adding demos for chapter 16 on SignalR

src/Ch16/SignalRClient/Program.cs

@@ -0,0 +1,38 @@
+using Microsoft.AspNetCore.SignalR.Client;
+
+var connection = new HubConnectionBuilder()
+    .WithUrl("https://localhost:5001/chathub")
+    .WithAutomaticReconnect([TimeSpan.Zero, TimeSpan.FromSeconds(5), TimeSpan.FromSeconds(10)])
+    .Build();
+
+try
+{
+    await connection.StartAsync();
+    Console.WriteLine("Connection started successfully.");
+}
+catch (Exception ex)
+{
+    Console.WriteLine($"Connection failed: {ex.Message}");
+}
+
+connection.On<string, string>("ReceiveMessage", (user, message) =>
+{
+    Console.WriteLine($"{user}: {message}");
+});
+
+await connection.InvokeAsync("SendMessage", "User1", "Hello, SignalR!");
+
+connection.Closed += async (error) =>
+{
+    Console.WriteLine($"Connection closed. Error: {error?.Message}");
+    await Task.Delay(5000); // Wait before attempting to reconnect
+    try
+    {
+        await connection.StartAsync();
+        Console.WriteLine("Reconnection successful.");
+    }
+    catch (Exception ex)
+    {
+        Console.WriteLine($"Reconnection failed: {ex.Message}");
+    }
+};

src/Ch16/SignalRClient/SignalRClient.csproj

@@ -0,0 +1,15 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <OutputType>Exe</OutputType>
+        <TargetFramework>net9.0</TargetFramework>
+        <LangVersion>latest</LangVersion>
+        <ImplicitUsings>enable</ImplicitUsings>
+        <Nullable>enable</Nullable>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <PackageReference Include="Microsoft.AspNetCore.SignalR.Client" Version="9.0.0" />
+    </ItemGroup>
+
+</Project>

src/Ch16/SignalRServerExample/ChatHub.cs

@@ -0,0 +1,11 @@
+namespace SignalRServerExample;
+
+using Microsoft.AspNetCore.SignalR;
+
+public class ChatHub : Hub
+{
+    public async Task SendMessage(string user, string message)
+    {
+        await Clients.All.SendAsync("ReceiveMessage", user, message);
+    }
+}

src/Ch16/SignalRServerExample/Program.cs

@@ -0,0 +1,33 @@
+using SignalRServerExample;
+
+var builder = WebApplication.CreateBuilder(args);
+
+builder.Services.AddSignalR();
+
+var app = builder.Build();
+
+app.UseHttpsRedirection();
+
+app.UseDefaultFiles();
+
+app.UseStaticFiles();
+
+app.UseRouting();
+
+app.Use(async (context, next) =>
+{
+    Console.WriteLine($"Incoming connection: {context.Request.Path}");
+    await next();
+});
+
+app.UseEndpoints(endpoints =>
+{
+    endpoints.MapHub<ChatHub>("/chathub");
+    endpoints.MapFallback(context =>
+    {
+        context.Response.StatusCode = 404;
+        return context.Response.WriteAsync("Endpoint not found.");
+    });
+});
+
+app.Run();

src/Ch16/SignalRServerExample/Properties/launchSettings.json

@@ -0,0 +1,23 @@
+{
+  "$schema": "https://json.schemastore.org/launchsettings.json",
+  "profiles": {
+    "http": {
+      "commandName": "Project",
+      "dotnetRunMessages": true,
+      "launchBrowser": true,
+      "applicationUrl": "http://localhost:5000",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    },
+    "https": {
+      "commandName": "Project",
+      "dotnetRunMessages": true,
+      "launchBrowser": true,
+      "applicationUrl": "https://localhost:5001;http://localhost:5000",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    }
+  }
+}

src/Ch16/SignalRServerExample/SignalRServerExample.csproj

@@ -0,0 +1,13 @@
+<Project Sdk="Microsoft.NET.Sdk.Web">
+
+  <PropertyGroup>
+    <TargetFramework>net9.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.AspNetCore.SignalR" Version="1.1.0" />
+  </ItemGroup>
+
+</Project>

src/Ch16/SignalRServerExample/appsettings.Development.json

@@ -0,0 +1,8 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  }
+}

src/Ch16/SignalRServerExample/appsettings.json

@@ -0,0 +1,9 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  },
+  "AllowedHosts": "*"
+}

src/Ch16/SignalRServerExample/wwwroot/index.html

@@ -0,0 +1,35 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <title>SignalR Test</title>
+    <script src="https://cdnjs.cloudflare.com/ajax/libs/microsoft-signalr/7.0.0/signalr.min.js"></script>
+</head>
+<body>
+<input type="text" id="user" placeholder="Enter your name">
+<input type="text" id="message" placeholder="Enter a message">
+<button onclick="sendMessage()">Send</button>
+
+<ul id="messagesList"></ul>
+
+<script>
+    const connection = new signalR.HubConnectionBuilder()
+        .withUrl("/chathub")
+        .build();
+
+    connection.on("ReceiveMessage", (user, message) => {
+        const li = document.createElement("li");
+        li.textContent = `${user}: ${message}`;
+        document.getElementById("messagesList").appendChild(li);
+    });
+
+    connection.start().catch(err => console.error(err.toString()));
+
+    function sendMessage() {
+        const user = document.getElementById("user").value;
+        const message = document.getElementById("message").value;
+        connection.invoke("SendMessage", user, message)
+            .catch(err => console.error(err.toString()));
+    }
+</script>
+</body>
+</html>

src/Ch16/ch16.sln

@@ -1,8 +1,22 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SignalRServerExample", "SignalRServerExample\SignalRServerExample.csproj", "{D130D4A9-88F6-47D8-A409-4F64F8AD4691}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SignalRClient", "SignalRClient\SignalRClient.csproj", "{B12A3362-5795-4FEF-9FBC-102253CD6BB4}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
 		Release|Any CPU = Release|Any CPU
 	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{D130D4A9-88F6-47D8-A409-4F64F8AD4691}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{D130D4A9-88F6-47D8-A409-4F64F8AD4691}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{D130D4A9-88F6-47D8-A409-4F64F8AD4691}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{D130D4A9-88F6-47D8-A409-4F64F8AD4691}.Release|Any CPU.Build.0 = Release|Any CPU
+		{B12A3362-5795-4FEF-9FBC-102253CD6BB4}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{B12A3362-5795-4FEF-9FBC-102253CD6BB4}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{B12A3362-5795-4FEF-9FBC-102253CD6BB4}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{B12A3362-5795-4FEF-9FBC-102253CD6BB4}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
 EndGlobal