Use-of-the-WaitAny-method-of-processing-multiple-asynchronous-processes-VB


            <%@ Page Language="VB" %>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SqlClient" %>
<%@ Import Namespace="System.Configuration" %>

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) 
        Dim DBCon As SqlConnection
        Dim OrdersCommand As SqlCommand = New SqlCommand()
        Dim CustCommand As SqlCommand = New SqlCommand()
        Dim OrdersReader As SqlDataReader
        Dim CustReader As SqlDataReader
        Dim OrdersASyncResult As IAsyncResult
        Dim CustAsyncResult As IAsyncResult
        Dim WHIndex As Integer
        Dim WHandles(1) As Threading.WaitHandle
        Dim OrdersWHandle As Threading.WaitHandle
        Dim CustWHandle As Threading.WaitHandle
        DBCon = New SqlConnection()
        DBCon.ConnectionString = ConfigurationManager.ConnectionStrings("DSN_NorthWind").ConnectionString
        CustCommand.CommandText = " SELECT * FROM Customers WHERE CompanyName = 'A' "
        CustCommand.CommandType = CommandType.Text
        CustCommand.Connection = DBCon
        OrdersCommand.CommandText = _
                " SELECT Customers.CompanyName, Customers.ContactName, " & _
                " Orders.OrderID, Orders.OrderDate, " & _
                " Orders.RequiredDate, Orders.ShippedDate " & _
                " FROM Orders, Customers " & _
                " WHERE Orders.CustomerID = Customers.CustomerID " & _
                " AND Customers.CompanyName = 'Alfreds Futterkiste' " & _
                " ORDER BY Customers.CompanyName, Customers.ContactName "
        OrdersCommand.CommandType = CommandType.Text
        OrdersCommand.Connection = DBCon
        DBCon.Open ()
        CustAsyncResult = CustCommand.BeginExecuteReader()
        OrdersASyncResult = OrdersCommand.BeginExecuteReader()
        CustWHandle = CustAsyncResult.AsyncWaitHandle
        OrdersWHandle = OrdersASyncResult.AsyncWaitHandle
        WHandles(0) = CustWHandle
        WHandles(1) = OrdersWHandle
        For Index As Integer = 0 To 1
            WHIndex = Threading.WaitHandle.WaitAny(WHandles)
            Select Case WHIndex
                Case 0
                    CustReader = CustCommand.EndExecuteReader(CustAsyncResult)
                    gvCustomers.DataSource = CustReader
                    gvCustomers.DataBind()                    
                Case 1
                    OrdersReader = _
                       OrdersCommand.EndExecuteReader(OrdersASyncResult)
                    gvOrders.DataSource = OrdersReader
                    gvOrders.DataBind()
            End Select
        Next
        DBCon.Close()
    End Sub



    The Wait Any Approach


    
    
    
    
            Runat="server">
        
                    DataField="CompanyName">
                    DataField="ContactName">
                    DataFormatString="{0:d}">
                    DataFormatString="{0:d}">
                    DataFormatString="{0:d}">
        
    
    

    


File: Web.config

  
                     connectionString="Data Source=localhost\SQLEXPRESS;Initial Catalog=Northwind;Integrated Security=True"
             providerName="System.Data.SqlClient" />
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