Fix Windows unexpected exceptions in multi-page applications.

paoldev commented 7 months ago

Fixes Redth/ZXing.Net.Maui#141 for Windows. Edit: also fixes #159

This PR

makes cameraPreview unloading phase more robust, mainly for multi-page, Shell-based applications
tries to automatically restart the camera feed when returning to the page containing the unloaded cameraPreview control, in multi-page, Shell-based applications

All these commits are needed to address issue Redth/ZXing.Net.Maui#141 for Windows.

A multi-page BigIslandBarcode test application can be found at https://github.com/paoldev/ZXing.Net.Maui/tree/AppShell, where "MainPage" and "Page 2" contain a camera control, whereas "Page 1" is just an empty page.

paoldev commented 7 months ago

CI build errors seem to be related to SkiaSharp dependency for net7.0-maccatalyst, which is unrelated to this PR code.

paoldev commented 5 months ago

According to comments in #159, this PR also seems to fix issues described there.

Redth / ZXing.Net.Maui