Signalr C# (Wie es für Entwickler funktioniert)

Setting Up Your Development Environment

To get started, you’ll need:

• ASP.NET Core SDK
• Visual Studio

Building the SignalR Hub

At its core, SignalR revolves around a SignalR hub, a central point for both the client and the server to interact.

Create a new ASP.NET Core project. Now, add a new class and name it ChatHub. This will act as our SignalR hub.

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

// Define a SignalR Hub class named ChatHub
public class ChatHub : Hub
{
    // Asynchronous method to send messages
    public async Task SendMessage(string user, string message)
    {
        // Send a message to all connected clients
        await Clients.All.SendAsync("ReceiveMessage", user, message);
    }
}

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

// Define a SignalR Hub class named ChatHub
public class ChatHub : Hub
{
    // Asynchronous method to send messages
    public async Task SendMessage(string user, string message)
    {
        // Send a message to all connected clients
        await Clients.All.SendAsync("ReceiveMessage", user, message);
    }
}

Imports Microsoft.AspNetCore.SignalR
Imports System.Threading.Tasks

' Define a SignalR Hub class named ChatHub
Public Class ChatHub
	Inherits Hub

	' Asynchronous method to send messages
	Public Async Function SendMessage(ByVal user As String, ByVal message As String) As Task
		' Send a message to all connected clients
		Await Clients.All.SendAsync("ReceiveMessage", user, message)
	End Function
End Class

In the Startup class, let's integrate our hub.

public class Startup
{
    // Configure services and add SignalR
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddSignalR(); // Add SignalR services
    }

    // Configure the app to use SignalR and map the hub
    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        // Setup endpoint to route to ChatHub
        app.UseEndpoints(endpoints =>
        {
            endpoints.MapHub<ChatHub>("/chatHub");
        });
    }
}

public class Startup
{
    // Configure services and add SignalR
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddSignalR(); // Add SignalR services
    }

    // Configure the app to use SignalR and map the hub
    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        // Setup endpoint to route to ChatHub
        app.UseEndpoints(endpoints =>
        {
            endpoints.MapHub<ChatHub>("/chatHub");
        });
    }
}

Public Class Startup
	' Configure services and add SignalR
	Public Sub ConfigureServices(ByVal services As IServiceCollection)
		services.AddSignalR() ' Add SignalR services
	End Sub

	' Configure the app to use SignalR and map the hub
	Public Sub Configure(ByVal app As IApplicationBuilder, ByVal env As IWebHostEnvironment)
		' Setup endpoint to route to ChatHub
		app.UseEndpoints(Sub(endpoints)
			endpoints.MapHub(Of ChatHub)("/chatHub")
		End Sub)
	End Sub
End Class

Using the SignalR Client Library

The SignalR client library lets your client-side code connect and communicate directly with the server side. For our example, let's use JavaScript.

First, add the SignalR JavaScript client library:

<script src="https://cdn.jsdelivr.net/npm/@microsoft/signalr@3.1.8/dist/browser/signalr.js"></script>

<script src="https://cdn.jsdelivr.net/npm/@microsoft/signalr@3.1.8/dist/browser/signalr.js"></script>

Now, you can connect to the hub:

// Create a connection to the SignalR hub
const connection = new signalR.HubConnectionBuilder()
    .withUrl("/chatHub") // The hub URL
    .build();

// Start the connection
connection.start().catch(err => console.error(err.toString()));

// Setup a listener for receiving messages
connection.on("ReceiveMessage", (user, message) => {
    console.log(`${user} says: ${message}`);
});

// Create a connection to the SignalR hub
const connection = new signalR.HubConnectionBuilder()
    .withUrl("/chatHub") // The hub URL
    .build();

// Start the connection
connection.start().catch(err => console.error(err.toString()));

// Setup a listener for receiving messages
connection.on("ReceiveMessage", (user, message) => {
    console.log(`${user} says: ${message}`);
});

This simple client-side code connects to the hub and listens for any messages broadcast.

