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Showing posts from April, 2018

An unexpected exception which resulted in a gentle reminder of how Linq works...

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Tonight I spent some time continuing my port of a Mobile Application I developed a few years ago over to UWP. As it was built in Xamarin.Forms , which also supports UWP, so far its been a fairly straight forward process. During testing tonight however I kept getting an uncaught exception every time I tapped a list item.
Specified argument was out of the range of valid values - Source Xamarin.Forms.Core
Now first I double checked the code and found UWP, iOS and Android all run the same code and nothing had changed, so I hadn't accidentally broken anything. What I did note was the pages that didn't have grouped list items worked fine, where as grouped lists always crashed. This lead me to take a look at my ItemSource code for the listview.

Now those observant might notice in the pic I'm inspecting the listingNavigationItems, and like I might have realised the potential issue. Dependent on whether grouping is enabled I either return the first of my grouped sections OR I retu…