使用Azure函数进行更新以挂钩到SignalR广播

Question

所以我在这里学习了几个教程：https://docs.microsoft.com/en-us/azure/azure-signalr/signalr-quickstart-azure-functions-csharp和https://docs.microsoft.com/en-us/azure/azure-signalr/signalr-concept-serverless-development-config

我的问题是，所有的示例都显示了一个CRON操作，或者只是一个作用域内的控制台日志广播。但是我希望通过更新集合来触发广播吗？

在Web应用程序中，我可以这样做。当使用多个客户端进行测试时，这种方法工作得很好。

[HttpPost]
public async Task<IActionResult> Insert([FromQuery] string firstName, string lastName)
{
     await _repo.InsertNewPerson(firstName, lastName);
     //This hub essentially has almost nothing set up except: 
     // endpoints.MapHub<ContactsHub>("/contacts");  setup in startup
     await _hub.Clients.All.SendAsync("transfercontactdata", _repo.GetContacts());
     return StatusCode(201);
}

然而，在一个Azure函数中，我看到了下面这段代码:使用微软的预制类添加一个'Broadcast‘SignalRTrigger

public class SignalRTestHub : ServerlessHub
{
    private IContactsRepo _repo = new ContactsRepo();

    [FunctionName("negotiate")]
    public SignalRConnectionInfo Negotiate([HttpTrigger(AuthorizationLevel.Anonymous, "post")] HttpRequest req, [SignalRConnectionInfo(HubName = "SignalRTestHub")] SignalRConnectionInfo connectionInfo)
    {
        return connectionInfo;
    }

    //Brett: Do I need this arg more in other events to ensure this acts as a load balancer??? ... ran out of time, [SignalRConnectionInfo(HubName = "SignalRTestHub")] SignalRConnectionInfo connectionInfo
    [FunctionName(nameof(OnConnected))]
    public async Task OnConnected([SignalRTrigger] InvocationContext invocationContext, ILogger logger, [SignalRConnectionInfo(HubName = "SignalRTestHub")] SignalRConnectionInfo connectionInfo)
    {
        //await Clients.All.SendAsync(NewConnectionTarget, new NewConnection(invocationContext.ConnectionId));
        logger.LogInformation($"{invocationContext.ConnectionId} has connected");
    }

    [FunctionName(nameof(Broadcast))]
    public async Task Broadcast([SignalRTrigger] InvocationContext invocationContext, string message, ILogger logger)
    {
        //Broadcast on update the same as the get call on the other function
        await Clients.All.SendAsync("getting data", await _repo.GetContacts());
        logger.LogInformation($"{invocationContext.ConnectionId} broadcast {message}");
    }

    [FunctionName(nameof(OnDisconnected))]
    public void OnDisconnected([SignalRTrigger] InvocationContext invocationContext)
    {
    }
    
}

然后，我有另一个HTTP触发器函数，如下所示：

public static class SignalRTesting
{
    private static IContactsRepo _repo  = new ContactsRepo();
    private static SignalRTestHub _hub = new SignalRTestHub();
    private static SignalRConnectionInfo _info;

    static SignalRTesting()
    {
        //Not sure how connect or need to
        _info = _hub.Negotiate(null, null);
    }

    [FunctionName("GetData")]
    public static async Task<IActionResult> GetData([HttpTrigger(AuthorizationLevel.Anonymous, "get", Route = null)] HttpRequest req, ILogger log) => new OkObjectResult(await _repo.GetContacts());

    [FunctionName("UpdateData")]
    public static async Task<IActionResult> UpdateData([HttpTrigger(AuthorizationLevel.Anonymous, "post", Route = null)] HttpRequest req, ILogger log)
    {
        string requestBody = await new StreamReader(req.Body).ReadToEndAsync();
        var data = JsonConvert.DeserializeObject<Contact>(requestBody);
        await _repo.InsertNewPerson(data.FirstName, data.LastName);
        await _hub.Broadcast()  //I need a context from above I am guessing

        return new NoContentResult();
    }
}

所以我的问题是，如何获得HTTP POST或PUT请求，以便使用函数调用广播？在我看来，集线器广播需要一个连接，所以几乎就像有一个服务端充当客户端一样，但我不确定。

Answer 1

在Azure函数中，您只需利用SignalR Service Output Binding向所有客户端广播即可。其余的由底层的库来处理。