Sending Messages

Using our earlier client-side and server-side code snippets, sending messages is straightforward. Both the server and the client can initiate communication.

From server-side:

// Send a message from the server to all connected clients
await Clients.All.SendAsync("ReceiveMessage", "Server", "Hello from server!");

// Send a message from the server to all connected clients
await Clients.All.SendAsync("ReceiveMessage", "Server", "Hello from server!");

' Send a message from the server to all connected clients
Await Clients.All.SendAsync("ReceiveMessage", "Server", "Hello from server!")

And from client:

// Send a message from the client to the server
connection.send("SendMessage", "Client", "Hello from client!")
    .catch(err => console.error(err.toString()));

// Send a message from the client to the server
connection.send("SendMessage", "Client", "Hello from client!")
    .catch(err => console.error(err.toString()));

Advanced Real-Time Communication

ASP.NET Core SignalR offers advanced real-time communication features:

1. Grouping Connections: Segment connected clients into groups, broadcasting messages to specific segments.
2. Handling Disconnections: Automatically manage client connections and disconnections.
3. Binary Protocol: While SignalR uses a text-based protocol by default, it supports a binary protocol as well.

SignalR with Azure SignalR Service

For scalable real-time functionality, integrate Azure SignalR Service. This fully managed service supports massive numbers of simultaneous connections, making it ideal for high-demand apps.

Integrating Azure SignalR Service:

1. Install the Azure SignalR SDK.
2. Use Azure Service Bus for backplane support.
3. Adjust the Startup class to use Azure SignalR.

public class Startup
{
    public void ConfigureServices(IServiceCollection services)
    {
        // Add Azure SignalR services
        services.AddSignalR().AddAzureSignalR();
    }

    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        // Use Azure SignalR and map hub with routes
        app.UseAzureSignalR(routes =>
        {
            routes.MapHub<ChatHub>("/chatHub");
        });
    }
}

public class Startup
{
    public void ConfigureServices(IServiceCollection services)
    {
        // Add Azure SignalR services
        services.AddSignalR().AddAzureSignalR();
    }

    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        // Use Azure SignalR and map hub with routes
        app.UseAzureSignalR(routes =>
        {
            routes.MapHub<ChatHub>("/chatHub");
        });
    }
}

Public Class Startup
	Public Sub ConfigureServices(ByVal services As IServiceCollection)
		' Add Azure SignalR services
		services.AddSignalR().AddAzureSignalR()
	End Sub

	Public Sub Configure(ByVal app As IApplicationBuilder, ByVal env As IWebHostEnvironment)
		' Use Azure SignalR and map hub with routes
		app.UseAzureSignalR(Sub(routes)
			routes.MapHub(Of ChatHub)("/chatHub")
		End Sub)
	End Sub
End Class

IronPDF

Learn more about IronPDF capabilities lets you generate, edit, and read PDF files within your .NET applications. Imagine integrating SignalR in a scenario where a team collaborates on a document in real-time. As changes are made, the document can be converted to a PDF on the fly, with updates pushed to all connected clients seamlessly. The real-time functionality of SignalR paired with IronPDF's capabilities could revolutionize collaborative tools.

IronPDF converts HTML, URLs, and full webpages into stunning PDFs like the original. It’s perfect for saving online reports, invoices, or any web-based information you want to keep. Are you looking to turn HTML to PDF? Try IronPDF today!

using IronPdf;

class Program
{
    static void Main(string[] args)
    {
        var renderer = new ChromePdfRenderer();

        // 1. Convert HTML String to PDF
        var htmlContent = "<h1>Hello, IronPDF!</h1><p>This is a PDF from an HTML string.</p>";
        var pdfFromHtmlString = renderer.RenderHtmlAsPdf(htmlContent);
        pdfFromHtmlString.SaveAs("HTMLStringToPDF.pdf");

