Pfthb

I'm trying to integrate the SignalR Core JS client on React Native but can't quite seem to get it to work with a ASP.NET Core server with SignalR. I've heard that other people have been able to make it work despite the lack of a designated React Native client.

I keep getting the following error: "Error: Failed to complete negotiation with the server: Error". Could someone help me?

Here's what the React Native app looks like:

App.js

import React, Component from 'react';
import Platform, StyleSheet, Text, View, TouchableHighlight, TextInput, Alert from 'react-native';

import * as signalR from '@aspnet/signalr';

export default class App extends Component 

 componentDidMount() 
 let connection = new signalR.HubConnectionBuilder()
 .withUrl("http://192.168.0.89:5000/app")
 .configureLogging(signalR.LogLevel.Information)
 .build();

 connection.on("ReceiveMessage", (user, message) => 
 const msg = message.replace(/&/g, "&amp;").replace(/</g, "&lt;").replace(/>/g, "&gt;");
 const encodedMsg = user + " says " + msg;
 log(encodedMsg);
 );

 connection.start().catch(err => this.logError(err));
 

 render() 
 return (
 <View style=styles.container>

 </View>
 );
 



const styles = StyleSheet.create(
 container: 
 flex: 1,
 justifyContent: 'center',
 alignItems: 'center',
 backgroundColor: '#F5FCFF',
 
);

Package.json

 "name": "TakMobile",
 "version": "0.0.1",
 "private": true,
 "scripts": 
 "start": "node node_modules/react-native/local-cli/cli.js start",
 "test": "jest"
 ,
 "dependencies": 
 "@aspnet/signalr": "^1.0.4",
 "react": "16.6.0-alpha.8af6728",
 "react-native": "0.57.4",
 "react-native-callkit": "^1.3.4",
 "react-native-voip-push-notification": "^1.1.2",
 "react-native-webrtc": "^1.67.1",
 "socket.io-client": "^2.1.1"
 ,
 "devDependencies": 
 "babel-jest": "23.6.0",
 "jest": "23.6.0",
 "metro-react-native-babel-preset": "0.49.0",
 "react-test-renderer": "16.6.0-alpha.8af6728"
 ,
 "jest": 
 "preset": "react-native"
 

Here's what the server looks like:

Startup.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.DependencyInjection;

namespace demo1

 public class Startup
 
 // This method gets called by the runtime. Use this method to add services to the container.
 // For more information on how to configure your application, visit https://go.microsoft.com/fwlink/?LinkID=398940
 public void ConfigureServices(IServiceCollection services)
 
 services.AddSignalR();
 

 // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
 public void Configure(IApplicationBuilder app, IHostingEnvironment env)
 
 if (env.IsDevelopment())
 
 app.UseDeveloperExceptionPage();
 

 app.UseFileServer();
 app.UseSignalR(routes =>
 
 routes.MapHub<ApplicationHub>("/app");
 );
 
 

Program.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Logging;

namespace demo1

 public class Program
 
 public static void Main(string args)
 
 CreateWebHostBuilder(args).Build().Run();
 

 public static IWebHostBuilder CreateWebHostBuilder(string args) =>
 WebHost.CreateDefaultBuilder(args)
 .UseStartup<Startup>();
 

Demo1.cs project file

<Project Sdk="Microsoft.NET.Sdk.Web">

 <PropertyGroup>
 <TargetFramework>netcoreapp2.1</TargetFramework>
 </PropertyGroup>

 <ItemGroup>
 <Folder Include="wwwroot" />
 </ItemGroup>

 <ItemGroup>
 <PackageReference Include="Microsoft.AspNetCore.App" />
 </ItemGroup>

</Project>

launchSettings.json

 "iisSettings": 
 "windowsAuthentication": false, 
 "anonymousAuthentication": true, 
 "iisExpress": 
 "applicationUrl": "http://192.168.0.89:5002",
 "sslPort": 44397
 
