VB.NET使用參數化存儲過程在Combobox中顯示查詢結果

Question

我想在我的Combobox中顯示我的查詢結果，但是我收到錯誤「無效參數或沒有傳遞參數」。任何意見是極大的讚賞。這是我的代碼。

Private Sub frmAdvancePayment_Load(sender As Object, e As EventArgs) Handles MyBase.Load 
    lstBillNum.Items.Clear() 
    txtLName.Text = frmAmortizationFee.txtLName.Text 
    txtFName.Text = frmAmortizationFee.txtFName.Text 
    lblMaAmount.Text = frmAmortizationFee.txtAmort.Text 
    lblAcctNum.Text = frmAmortizationFee.cmbAccountNo.Text 


    Dim connection_string As String = "Data Source=.\sqlexpress;Initial Catalog=CreditAndCollection;Integrated Security=True" 

    Dim Connection As New SqlConnection(connection_string) 
    Dim da As New SqlDataAdapter 
    Dim command As New SqlCommand 
    command.Connection = Connection 

    command.CommandText = "showBillingNum" 
    command.CommandType = CommandType.StoredProcedure 
    command.Parameters.AddWithValue("@AcctNum", lblAcctNum.Text) 

    Connection.Open() 

    da.SelectCommand = command 
    Dim dt As New DataSet 
    da.Fill(dt) 

    cmbBillNum.DataSource = dt 

    cmbBillNum.DisplayMember = "BillNum" 
    cmbBillNum.ValueMember = "BillNum" 
    command.ExecuteNonQuery() 
    Connection.Close() 

End Sub 

Answer 1

我猜想它正在工作，但你仍然得到錯誤？這是因爲第三行到最後一行：

command.ExecuteNonQuery() 

在已經運行後執行查詢。不知道爲什麼會產生這樣的錯誤，但我知道這條線是錯誤的。