End While
Else
End If
temp = 1
End
myReader.Close()
Catch ex As Exception
End Try
conn.Close()
ValueSourceIDTextBox.Text = String.Concat(temp) ' result will appear in textbox txtId
'declare variables
Dim randomvalue As New Random 'create random object
Dim randomhold As Integer
'generate random number
For i As Integer = 0 To 9999
randomhold = randomvalue.Next(1, 9999)
ValueSourceIDTextBoxId.Text = randomhold & " " & DateTime.Now.Minute & " " & DateTime.Now.Year
Next
End Sub
Private Sub BindingNavigatorMoveNextItem_Click(sender As Object, e As EventArgs) Handles BindingNavigatorMoveNextItem.Click
End Sub
Private Sub ValueSourceIDTextBox_TextChanged(sender As Object, e As EventArgs) Handles ValueSourceIDTextBox.TextChanged
End Sub
Private Function GetConnect() As Object
Throw New NotImplementedException
End Function
Private Function Sql() As Object
Throw New NotImplementedException
End Function
Private Sub ToolStripButton1_Click(sender As Object, e As EventArgs) Handles ToolStripButton1.Click
End Sub
Private Sub ToolStripProgressBar1_Click(sender As Object, e As EventArgs)
End Sub
Private Sub BindingNavigatorMovePreviousItem_Click(sender As Object, e As EventArgs) Handles BindingNavigatorMovePreviousItem.Click
End Sub
Private Sub BindingNavigatorAddNewItem_Click(sender As Object, e As EventArgs) Handles BindingNavigatorAddNewItem.Click
Dim conn As New OleDbConnection
Dim connectionstring = ("Data Source=wal1sql1;Initial Catalog=ValueTracker;Integrated Security=True")
conn.Open()
Dim query As String = "Select IsNULL(Max(0+1), 0) ValueSourceID from ValueSourcesDataTable"
Dim dr As SqlClient.SqlDataReader
Dim cmd As New SqlCommand(query, SqlConnection)
dr = cmd.ExecuteReader
dr.Read()
ValueSourcesDataTable.Text = dr("ValueSourceID").ToString
conn.Close()
End Sub
Private Function ValueSourceIDTextBoxId() As Object
Throw New NotImplementedException
End Function
Private Function SqlConnection() As Object
Throw New NotImplementedException
End Function
End Class