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Blazor JS interop [Bug]

See original GitHub issue

Description

Calling JS from C# in MAUI-Blazor app not work.

Steps to Reproduce

RCL with JS interop wrapped to C# class
Call

Expected Behavior

Work same as with browser. With browser same RCL work.

Actual Behavior

Basic Information

Version with issue:
Last known good version:
IDE: VS19.VS22
Platform Target Frameworks:
- Android: emulator

"Object reference not set to an instance of an object."

   at Microsoft.AspNetCore.Components.WebView.Services.WebViewJSRuntime.BeginInvokeJS(Int64 taskId, String identifier, String argsJson, JSCallResultType resultType, Int64 targetInstanceId) in Microsoft.AspNetCore.Components.WebView.dll:token 0x6000113+0x0
   at Microsoft.JSInterop.JSRuntime.InvokeAsync[IJSObjectReference](Int64 targetInstanceId, String identifier, CancellationToken cancellationToken, Object[] args) in Microsoft.JSInterop.dll:token 0x600003a+0x10a
   at Microsoft.JSInterop.JSRuntime.<InvokeAsync>d__16`1[[Microsoft.JSInterop.IJSObjectReference, Microsoft.JSInterop, Version=6.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60]].MoveNext() in Microsoft.JSInterop.dll:token 0x60000a8+0xf7
   at Obletsvet.Ui.Mobile.Components.SwipeMenu.InitAsync() in C:\Projects\Obletsvet\Obletsvet\src\Obletsvet.Ui.Mobile.Components\SwipeMenu.cs:line 35
   at Obletsvet.Ui.Mobile.Components.Shared.TopBar.OnAfterRenderAsync(Boolean firstRender) in C:\Projects\Obletsvet\Obletsvet\src\Obletsvet.Ui.Mobile.Components\Shared\TopBar.razor:line 97

Also notice #1245 and ipcSender looks like it is also not set in android

Issue Analytics

State:
Created 2 years ago
Comments:8 (4 by maintainers)

Top GitHub Comments

1reaction

MackinnonBuckcommented, Nov 17, 2022

If we enable scope validation, error like this will yield much more useful messages. Since we can’t reasonably change the IJSRuntime to be registered as a singleton service in MAUI Blazor, let’s use this issue to track enabling scope validation.

1reaction

Eiloncommented, Oct 14, 2021

I think that the JS interop type in your app needs to be registered as Scoped and not Singleton (just like in Blazor Server).

But we should try to make this have a better experience.