Unhandled exception when using C# wrapper with Blazor-Web-Assembly-App

[PhilippJR]

Description

I followed the recommended steps for including the C# wrapper with Nuget package. This works well for console applications but not for Blazor-Web-Assembly-Apps, where I get an unhandled exception.

Steps to Reproduce in Visual Studio 2019

1. Create new console application
2. Add Nuget package SharpFluids
3. In Programm.cs replace all code with:

using SharpFluids;
using System;
using UnitsNet;

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Hello World!");

            var Water = new Fluid(FluidList.Water);
            Water.UpdatePT(Pressure.FromBars(1.013), Temperature.FromDegreesCelsius(13));
            Console.WriteLine("Density of water at 13°C: " + Water.Density);
            Console.ReadLine();
        }
    }
}

4. Run app, everythink works well.
5. Create new Blazor-Web-Assembly-App. On the Additional information window check Progressive Web Application.
6. Add Nuget package SharpFluids
7. In Index.razor replace all code with:

@page "/"
@using SharpFluids
@using UnitsNet

<h1>Hello, world!</h1>
<button class="btn btn-primary" @onclick="TestPR">Click me</button>
<span>@waterDensity</span>

@code{ private UnitsNet.Density waterDensity;
    private void TestPR()
    {
        var water = new Fluid(FluidList.Water);
        water.UpdatePT(Pressure.FromBars(1.013), Temperature.FromDegreesCelsius(13));
        waterDensity = water.Density;
    } }

8. Run app, click button, see the unhandled exception error.

The exception occurs in the line var water = new Fluid(FluidList.Water); Please see message from Visual Studio Output window below.

Versions

CoolProp Version: Nuget package SharpFluids 2.0.93
Operating System and Version: Windows 10
Access Method: Visual Studio Professional 2019 Version 16.10.2 , C#

Additional Information

crit: Microsoft.AspNetCore.Components.WebAssembly.Rendering.WebAssemblyRenderer[100] Unhandled exception rendering component: The type initializer for 'CoolPropPINVOKE' threw an exception. System.TypeInitializationException: The type initializer for 'CoolPropPINVOKE' threw an exception. ---> System.TypeInitializationException: The type initializer for 'SWIGExceptionHelper' threw an exception. ---> System.DllNotFoundException: CoolProp at CoolPropPINVOKE.SWIGExceptionHelper..cctor() --- End of inner exception stack trace --- at CoolPropPINVOKE..cctor() --- End of inner exception stack trace --- at AbstractState.factory(String backend, String fluid_names) at SharpFluids.Fluid.SetNewMedia(MediaType Type) at SharpFluids.Fluid..ctor(MediaType Media) at SharpFluids.Fluid..ctor(FluidList Type) at WebApplication4.Pages.Index.TestPR() in C:\Users<user>\source\repos\WebApplication4\Pages\Index.razor:line 17 at Microsoft.AspNetCore.Components.EventCallbackWorkItem.InvokeAsync[Object](MulticastDelegate delegate, Object arg) at Microsoft.AspNetCore.Components.EventCallbackWorkItem.InvokeAsync(Object arg) at Microsoft.AspNetCore.Components.ComponentBase.Microsoft.AspNetCore.Components.IHandleEvent.HandleEventAsync(EventCallbackWorkItem callback, Object arg) at Microsoft.AspNetCore.Components.EventCallback.InvokeAsync(Object arg) at Microsoft.AspNetCore.Components.RenderTree.Renderer.DispatchEventAsync(UInt64 eventHandlerId, EventFieldInfo fieldInfo, EventArgs eventArgs)

[ibell]

Is it even possible in general to use PINVOKE in C# in Blazor to call shared libraries that are binary? My gut says no.

[PhilippJR]

I googled "blazor pinvoke binary" and found some comments but I do not understand the details. Could you please invest few minutes? If using the CoolProp.dll in Blazor is not possible, is there another way to implement the calculations?

[ibell]

I'm afraid you are on your own; I can't dig into this question given my constraints. I don't think it will be possible, unless you can recompile CoolProp into WASM. You can get javascript WASM, but I have no idea if Blazor can call this generated WASM. I would avoid SharpFluids if possible, to keep it simple(r).

[PhilippJR]

OK Ian, I will try to find a solution and let you know if I do so.