mysql - InvalidArgument= '11209485' 的值对于 'index' 无效。参数名称 : index error when running SQL query in VB. NET

Question

当我尝试从数据库检索卡号并将其放入组合中时，我不断收到此错误“无法通信 InvalidArgument=‘11209485’的值对于‘index’无效。参数名称:index”框，以便用户可以在 VB.NET 2012 中选择他们的卡号。 11209485 是数据库中的第一个卡号，所以我认为连接正常，但我根本不理解这个错误。

对于此事的任何帮助，我将不胜感激。谢谢!

导入 MySql.Data

导入MySql.Data.MySqlClient

公开课表格1

Dim dbCon As MySqlConnection
Dim strQuery As String = ""
Dim SQLcmd As MySqlCommand
Dim DataReader As MySqlDataReader

' load application Form
Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load

    'Prepare connection and query
    Try
        dbCon = New MySqlConnection("Server=localhost;Database=***;Uid=***;Pwd=***")

        strQuery = "SELECT CardNumber " &
                   "FROM Account"

        SQLcmd = New MySqlCommand(strQuery, dbCon)

        'Open the connection
        dbCon.Open()

        ' create database reader to read information from database
        DataReader = SQLcmd.ExecuteReader

        ' fill ComboBox with account numbers
        While DataReader.Read
            cboAccountNumbers = cboAccountNumbers.Items(DataReader("CardNumber"))
        End While

        'Close the connection
        DataReader.Close()
        dbCon.Close()

    Catch ex As Exception

        MsgBox("Failure to communicate" & vbCrLf & vbCrLf & ex.Message)


    End Try
End Sub

下课

Answer 1

错误在这一行:

cboAccountNumbers = cboAccountNumbers.Items(DataReader("CardNumber"))

您正在尝试读取组合框中的第 11209485 个项目，但项目数量并不多。试试这个:

cboAccountNumbers.Items.Add(DataReader("CardNumber"))