Setting Selected Values from SqlDataSource

[Joseph]

I have a SqlDataSource (Regions_SqlDataSource) populating the RadListBox.
I have another SqlDataSource (SelectedRegions_SqlDataSource) that gets the selected values from the database.

I cannot seem to figure out how to set the selected values of the RadListBox based on the SelectedRegions_SqlDataSource.
I can get it to select the first returned value of the SelectedRegions_SqlDataSource, but it does not select all of the returned values.

Here is my code.

Dim regionsSql As DataView = DirectCast(SelectedRegions_SqlDataSource.Select(DataSourceSelectArguments.Empty), DataView)
        For Each regionsviewSql As DataRowView In regionsSql
            If Not Page.IsPostBack And regionsviewSql("PreferenceValue").ToString <> "" Then
                Regions_RadListBox.SelectedValue = regionsviewSql("PreferenceValue")
            End If
        Next

And here is the listbox and data sources.

<telerik:RadListBox ID="Regions_RadListBox" runat="server" Width="200px"
      SelectionMode="Multiple" Rows="3" TextMode="MultiLine" DataSortField="Region"
      DataSourceID="Regions_SqlDataSource1" DataTextField="Region"
      DataValueField="RegionID" Height="60px">
</telerik:RadListBox>

<asp:SqlDataSource ID="Regions_SqlDataSource1" runat="server"
    ConnectionString="<%$ ConnectionStrings:SiteSqlServer %>"
    SelectCommand="SELECT [RegionID], [Region] FROM [NC_CT_Regions]"></asp:SqlDataSource>
<asp:SqlDataSource ID="SelectedRegions_SqlDataSource" runat="server"
    ConnectionString="<%$ ConnectionStrings:SiteSqlServer %>"
    SelectCommand="SELECT PreferenceValue FROM NC_EmployeePreference WHERE PreferenceTypeID = '4' AND EmpID = @EmpID">
    <SelectParameters>
        <asp:QueryStringParameter Name="EmpID" QueryStringField="EmpID" />
    </SelectParameters>
</asp:SqlDataSource>

[Genady Sergeev]

Hello Joseph,

Are you using RadListBox for ASP.NET AJAX?

RadListBox for ASP.NET AJAX does not contain properties such as Rows and TextMode.

With respect to your question, RadListBox can have only one selected value. This means, that if you have 3 selected items, the SelectedValue property will return the value of the firstselected item. If you want to grab the values of all selected items, you can iterate over the ListItems and grab those that are selected.

You can use the RadListBox1.FindItemByValue method in order to search for an item with a given value. Then you can use its Selected property to select it.

Best wishes,
Genady Sergeev
the Telerik team

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[Joseph]

The Rows and TextMode was left over from one of the different things I tried. I took it out now thanks.

The problem that I'm having is that I don't know how to do what you said. I have posted on multiple forums and tried 100 different things to try to iterate through the items in the SqlDataSource and nothing seems to work. As soon as I set the item to "Selected" it gets rid of one of the other items that was selected so that there is only one selected item when the page actually loads. 

Could you possibly go one step further and actually show me the code for how to do this? Please?

[Joshua Holt]

Hi Joseph,

All should work fine if you change you initial load code from

Dim regionsSql As DataView = DirectCast(SelectedRegions_SqlDataSource.Select(DataSourceSelectArguments.Empty), DataView)
        For Each regionsviewSql As DataRowView In regionsSql
            If Not Page.IsPostBack And regionsviewSql("PreferenceValue").ToString <> "" Then
                Regions_RadListBox.SelectedValue = regionsviewSql("PreferenceValue")
            End If
        Next

To:

Dim regionsSql As DataView = DirectCast(SelectedRegions_SqlDataSource.Select(DataSourceSelectArguments.Empty), DataView)
        For Each regionsviewSql As DataRowView In regionsSql
            If Not Page.IsPostBack And regionsviewSql("PreferenceValue").ToString <> "" Then
                Regions_RadListBox.FindItemByValue(regionsviewSql("PreferenceValue") ).Selected = true
            End If
        Next

Then on post back, you can grab
Regions_RadListBox.SelectedItems and loop over them. 

The slight change there is not setting the SelectedValue, but actually grabbing each item you want to select, and then selecting it. 
Hope that works for ya!
Joshua Holt

[Joseph]

"Then on post back, you can grab
Regions_RadListBox.SelectedItems and loop over them. "

How exactly would I do this part? That's where I am having a problem. 

[Joshua Holt]

Hi Joseph,
I have attached an example based on the northwind database.  It is doing pretty much what you are doing.  It lists the employees in a RadCombobox, and all territories in a RadListBox,  when you select an employee it selects all territories they are associated with.  Then when you click "Post Territories" it will load the selected items from the list box to a panel.
I hope this helps you.
You can download the example here: Example 
Thank you,
Joshua Holt

[Genady Sergeev]

Hello Joseph,

The easiest way is to use the SelectedItems property of the RadListBox object. By "grab the selected items" I meant the following:

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
        Dim item As Telerik.Web.UI.RadListBoxItem
        For Each item In RadListBox1.Items
            If (item.Selected = True) Then
                'You can do whatever you want with the selected files
                Response.Write(item.Value)
            End If
        Next
    End Sub

Greetings,
Genady Sergeev
the Telerik team

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Watch a video on how to optimize your support resource searches and check out more tips on the blogs.

[Joseph]

Thanks Genady, this will help me when I am trying to get the values out of the listbox. I'm still trying to figure out how to actually set the selected items right now, but this will definitely help as soon as I get to his point.

I'm still trying to figure out what's happening in the example I was given, there's so much going on there and I'm still so new to this it's hard for me to get just the info I need out of such a complex example. 

[Joshua Holt]

Hi Joseph,
Sorry if the example was a bit complex.  I have simplified it a little, and fully commented it, and you can get the new version here: Clearer Example

You will mostly just need to look at the Default.aspx.vb file, as the "RadComboBox1_SelectedIndexChanged" change function shows you how to select items in the list box, and the "Button1_Click" function shows you how to loop over the selected items in a listbox.

Joshua Holt

[Joseph]

Thank you very much, I appreciate all the help.

I've just been pulled off of this for another project, so I will have to get to it later, but I downloaded the files and have them when I am put back on this. 

Again, thank you guys for all your help!