Hello,

From your sample, which events are fired? I could not test it your issue since i don't have any your database. So, i tried to make the sample with similar settings in WebCombo,WebGrid and page load. If it is WebCombo InitializeDataSource, then it is the default behaviour. 

Regards,
Handy

Hi Handy

Following Events are fired if I dropdown WebCombo wcProduct:

1. Page_Load
2. grd_InitializeLayout
3. grd_InitializeDataSource
4. grd_PrepareDataBinding
5. wcProduct_InitializeDataSource
6. wcLine_InitializeDataSource

Hi Michael,

After I discussed with our developer, they said that is is default behaviour.
Event if it is not integrated into WebGrid, the WebGrid IntializeLayour event would be called (WebGrid IntializeDataSource and PrepareDataBinding would be called only when it needs new datasource).
When clicked on WebCombo dropdown, it would initiate ajax callback just like in full Postback behaviour. All control life cycle should remain the same.
Otherwise, it'll break a lot of architecture.
Although the event would be called, but you can customize with your own validation to check if the codes inside those event needs to be called or not.

e.g

if (grid.IsFlyPostBack) or if(!ISPostBack) then do the code

Regards,
Handy