Management of many records

[Fabio Cirillo]

Hi,
since the sql select using the radcombox charged over 1000 records, you can upload a video, when I open the radcombobox, only 10 records at a time? And then you decide to continue to view other records.
Maybe I need to use the property ShowMoreresultsBox = True?
My side code vb net is:

Protected Sub RadComboBox1_ItemsRequested(sender As Object, e As Telerik.Web.UI.RadComboBoxItemsRequestedEventArgs) Handles RadComboBox1.ItemsRequested

 

Dim sqlSelectCommand As String = "SELECT [id], [descrizione] from [tab_categorie] WHERE [descrizione] LIKE @desc + '%' Order By [descrizione]"

  

Dim adapter As New SqlDataAdapter(sqlSelectCommand, ConfigurationManager.ConnectionStrings("TrycontactString").ConnectionString)

 

 adapter.SelectCommand.Parameters.AddWithValue("@desc", e.Text)

 

 Dim dataTable As New DataTable()

 

 adapter.Fill(dataTable)

 For Each dataRow As DataRow In dataTable.Rows

 

 Dim item As New RadComboBoxItem()

 

 item.Text = DirectCast(dataRow("descrizione"), String)

 

item.Value=dataRow("id").ToString()radComboBox1.Items.Add(item)

 

 item.DataBind()

 

 Next
End Sub

 

 

 

While the ASP side code is:

<telerik:RadComboBox ID="RadComboBox1" Runat="server" DropDownWidth="325px"
    EmptyMessage="Choose a Catogory" EnableLoadOnDemand="true" Filter="Contains"
    Height="150" HighlightTemplatedItems="true"
    OnItemsRequested="RadComboBox1_ItemsRequested"
    Width="325px" ErrorMessage="Dato errato" IsCaseSensitive="True">
</telerik:RadComboBox>

 

 

 

 

 

 

[Princy]

Hi,

Try the following code to show a RadComboBox with 10 items at a time.

ASPX:

<telerik:RadComboBox ID="RadComboBox1" runat="server" Width="250" Height="150"
     EmptyMessage="Select a Company" EnableLoadOnDemand="True" ShowMoreResultsBox="true"
     EnableVirtualScrolling="true" OnItemsRequested="RadComboBox1_ItemsRequested"
     label="Server-Side:">
</telerik:RadComboBox>

VB:

Private Const ItemsPerRequest As Integer = 10
Protected Sub RadComboBox2_ItemsRequested(sender As Object, e As RadComboBoxItemsRequestedEventArgs)
    Dim data As DataTable = GetData(e.Text)

    Dim itemOffset As Integer = e.NumberOfItems
    Dim endOffset As Integer = Math.Min(itemOffset + ItemsPerRequest, data.Rows.Count)
    e.EndOfItems = endOffset = data.Rows.Count

    For i As Integer = itemOffset To endOffset - 1
        RadComboBox2.Items.Add(New RadComboBoxItem(data.Rows(i)("CompanyName").ToString(), data.Rows(i)("CompanyName").ToString()))
    Next

    e.Message = GetStatusMessage(endOffset, data.Rows.Count)
End Sub
Private Shared Function GetData(text As String) As DataTable
    Dim adapter As New SqlDataAdapter("SELECT * from Customers WHERE CompanyName LIKE @text + '%'", ConfigurationManager.ConnectionStrings("NorthwindConnectionString").ConnectionString)
    adapter.SelectCommand.Parameters.AddWithValue("@text", text)

    Dim data As New DataTable()
    adapter.Fill(data)

    Return data
End Function
Private Shared Function GetStatusMessage(offset As Integer, total As Integer) As String
    If total <= 0 Then
        Return "No matches"
    End If

    Return [String].Format("Items <b>1</b>-<b>{0}</b> out of <b>{1}</b>", offset, total)
End Function

Hope this helps.

Thanks,
Princy.

[Fabio Cirillo]

thanks
another question if I may, when I open the radcombobox if the records are to be loaded many would like to come out a waiting message like "wait or loading" ... if you use the property LoadingMessage, the message appears only when I'm writing the search key instead I want to appear when you load the entire list, you can do it?