        // 2. Convert HTML File to PDF
        var htmlFilePath = "path_to_your_html_file.html"; // Specify the path to your HTML file
        var pdfFromHtmlFile = renderer.RenderHtmlFileAsPdf(htmlFilePath);
        pdfFromHtmlFile.SaveAs("HTMLFileToPDF.pdf");

        // 3. Convert URL to PDF
        var url = "http://ironpdf.com"; // Specify the URL
        var pdfFromUrl = renderer.RenderUrlAsPdf(url);
        pdfFromUrl.SaveAs("URLToPDF.pdf");
    }
}

using IronPdf;

class Program
{
    static void Main(string[] args)
    {
        var renderer = new ChromePdfRenderer();

        // 1. Convert HTML String to PDF
        var htmlContent = "<h1>Hello, IronPDF!</h1><p>This is a PDF from an HTML string.</p>";
        var pdfFromHtmlString = renderer.RenderHtmlAsPdf(htmlContent);
        pdfFromHtmlString.SaveAs("HTMLStringToPDF.pdf");

        // 2. Convert HTML File to PDF
        var htmlFilePath = "path_to_your_html_file.html"; // Specify the path to your HTML file
        var pdfFromHtmlFile = renderer.RenderHtmlFileAsPdf(htmlFilePath);
        pdfFromHtmlFile.SaveAs("HTMLFileToPDF.pdf");

        // 3. Convert URL to PDF
        var url = "http://ironpdf.com"; // Specify the URL
        var pdfFromUrl = renderer.RenderUrlAsPdf(url);
        pdfFromUrl.SaveAs("URLToPDF.pdf");
    }
}

Imports IronPdf

Friend Class Program
	Shared Sub Main(ByVal args() As String)
		Dim renderer = New ChromePdfRenderer()

		' 1. Convert HTML String to PDF
		Dim htmlContent = "<h1>Hello, IronPDF!</h1><p>This is a PDF from an HTML string.</p>"
		Dim pdfFromHtmlString = renderer.RenderHtmlAsPdf(htmlContent)
		pdfFromHtmlString.SaveAs("HTMLStringToPDF.pdf")

		' 2. Convert HTML File to PDF
		Dim htmlFilePath = "path_to_your_html_file.html" ' Specify the path to your HTML file
		Dim pdfFromHtmlFile = renderer.RenderHtmlFileAsPdf(htmlFilePath)
		pdfFromHtmlFile.SaveAs("HTMLFileToPDF.pdf")

		' 3. Convert URL to PDF
		Dim url = "http://ironpdf.com" ' Specify the URL
		Dim pdfFromUrl = renderer.RenderUrlAsPdf(url)
		pdfFromUrl.SaveAs("URLToPDF.pdf")
	End Sub
End Class

IronXL

When it comes to working with Excel spreadsheets, Explore IronXL Features is a champion. In a business setting, spreadsheets play a vital role. Incorporating SignalR alongside IronXL means that financial teams could work on budget sheets in real-time, witnessing changes as they happen. Imagine a scenario where data entries from various departments flow into a centralized Excel sheet, with real-time updates for all stakeholders. The fusion of real-time communication and dynamic spreadsheet management becomes a reality with this combination.

IronOCR

Optical Character Recognition (OCR) has become a staple in modern applications. See IronOCR in action empowers .NET developers to extract text from images and documents. Pairing this with SignalR's real-time functionality can be game-changing. Consider a platform where users upload images containing textual data. SignalR could be used to notify users in real-time once IronOCR processes the images, making data extraction interactive and instantaneous.

IronBarcode

Barcoding is integral in inventory management, ticketing systems, and more. Discover IronBarcode Capabilities simplifies the creation and reading of barcodes. Now, think of integrating this with SignalR in a warehouse management system. As items are scanned, the inventory gets updated in real-time, notifying connected clients of stock levels, and ensuring a smooth logistical operation.