c# - Azure函数: async method and output parameters

Question

我想在我的azure函数中使用输出队列。我从以下位置获取示例代码: https://learn.microsoft.com/en-us/sandbox/functions-recipes/queue-storage

[FunctionName("BasicQueueOutput")]
public static void Run([TimerTrigger("*/30 * * * * *")]TimerInfo myTimer,
                       TraceWriter log,
                       [Queue("101functionsqueue",Connection = "AzureWebJobsStorage")] out string queueMessage)
{
    log.Info("101 Azure Function Demo - Storage Queue output");

    queueMessage = DateTime.UtcNow.ToString();
}

它对于同步方法工作得很好，但在我的例子中它是异步方法:

    [FunctionName("FunctionRegisterDomain")]
    public async static Task Run(
        [QueueTrigger("domain-registation", Connection = "StorageConnectionString")]DomainForRegistration queueItem,
        [Queue("domain-add-to-office365", Connection = "StorageConnectionString")]out DomainForRegistration outputQueue,
        ILogger log)

我收到一个错误:

Async methods cannot have ref, in or out parameters

当然，我能做到:

    [Queue("domain-add-to-office365", Connection = "StorageConnectionString")]CloudQueue outputQueue,

然后使用它:

await outputQueue.AddMessageAsync(new CloudQueueMessage(JsonConvert.SerializeObject(queueItem)));

但我想通过绑定(bind)到队列消息来做到这一点

Answer 1

您正在寻找IAsyncCollector<T>从 out 参数更改为那个。您将“out string message”更改为ICollector<string> messages，而不是“out string message”或IAsyncCollector<string>并将您的消息添加到正文中的集合中。