So probably i have found the cause of the problem, the combobox was correct, but the source was xmlprovider, which was running asynchronous by the default.

this code fixed it:



xmlsourcedata.I sAsynchronous=f alse;

xmlsourcedata.I sInitialLoadEna bled = true;

xmlsourcedata.D ocument.InnerXm l = trn2.GetRootNod e().OuterXml;

...

Hello, i am using WPF combobox in my application.
1) I create and add a combobox to a visual container (usualy Grid) by runtime or it is defined in the XAML page
2) I assign combobox source to the new xmldocument, this loads the content and then document xml data populate the combo items
3) When page init is finished i load page data to setup the form, I set loaded comboboxes to the selecteditems
4) page.show();
...