JakeWindle
JakeWindle
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Created by JakeWindle on 11/13/2023 in #help
SignalR client method calling C#/JS interop, hangs indefinitely.
Hey all, I have a project that I've been working on that involves heavy usage of SignalR and C#/JS interop. The basic flow goes like this: 1. On SignalR connect, send the client a message GetDimensions that the client acts on. 2. When client receives GetDimensions, call C# service class that imports JS module 3. C# service class calls JS function to grab screen dimensions, await result 4. Return result as ValueTask<ScreenDimensions> from service class. 5. Call the SignalR hub SetScreenDimensions method with the return from the service class. My problem: This is working fine on Linux, but on Windows (using Edge and Chrome), the code I've noted with // THIS HANGS HERE won't run. I can see in teh JS console that I'm reaching that client method, but that call I'm awaiting hangs indefinitely. Code samples: Client Receive Method 
    hubConnection.On("GetDimensions", async () =>
    {
        var dimensions = await _screenInfo.GetDimensions(); // THIS HANGS HERE, does JS stuff
        await hubConnection.SendAsync(
            "CalculateDisplayArea",
            dimensions.width,
            dimensions.height,
            0);
    });
    hubConnection.On("GetDimensions", async () =>
    {
        var dimensions = await _screenInfo.GetDimensions(); // THIS HANGS HERE, does JS stuff
        await hubConnection.SendAsync(
            "CalculateDisplayArea",
            dimensions.width,
            dimensions.height,
            0);
    });
ScreenInfo class method: 
    public async ValueTask<ScreenDimensions> GetDimensions()
    {
        if (_screenDimensions is not null)
        {
            return _screenDimensions;
        }

        // Load the module if null.
        _module ??= await _js.InvokeAsync<IJSObjectReference>("import", _dbModulePath);

        _screenDimensions = await _module.InvokeAsync<ScreenDimensions>("getDimensions");
        return _screenDimensions;
    }
    public async ValueTask<ScreenDimensions> GetDimensions()
    {
        if (_screenDimensions is not null)
        {
            return _screenDimensions;
        }

        // Load the module if null.
        _module ??= await _js.InvokeAsync<IJSObjectReference>("import", _dbModulePath);

        _screenDimensions = await _module.InvokeAsync<ScreenDimensions>("getDimensions");
        return _screenDimensions;
    }
Anything glaringly wrong? I can't figure out why this call would work on Linux, but it would hang on Windows. dotnet version: 7.0.402
6 replies