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How to implement multicolumn loadondemand without ExternalCallBackPage

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henk
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henk asked on 14 Feb 2008, 11:33 AM
I am migrating from RadControls to Prometheus. I got a compiler error stating that property ExternalCallBackPage no longer exist. Searching the forum I saw that I have to use a webservice instead of ExternalCallBackPage.

However I want to create a multi column combobox using a header and item template. The webservice in the example given returns an array of RadComboBoxItemData objects. How can I use a webservice to populate a multicolumn combobox?

 

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Mike
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answered on 14 Feb 2008, 01:23 PM
You don't need to use a web service.  Just set a regular event handler for OnItemsRequested and it should work fine.
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henk
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answered on 14 Feb 2008, 01:50 PM
Mike,

Thanks for the answer. I have used ExternalCallBackPage sofar for a reason: my ASPX page containing the ComboBox is rather heavy. If I use the regular OnItemsRequested handler the complete page is initialised every time.

Is a workaround available?

Roland
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Veselin Vasilev
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answered on 15 Feb 2008, 04:58 PM
Hi henk,

In the Page Load event handler you can put your initialization code in the

if (!IsPostBack && !Page.IsCallBack
 //your init code here 

Now when you load items on demand  the IsCallBack will be true and the whole statement false so you will not initialize the page again.

I hope this helps.

Regards,
Veskoni
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Mike
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henk
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Veselin Vasilev
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