Error: System.InvalidOperationException: The current thread is not associated with the Dispatcher. Use InvokeAsync() to switch execution to the Dispatcher when triggering rendering or component state.

 

[2022-06-13T09:10:08.300Z] Error: System.InvalidOperationException: The current thread is not associated with the Dispatcher. Use InvokeAsync() to switch execution to the Dispatcher when triggering rendering or component state.

   at Microsoft.AspNetCore.Components.Dispatcher.AssertAccess()

   at Microsoft.AspNetCore.Components.RenderTree.Renderer.AddToRenderQueue(Int32 componentId, RenderFragment renderFragment)

   at Microsoft.AspNetCore.Components.ComponentBase.StateHasChanged()

   at Microsoft.AspNetCore.Components.ComponentBase.Microsoft.AspNetCore.Components.IHandleEvent.HandleEventAsync(EventCallbackWorkItem callback, Object arg)

   at BlazorBarcodeScanner.ZXing.JS.BarcodeReader.ReceivedBarcodeText(BarcodeReceivedEventArgs args)

   at System.Threading.Tasks.Task.<>c.<ThrowAsync>b__139_0(Object state)

   at Microsoft.AspNetCore.Components.Rendering.RendererSynchronizationContext.ExecuteSynchronously(TaskCompletionSource`1 completion, SendOrPostCallback d, Object state)

   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)

--- End of stack trace from previous location where exception was thrown ---

   at Microsoft.AspNetCore.Components.Rendering.RendererSynchronizationContext.ExecuteBackground(WorkItem item)

在Blazor Server中若有去使用StateHasChanged通常是為了叫UI做即時響應刷新

但若是寫在async 修飾的非同步方法中或者開另一個Thread的運行時要記得改為

InvokeAsync(StateHasChanged);

Ref:

https://blazor-university.com/components/multi-threaded-rendering/invokeasync/