Dear Support,
i have written a small Demo App to scan Barcodes. i’m using the ML Kit for this function.
when i run the following code, i get the following error message.
do you have any tip, what i’m doing wrong?
—- code —-
CaptureConfiguration captureConfiguration = new CaptureConfiguration();
captureConfiguration.AllowMultiple = true;
captureConfiguration.RecentScanCount = 1;
DeviceML deviceML = new DeviceML();
string[] barcodes = deviceML.ScanBarcode(captureConfiguration);
— error message —
mono-rt] [ERROR] FATAL UNHANDLED EXCEPTION: Microsoft.Maui.Platform.HandlerNotFoundException: Handler not found for view Wisej.Hybrid.CameraPreview.Native.CameraPreview.
[mono-rt] at Microsoft.Maui.Platform.ElementExtensions.ToHandler(IElement view, IMauiContext context) in D:\a\_work\1\s\src\Core\src\Platform\ElementExtensions.cs:line 92
[mono-rt] at Microsoft.Maui.Platform.ElementExtensions.ToPlatform(IElement view, IMauiContext context) in D:\a\_work\1\s\src\Core\src\Platform\ElementExtensions.cs:line 127
[mono-rt] at Microsoft.Maui.Handlers.LayoutHandler.SetVirtualView(IView view) in D:\a\_work\1\s\src\Core\src\Handlers\Layout\LayoutHandler.Android.cs:line 41
[mono-rt] at Microsoft.Maui.Handlers.ViewHandler`2[[Microsoft.Maui.ILayout, Microsoft.Maui, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null],[Microsoft.Maui.Platform.LayoutViewGroup, Microsoft.Maui, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].SetVirtualView(IElement view) in D:\a\_work\1\s\src\Core\src\Handlers\View\ViewHandlerOfT.cs:line 56
[mono-rt] at Microsoft.Maui.Controls.Element.SetHandler(IElementHandler newHandler) in D:\a\_work\1\s\src\Controls\src\Core\Element\Element.cs:line 921
[mono-rt] at Microsoft.Maui.Controls.Element.set_Handler(IElementHandler value) in D:\a\_work\1\s\src\Controls\src\Core\Element\Element.cs:line 863
[mono-rt] at Microsoft.Maui.Controls.VisualElement.Microsoft.Maui.IElement.set_Handler(IElementHandler value) in D:\a\_work\1\s\src\Controls\src\Core\VisualElement\VisualElement.cs:line 2061
[mono-rt] at Microsoft.Maui.Platform.ElementExtensions.ToHandler(IElement view, IMauiContext context) in D:\a\_work\1\s\src\Core\src\Platform\ElementExtensions.cs:line 96
[mono-rt] at Microsoft.Maui.Platform.ElementExtensions.ToPlatform(IElement view, IMauiContext context) in D:\a\_work\1\s\src\Core\src\Platform\ElementExtensions.cs:line 127
[mono-rt] at Microsoft.Maui.Handlers.ContentViewHandler.UpdateContent(IContentViewHandler handler) in D:\a\_work\1\s\src\Core\src\Handlers\ContentView\ContentViewHandler.Android.cs:line 42
[mono-rt] at Microsoft.Maui.Handlers.ContentViewHandler.MapContent(IContentViewHandler handler, IContentView page) in D:\a\_work\1\s\src\Core\src\Handlers\ContentView\ContentViewHandler.Android.cs:line 47
[mono-rt] at Microsoft.Maui.PropertyMapper`2.<>c__DisplayClass5_0[[Microsoft.Maui.IContentView, Microsoft.Maui, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null],[Microsoft.Maui.Handlers.IContentViewHandler, Microsoft.Maui, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].<Add>b__0(IElementHandler h, IElement v) in D:\a\_work\1\s\src\Core\src\PropertyMapper.cs:line 172
[mono-rt] at Microsoft.Maui.PropertyMapper.UpdatePropertyCore(String key, IElementHandler viewHandler, IElement virtualView) in D:\a\_work\1\s\src\Core\src\PropertyMapper.cs:line 47
[mono-rt] at Microsoft.Maui.PropertyMapper.UpdateProperties(IElementHandler viewHandler, IElement virtualView) in D:\a\_work\1\s\src\Core\src\PropertyMapper.cs:line 82
[mono-rt] at Microsoft.Maui.Handlers.ElementHandler.SetVirtualView(IElement view) in D:\a\_work\1\s\src\Core\src\Handlers\Element\ElementHandler.cs:line 79
[mono-rt] at Microsoft.Maui.Handlers.ViewHandler`2[[Microsoft.Maui.IContentView, Microsoft.Maui, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null],[Microsoft.Maui.Platform.ContentViewGroup, Microsoft.Maui, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].SetVirtualView(IView view) in D:\a\_work\1\s\src\Core\src\Handlers\View\ViewHandlerOfT.cs:line 53
[mono-rt] at Microsoft.Maui.Handlers.ContentViewHandler.SetVirtualView(IView view) in D:\a\_work\1\s\src\Core\src\Handlers\ContentView\ContentViewHandler.Android.cs:line 26
[mono-rt] at Microsoft.Maui.Handlers.ViewHandler`2[[Microsoft.Maui.IContentView, Microsoft.Maui, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null],[Microsoft.Maui.Platform.ContentViewGroup, Microsoft.Maui, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].SetVirtualView(IElement view) in D:\a\_work\1\s\src\Core\src\Handlers\View\ViewHandlerOfT.cs:line 56
[mono-rt] at Microsoft.Maui.Controls.Element.SetHandler(IElementHandler newHandler) in D:\a\_work\1\s\src\Controls\src\Core\Element\Element.c
— end of error message —
the following NuGets are installed:
Wisej-3 3.5.5-preview.14
Wisej-Barcode 3.5.5-preview.14
Wisej-3-Camera 3.5.5-preview.14
Wisej-3-Hybrid 3.5.5-preview.7
Wisej-3-Hybrid-MLKit 3.5.5-preview.3
Wisej-3-Hybrid-MLKit-Native 3.5.5-preview.3
Wisej-3-Hybrid-Native 3.5.5-preview.7
thank you for your help.
Hi Levie,
thank your for your help. it works now.
another question: is it possible to get source code of your Wisej.NET Haybrid App (see screen shot attached)?
Kind regards
Werner
Hi Werner,
Did you register the MLKit middlware in the Hybrid Client’s Startup class? It will look like this:
If you attach a small and compilable sample project we’re happy to take a look for you.
Best,
Levie
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