VisionApi.Create not get correct App

Hi!

When start demo example, i have error, there is a workaround?:

Parameter name: app’. Callstack: ’ at Firebase.MLKit.Vision.VisionApi.Create (Firebase.Core.App app) <0x1502279c8 + 0x00014> in <8607cf18847b4467a58b3fd7d84f75f1>:0 at GoogleVisionBarCodeScanner.UICameraPreview+CaptureVideoDelegate…ctor (System.Boolean vibrationOnDetected) [0x0004c] in D:\BarcodeScanner.XF-master\GoogleVisionBarCodeScanner\iOS\UICameraPreview.cs:178 at GoogleVisionBarCodeScanner.UICameraPreview.Initialize (System.Boolean defaultTorchOn, System.Boolean vibrationOnDetected, System.Boolean startScanningOnCreate) [0x0011a] in D:\BarcodeScanner.XF-master\GoogleVisionBarCodeScanner\iOS\UICameraPreview.cs:141 at GoogleVisionBarCodeScanner.UICameraPreview…ctor (System.Boolean defaultTorchOn, System.Boolean vibrationOnDetected, System.Boolean startScanningOnCreate) [0x00008] in D:\BarcodeScanner.XF-master\GoogleVisionBarCodeScanner\iOS\UICameraPreview.cs:39 at GoogleVisionBarCodeScanner.Renderer.CameraViewRenderer.OnElementChanged (Xamarin.Forms.Platform.iOS.ElementChangedEventArgs1[TElement] e) [0x00059] in D:\BarcodeScanner.XF-master\GoogleVisionBarCodeScanner\iOS\Renderer\CameraViewRenderer.cs:25 at Xamarin.Forms.Platform.iOS.VisualElementRenderer1[TElement].SetElement (TElement element) [0x00172] in D:\a\1\s\Xamarin.Forms.Platform.iOS\VisualElementRenderer.cs:296

[AdrianBylica]

Does it works if you set the linker behaviour to No Link?

No, this don’t work in all option (Don’t Link, SDK only and All linked) also with and without Hot reload. off course the GoogleServices-info.plist is set to - BundleResource

This could be a bug from the Firebase library for Xamarin iOS. xamarin/GoogleApisForiOSComponents#452 Could you please check if Firebase.Core.App.DefaultInstance (after Firebase.Core.App.Configure()) is null or not? if it is null, please try to add the parameter to the config function to see if it is null or not. In fact, there is nothing I can do with this.

result is null 2021-04-14 17:17:47.405 Xamarin.PreBuilt.iOS[934:93167] Firebase App App.DefaultInstance IS NULL

Sorry, just look back to your previous comment. You should disable HOT-RESTART instead of hot reload. They are different.

To disable hot restart, please refer to https://docs.microsoft.com/en-us/xamarin/xamarin-forms/deploy-test/hot-restart.

Xamarin Hot Restart is disabled by default on Visual Studio 16.8 and previous versions. 
You can enable it under Tools > Options > Environment > Preview Features > Enable Xamarin Hot Restart. 
Starting in Visual Studio 16.9, Xamarin Hot Restart is on by default and can be turned off from Tools > Options > Xamarin > iOS Settings > Enable Hot Restart.

I guess some firebase libraries are static libraries that do not support hot restart and as a result, it cannot be activated.

If you are using Visual Studio for Windows, please try to disable the hot-restart and try again. If you are using Visual Studio for Mac, I think it is good to go.

I do not have Windows right now so I could not try it. I am looking forward to your feedback.

Ok Jimmy, i have try this all option in Windows without success, the disable Hot Reload option also eliminate use my real device, so i have run to VS in MAC and the problem disappear. So, for all People that will use this in iOS platform don’t try this in Windows this only waste your time, go to Visual studio in MAC. Thanks for help.

[JimmyPun610]

Hi @decv86,

Just like above comment, please try to disable HOT-RESTART / use Visual Studio for Mac to debug.