 ,
 "profiles": 
 "IIS Express": 
 "commandName": "IISExpress",
 "launchBrowser": true,
 "environmentVariables": 
 "ASPNETCORE_ENVIRONMENT": "Development"
 
 ,
 "demo1": 
 "commandName": "Project",
 "launchBrowser": true,
 "applicationUrl": "http://192.168.0.89:5000",
 "environmentVariables": 
 "ASPNETCORE_ENVIRONMENT": "Development"
 
 
 

ApplicationHub.cs

using System.Threading.Tasks;
using Microsoft.AspNetCore.SignalR;

namespace demo1 
 public class ApplicationHub : Hub 
 public Task Send(string message) 
 return Clients.All.SendAsync("Send", message);
 
 

Turns out React Native had an issue connecting perhaps because of the https protocol. Furthermore, I also explicitly added 'Microsoft.AspNetCore.SignalR' version 1.0.4 to match the version on React Native even though it should be included in 'Microsoft.AspNetCore.App'.

So, here's the updated code that works on both React and React Native:

App.js

import React, Component from 'react';
import Platform, StyleSheet, Text, View, TouchableHighlight, TextInput, Alert from 'react-native';

import * as signalR from '@aspnet/signalr';

export default class App extends Component 

 componentDidMount() 
 const hubUrl = 'http://192.168.0.89:5000/app';

const connectionHub = new signalR.HubConnectionBuilder()
 .withUrl(hubUrl)
 .configureLogging(signalR.LogLevel.Information)
 .build();

connectionHub.on('ReceiveMessage', this.messageReceived);
connectionHub.start()
 .catch(err => this.logError(err));
 

 render() 
 return (
 <View style=styles.container>

 </View>
 );
 



const styles = StyleSheet.create(
 container: 
 flex: 1,
 justifyContent: 'center',
 alignItems: 'center',
 backgroundColor: '#F5FCFF',
 
);

Here's what the server looks like:

Startup.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.DependencyInjection;

namespace demo1

 public class Startup
 
 // This method gets called by the runtime. Use this method to add services to the container.
 // For more information on how to configure your application, visit https://go.microsoft.com/fwlink/?LinkID=398940
 public void ConfigureServices(IServiceCollection services)
 
 services.AddSignalR();
 services.AddCors();
 services.AddMvc();
 

 // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
 public void Configure(IApplicationBuilder app, IHostingEnvironment env)
 
 if (env.IsDevelopment()) 
 
 app.UseDeveloperExceptionPage();
 
 app.UseCors(cors => 
 cors.AllowAnyHeader();
 cors.AllowAnyOrigin();
 cors.AllowAnyMethod();
 cors.AllowCredentials();
 );
 app.UseSignalR(routes =>
 
 routes.MapHub<ApplicationHub>("/app");
 );


 app.UseHttpsRedirection();
 app.UseWebSockets();
 app.UseMvc();

 
 

Demo1.cs project file

 <Project Sdk="Microsoft.NET.Sdk.Web">

 <PropertyGroup>
 <TargetFramework>netcoreapp2.1</TargetFramework>
 </PropertyGroup>

 <ItemGroup>
 <Folder Include="wwwroot" />
 </ItemGroup>

 <ItemGroup>
 <PackageReference Include="Microsoft.AspNetCore.App" />
 <PackageReference Include="Microsoft.AspNetCore.SignalR" Version="1.0.4" />
 </ItemGroup>

</Project>

launchSettings.json

 
 "iisSettings": 
 "windowsAuthentication": false, 
 "anonymousAuthentication": true, 
 "iisExpress": 
 "applicationUrl": "http://*:5002",
 "sslPort": 44397
 
 ,
 "profiles": 
 "IIS Express": 
 "commandName": "IISExpress",
 "launchBrowser": true,
 "environmentVariables": 
 "ASPNETCORE_ENVIRONMENT": "Development"
 
 ,
 "demo1": 
 "commandName": "Project",
 "launchBrowser": true,
 "applicationUrl": "http://*:5000;https://*:5001",
 "environmentVariables": 
 "ASPNETCORE_ENVIRONMENT": "Development"