Azure service bus read all messages at once using Azure.Messaging.ServiceBus

As suggested by @gaurav Mantri, I used ServiceBusProcessor class to implement event based model for processing messages

 public async Task ReceiveAll()
    {
        string connectionString = "Endpoint=sb://sb-test-today.servicebus.windows.net/;SharedAccessKeyName=manage;SharedAccessKey=8e+6SWp3skB3Aedsadsadasdwz5DU=;";
        string topicName = "topicone";
        string subscriptionName = "subone";
        await using var client = new ServiceBusClient(connectionString, new ServiceBusClientOptions
        {
            TransportType = ServiceBusTransportType.AmqpWebSockets
        });

        var options = new ServiceBusProcessorOptions
        {
            // By default or when AutoCompleteMessages is set to true, the processor will complete the message after executing the message handler
            // Set AutoCompleteMessages to false to [settle messages](https://learn.microsoft.com/en-us/azure/service-bus-messaging/message-transfers-locks-settlement#peeklock) on your own.
            // In both cases, if the message handler throws an exception without settling the message, the processor will abandon the message.
            AutoCompleteMessages = false,

            // I can also allow for multi-threading
            MaxConcurrentCalls = 1
        };

        await using ServiceBusProcessor processor = client.CreateProcessor(topicName, subscriptionName, options);

        processor.ProcessMessageAsync += MessageHandler;
        processor.ProcessErrorAsync += ErrorHandler;

        await processor.StartProcessingAsync();

        Console.ReadKey();
    }


    public async Task MessageHandler(ProcessMessageEventArgs args)
    {
        string body = args.Message.Body.ToString();
        Console.WriteLine(body);

        // we can evaluate application logic and use that to determine how to settle the message.
        await args.CompleteMessageAsync(args.Message);
    }

    public Task ErrorHandler(ProcessErrorEventArgs args)
    {
        // the error source tells me at what point in the processing an error occurred
        Console.WriteLine(args.ErrorSource);
        // the fully qualified namespace is available
        Console.WriteLine(args.FullyQualifiedNamespace);
        // as well as the entity path
        Console.WriteLine(args.EntityPath);
        Console.WriteLine(args.Exception.ToString());
        return Task.CompletedTask;
    }