ExecuteReader 需要一个打开且可用的连接 - 当前状态已关闭

Question

所有。
自从昨晚很晚才提出这个问题以来，我一直在努力解决这个问题。
不确定为什么会发生，但确实如此。过去只使用一个 Artistcon.open()
现在要求我在每个新 "ExecuteReader".
都拥有它下面是代码示例。从连接字符串开始，然后是实际代码。
我在下面标记了一行，以便于查找。

我试图将 ArtistCon.open() 放在代码区域内，在该区域的 select 语句上方，但它出错了，

web.config => database.config

<connectionStrings>
<add name ="Local" connectionString="Data Source=ServerName\InstanceName;Database=DatabaseName;User ID=UserName;Password=********;MultipleActiveResultSets=True"/>
</connectionStrings>

default.vb.aspx

Dim Artistcon As New SqlConnection
Artistcon = New SqlConnection(ConfigurationManager.ConnectionStrings("Local").ConnectionString)

    Artistcon.Open()
    Dim chWriters As New SqlCommand("SELECT TrackID, WID FROM Tracks WHERE (TrackFileName = @TrackFileName)", Artistcon)
   chWriters.Parameters.Add(New SqlParameter("@TrackFileName", getfile & ".mp3"))
    Dim rschhWriters As SqlDataReader
     rschhWriters = chWriters.ExecuteReader(Data.CommandBehavior.CloseConnection)
     If rschhWriters.Read() Then

     Dim sW As String = strWriters
     Dim leftString = sW.Substring(0, sW.IndexOf("["))
     Dim Wparts As String() = leftString.Split(New Char() {"/"c})

                        ' Loop through result strings with For Each.
     Dim Wpart As String

     For Each Wpart In Wparts
     Dim theWriters As String = Replace(Wpart, " ", "_")

     Dim getWriters As New SqlCommand("SELECT WritersID, WName FROM Writer WHERE (WName = @WName)", Artistcon)
     getWriters.Parameters.Add(New SqlParameter("@WName", theWriters.TrimEnd(CChar("_"))))
     Dim rsWriters As SqlDataReader
     ' =================ERROR LINE BELOW=================
     ' ExecuteReader requires an open and available Connection. The connection's current state is closed.
     rsWriters = getWriters.ExecuteReader(Data.CommandBehavior.CloseConnection) <<< ERROR LINE
     ' =================ERROR LINE ABOVE=================
     If Not rsWriters.Read() Then ' If record exist

     lblWriter.Text = "Insert WName=" & Wpart
     strWriters = "INSERT INTO Writer(WName)VALUES(@WName)"
     WriterCMD = New SqlCommand(strWriters, Artistcon)
     WriterCMD.Parameters.Add(New SqlParameter("@WName", theWriters.TrimEnd(CChar("_"))))
     Try
       WriterCMD.ExecuteNonQuery()
     Catch ex As Exception
     Finally

    End Try
    End If
    rsWriters.Close()
    getWriters.Dispose()

之前我对这段代码没有任何问题，直到我开始添加并更改代码，然后突然之间，我开始在每个嵌套记录上都遇到这个错误，不得不把 ArtistCon.open() 在每个 ExecuteReader 上，然后我在嵌套语句中得到这个。

谢谢。

Answer 1

您特别要求关闭与此电话的连接：

Dim rschhWriters As SqlDataReader
rschhWriters = chWriters.ExecuteReader(Data.CommandBehavior.CloseConnection)

所以尝试将其更改为

Dim rschhWriters As SqlDataReader = chWriters.ExecuteReader()

注意：请使用 Using - End Using 积木来使用您的一次性物品。您空的 Try-Catch 也有问题，因为您隐藏了以后难以调试的问题。您想查看任何异常，以便您可以更改代码以防止它们发生。

ExecuteReader 需要一个打开且可用的连接 - 当前状态已关闭

ExecuteReader requires an open and available Connection - current state is closed

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