Cascading DropDown or RadComboBox in RadGrid popup mode

[Aaron Hanusa]

I am using a RadGrid and utilizing the popup edit mode.

For simplicity sake, I have 2 DropDown lists (although these could easily be RadComboBoxes).  In the first one I have Countries, and the second one I have Cities.  Select a Country, the second DropDownList is populated with Cities.  Pretty standard functionality, nothing special here.

I would like to bind the selected values to an object's properties.  Lets say an Address object's .CountryID and .CityID properties for sake of argument.

<telerik:RadComboBox ID="ddlCountries" Runat="server" SelectedValue='<%#Bind("CountryID") %>' AutoPostBack="true" DataSourceID="countriesDataSource"  DataTextField="Country" DataValueField="CountryID"/>

<telerik:RadComboBox ID="ddlCities" Runat="server" SelectedValue='<%#Bind("CityID") %>' DataSourceID="citiesDataSource"  DataTextField="City" DataValueField="CityID"/>

ddlCountries can bind to the object fine in either edit or insert mode.  The problem lies in when ddlCities attempts to bind to the object.  I forget the exception that is thrown at this point, but it has something to do with ddlCities not being a bindable object.

I have figured out a solution to get this to work.  Admittedely, it is far more hackish than I hoped it to be.  I basically have to populate ddlCities manually after ddlCountries has changed and manually populate ddlCities with values (can't use a DataSource object).  What's worse is that I have to handle a few RadGrid events to manually select the City that should bind to the object's City property, rather than allow the elegance of the Bind() method to perform its work.  Again, it works, but it's quite an ugly solution.

Has anyone experienced this and have a code sample that they'd like to share?  I can share mine to upon request.

Thanks!

[Pavlina]

Hi Aaron,

To see more information along the lines of the requested functionality, please refer to the following article:
http://www.telerik.com/community/code-library/aspnet-ajax/general/using-related-radcomboboxes-in-radgrid.aspx

I hope it gets you started properly.

All the best,
Pavlina
the Telerik team

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[Aaron Hanusa]

Hi Pavlina,

Thanks for the reply and the code sample.  Unfortunately, the code does not address my issue.  In fact, you are using MORE code than my code, which I consider to be hackish.  Please don't take offense to that, but I think you may have missed my point as you aren't utilizing the Bind() method declaratively within the RadCombo's.

Thanks

[Pavlina]

Hi Aaron,

Based on this information, it is hard to determine what is causing the issue you are facing. 
Therefore I will ask you to open a formal support ticket and provide us runnable example which replicates the error. Thus we'll be able to assist you further.

Sincerely yours,
Pavlina
the Telerik team

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[Justin McMillen]

Have you been able to find a solution for this?  I am having the same problem.

Thanks.

[Aaron Hanusa]

I don't believe I did.  I think I just moved on because Telerik wasn't addressing my issue.  Sorry...

[Pavlina]

Hello Aaron and Justin,

I suggest you try out the following code to populate a combobox based on the selection in another combobox in the grid:
ASPX:

<telerik:GridTemplateColumn UniqueName="ContactTitle" HeaderText="ContactTitle">
     <EditItemTemplate>
         <telerik:RadComboBox ID="RadComboBox1" AutoPostBack="true" runat="server" SelectedValue='<%# Bind("CountryID") %>' DataSourceID="SqlDataSource1" DataTextField="CountryID"  OnSelectedIndexChanged="RadComboBox1_SelectedIndexChanged">
         </telerik:RadComboBox>
     </EditItemTemplate>
</telerik:GridTemplateColumn>

<telerik:GridTemplateColumn UniqueName="TemplateColumn">
     <EditItemTemplate>
         <telerik:RadComboBox ID="RadComboBox2"  runat="server">
         </telerik:RadComboBox>
     </EditItemTemplate>
</telerik:GridTemplateColumn>

C#:

protected void RadComboBox1_SelectedIndexChanged(object o, RadComboBoxSelectedIndexChangedEventArgs e)
    {
        RadComboBox rdcbx = (RadComboBox)o;
        GridEditableItem editedItem = rdcbx.NamingContainer as GridEditableItem;
        RadComboBox ddList = editedItem.FindControl("RadComboBox2") as RadComboBox;
        // change the data source for ddList here
         .....
    }

I hope this helps.

Greetings,
Pavlina
the Telerik team

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