已经有一个与此命令关联的数据读取器，必须先关闭该数据读取器

Question

大家好，希望有人能帮助我。

我有一个 vb.net 控制台应用程序，最近开始让我头疼。

我有下一个代码：

Imports System.Data.SqlClient
Dim SqlQuery = New StringBuilder
Dim LstResults As New List(Of StoreDate)

SqlQuery.Append("searh something ")

Using Conn As New SqlConnection(CONSTR)
    Conn.Open()
    Using Cmd As New SqlCommand(SqlQuery.ToString, Conn)
        Cmd.Parameters.AddWithValue("@param1", Param1)
        Cmd.Parameters.AddWithValue("@param2", Param2)
        Cmd.Parameters.AddWithValue("@Param3", Param3)
        Cmd.CommandTimeout = 0
        Using Reader As SqlDataReader = Cmd.ExecuteReader()
            While Reader.Read()
                LstResults.Add(New StoreDate(Reader!Store, Reader!Date))
            End While
        End Using
    End Using
    Conn.Close()
End Using

If LstResults.Count > 0 Then
    Try
        Using Conn As New SqlConnection(CONSTR)
            Conn.Open()
            For Each Result As StoreDate In LstResults
                Store = Result.Store
                Date = Result.Date
                Using Cmd = New SqlCommand("STORE_PROCEDURE", Conn)
                    Cmd.CommandType = CommandType.StoredProcedure
                    Cmd.CommandTimeout = 0
                    Cmd.Parameters.AddWithValue("@Date", DateStore)
                    Cmd.Parameters.AddWithValue("@Store", Tienda)
                    Cmd.ExecuteNonQuery()
                End Using
            Next
            Conn.Close()
        End Using
    Catch ex As Exception
        log("Error: " & ex.Message, alog)
    End Try
End If

SqlQuery.Clear()
LstResults.Clear()
Try
    SqlQuery.Append("do another search ")
    Using Conn As New SqlConnection(CONSTR)
        Conn.Open()
        Using Cmd = New SqlCommand(SqlQuery.ToString, Conn)
            Cmd.Parameters.AddWithValue("@param1", Param1)
            Cmd.Parameters.AddWithValue("@param2", Param2)
            Cmd.Parameters.AddWithValue("@Param3", Param3)
            Cmd.CommandTimeout = 0
            Using Reader As SqlDataReader = Cmd.ExecuteReader()
                While Reader.Read()
                    LstResults.Add(New StoreDate(Reader!Store, Reader!Date))
                End While
            End Using
        End Using
        Conn.Close()
    End Using

Catch ex As Exception
    log("Error: " & ex.Message , alog)
    Environment.Exit(ex.HResult)
End Try

但是当它到达第二个数据读取器时，我收到错误：“已经有一个与此命令关联的数据读取器必须首先关闭”，这对我来说没有意义，“使用”应该处理对象完成后，不是吗？我在这里错过了一些愚蠢的事情吗？我希望有人能帮助我，我自己已经走到了死亡的尽头。

我所做的唯一更改是从数据表切换到列表，StoreDate是下一个简单的类，但与错误无关，它在点击第二个“Using Reader As SqlDataReader”后出现

Public Class StoreDate
    Private _Store As String
    Private _Date As DateTime


    Public Property Store As String
        Get
            Return _Store
        End Get
        Set(value As String)
            _Store = value
        End Set
    End Property
    Public Property Date As DateTime
        Get
            Return _Date
        End Get
        Set(value As DateTime)
            _Date = value
        End Set
    End Property
    Public Sub New(ByVal Store As String, ByVal Date As DateTime)
        _Store = Store
        _Date = Date
    End Sub

End Class

Answer 1

按照建议，我只打开一个连接，为了确定，切换到这样的数据表：

'Using Reader As SqlDataReader = Cmd.ExecuteReader()

' While Reader.Read() ' LstStoreDate.Add(New StoreDate(Reader!Store, Reader!DATE)) ' 结束同时 '结束使用 TblStoreDate.Load(Cmd.ExecuteReader())

但在进入“TblStoreDate.Load(Cmd.ExecuteReader()”后不断收到相同的错误...我想这给了我要搜索什么的线索，只需弄清楚那是什么线索