[Fabio Cirillo]

Hello,

I tried your code but when playing 10 records and then I will continue to display the next 10 and so on, does not work, I'll send you my code:

<telerik:RadComboBox ID="Categoria" runat="server" Width="250" Height="150"

EmptyMessage="Select a Company" EnableLoadOnDemand="True" ShowMoreResultsBox="true"

EnableVirtualScrolling="true" OnItemsRequested="Categoria_ItemsRequested"

label="Server-Side:">

Private Const ItemsCategorie As Integer = 10

   Protected Sub Categoria_ItemsRequested(sender As Object, e As Telerik.Web.UI.RadComboBoxItemsRequestedEventArgs) Handles Categoria.ItemsRequested
       Dim data As DataTable = GetDataCategoria(e.Text)

       Dim itemOffset As Integer = e.NumberOfItems

       Dim endOffset As Integer = Math.Min(itemOffset + ItemsCategorie, data.Rows.Count)

       e.EndOfItems = endOffset = data.Rows.Count



       For i As Integer = itemOffset To endOffset - 1

           Categoria.Items.Add(New RadComboBoxItem(data.Rows(i)("descrizione").ToString(), data.Rows(i)("id").ToString()))

       Next



       e.Message = GetStatusMessageCategoria(endOffset, data.Rows.Count)

   End Sub
   Private Shared Function GetDataCategoria(text As String) As DataTable

       Dim sqlSelectCommand As String = "SELECT [id], [descrizione] from [tab_categorie] WHERE [descrizione] LIKE @desc + '%' Order By [descrizione]"

       Dim adapter As New SqlDataAdapter(sqlSelectCommand, ConfigurationManager.ConnectionStrings("TrycontactString").ConnectionString)
       adapter.SelectCommand.Parameters.AddWithValue("@desc", text)

       Dim data As New DataTable()

       adapter.Fill(data)

       Return data

   End Function

   Private Shared Function GetStatusMessageCategoria(offset As Integer, total As Integer) As String

       If total <= 0 Then

           Return "No records"

       End If

       Return [String].Format("Items: <b>1</b>-<b>{0}</b> out of <b>{1}</b>", offset, total)

   End Function

[Nencho]

Hi Fabio,

I have prepared a sample project for you to demonstrate how you could implement an initial Loading Message. In addition, I have prepared the sample, based on the provided snippet of code, in order to show 10 items per request. Please find it attached.


Regards,
Nencho
the Telerik team

[Fabio Cirillo]

Thanks for your help,
I tried using your code and it works but there is a small problem. When I open the radcombox you see the label Loading ... as your code but I radcombox set in the properties of the voice LoadingMessage = Loading. So when I do a search in the two words you see radcombox loading ... one imposed by your java function and the set from the property of the combo.
How can I solve this problem?

html code:

<script type="text/javascript">
    function OnClientItemsRequesting(sender, eventArgs) {
        $telerik.$("#" + sender.get_id() + "_DropDown").find(".rcbScroll").prepend("<div id=\"RadComboBox1_LoadingDiv\" class=\"rcbLoading\">Loading...</div>")
    }
    function OnClientItemsRequested(sender, eventArgs) {
        $telerik.$("#" + sender.get_id() + "_DropDown").find(".rcbLoading").remove();
    }
</script>

                            <telerik:RadComboBox ID="Region" Runat="server" CollapseDelay="100"
                                EnableLoadOnDemand="True" HighlightTemplatedItems="True" IsCaseSensitive="True"
                                LoadingMessage="Loading..." DropDownWidth="160px" Filter="StartsWith" Width="160px"
                                MaxHeight="175px" ShowMoreResultsBox="True" Height="175px" OnClientItemsRequesting="OnClientItemsRequesting"
                                AutoPostBack="True" OnSelectedIndexChanged="Region_SelectedIndexChanged" OnClientItemsRequested="OnClientItemsRequested"
                                EmptyMessage="Select region">
                            </telerik:RadComboBox>

bye

[Nencho]

Hello Fabio,

I can suggest you to append the LoadingMessage, only if the ItemsRequested if fired for the first time. You could implement this approach using a flag in a following manner:

<script type="text/javascript">
        var initialLoad = true;

        function OnClientItemsRequesting(sender, eventArgs) {
            if (initialLoad) {

                $telerik.$("#" + sender.get_id() + "_DropDown").find(".rcbScroll").prepend("<div id=\"RadComboBox1_LoadingDiv\" class=\"rcbLoading\">Loading...</div>")
            }
        }
        function OnClientItemsRequested(sender, eventArgs) {
            if (initialLoad) {
                $telerik.$("#" + sender.get_id() + "_DropDown").find(".rcbLoading").remove();
                initialLoad = false;
            }
        }

    </script>

Regards,
Nencho
the Telerik team