رقابة قاعدة البيانات (التحديث التلقائي للبيانات ) SqlDependency

كود :

 Private Delegate Sub UICallback()



    Private Const CS As String = "Data Source=.;Initial Catalog=mydb;Integrated Security=True"

    Private Const QuerySelect As String = "SELECT id,nameFROM my_tab "

كود :

 Private Sub StartChecking()



        Dim cn As SqlClient.SqlConnection = Nothing

        cn = New SqlClient.SqlConnection(CS)



        Dim dad As New SqlClient.SqlDataAdapter(QuerySelect, cn)



        Dim dependency As New SqlClient.SqlDependency(dad.SelectCommand)



        AddHandler dependency.OnChange, AddressOf Me.OnNotificationChange



        SqlClient.SqlDependency.Start(CS)



        Dim ds As New DataSet

        dad.Fill(ds)

    End Sub



    Private Sub OnNotificationChange(ByVal sender As Object, ByVal e As SqlClient.SqlNotificationEventArgs)









        Dim dependency As SqlDependency = DirectCast(sender, SqlDependency)



        RemoveHandler dependency.OnChange, AddressOf Me.OnNotificationChange



        Me.Invoke(New UICallback(AddressOf FillGrid))

        StartChecking()



    End Sub

' تحميل البيانات 

    Private Sub FillGrid()

        Using conn As New SqlConnection(CS)

            conn.Open()

            Using cm As New SqlCommand(QuerySelect, conn)

                Using adapter As New SqlDataAdapter(cm)

                    Dim ds As New DataSet

                    adapter.Fill(ds)

                    DataGridView1.DataSource = ds.Tables(0)

                End Using

            End Using

        End Using

    End Sub



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

        FillGrid()

        StartChecking()

    End Sub

'عند اغلاق النافذه

    Private Sub Form1_FormClosing(ByVal sender As System.Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles MyBase.FormClosing

        SqlClient.SqlDependency.Stop(CS)

    End Sub