VB.NET使用Paramaterized存储过程在Combobox中显示查询结果

Question

我想在我的Combobox中显示查询结果但是我收到错误“无效参数或没有参数传递”。任何意见是极大的赞赏。这是我的代码。

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

我猜它会起作用，但你仍然得到错误？这是因为第3行到最后一行：

command.ExecuteNonQuery()

在已经运行后执行查询。不知道为什么会产生这个错误，但我知道这条线是错误的。