如果“连接未关闭”错误，请关闭连接？ [英] Close connection if there is an error 'connection not closed'?

问题描述

我的vb.net应用程序显示错误。



连接未关闭。连接的当前状态已打开

这是我的码。请帮我纠正错误：

My vb.net application shows an error.

"Connection not closed. Connection's current state is open"
Here is my code. Please help me rectify the error:

Private Sub saveBtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles          saveBtn.Click
        addSubject()
       End Sub

    Private Function addSubject() As Boolean
      Dim cmd As New SqlCommand
      Dim ok As Boolean = False
      cmd.Connection = con
      cmd.CommandText = " INSERT INTO Subjects(subject_name) VALUES(@inn)"
      cmd.CommandType = CommandType.Text
      cmd.Parameters.AddWithValue("inn", subjectTxt.Text)

      Try
        con.Open()
        cmd.ExecuteNonQuery()
        ok = True

      Catch ex As Exception
          MessageBox.Show(ex.Message, "Add failed")
         ok = False
       End Try
      cmd.Dispose()
      con.Close()
      Return ok

      con.Close()
    End Function

推荐答案

嗨
ur尝试打开连接，但是该连接已经打开，它没有处于关闭状态，所以删除con.open并尝试



删除任何一个con.Close（）表单catch块。



你在哪里声明con？你把con声明为公共变量吗？

Hi u r try to open connection,but that connection is already opened,it not in close state,so remove con.open and try

Remove any one con.Close() form catch block.

Where u declare con ? did u declare con as public variable ?

将连接声明为Public，然后如果有任何东西打开则先关闭连接然后打开它

declare connection as Public ,then First close connection if anything is open Then Open it

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