c# - 仅在第一次使用 Azure Function HttpTrigger 从主题获取消息时使用 MessageReceiver

Question

仅第一次使用MessageReceiver使用Azure函数从主题获取消息，之后下次执行函数时，尽管我有消息进入服务总线主题，但变量仍然为空消息.

使用下面的代码从服务总线主题获取消息，原因是什么？

string serviceBusConnectionString = Environment.GetEnvironmentVariable("ConnectionString");
var messageReceiver = new MessageReceiver(serviceBusConnectionString, Environment.GetEnvironmentVariable("topicName/subscriptions/subscriptionName"), ReceiveMode.PeekLock, null, 500);

var messages = await messageReceiver.ReceiveAsync(500, TimeSpan.FromSeconds(1));

i can't understand this - after every 15 minutes when LA call FA then FA should able to read new available messages but it is coming null

与锁定持续时间有什么关系吗？

Answer 1

var messages = await messageReceiver.ReceiveAsync(500, TimeSpan.FromSeconds(1));

将等待，直到收到一条或多条消息，然后返回。稍后传入的任何消息都不会被读取。如果你想这样做(我怀疑这在 Azure 函数中是否是一个好主意)，请将其放入循环中:

while(/* some condition */)
{
     messages = await messageReceiver.ReceiveAsync(500, TimeSpan.FromSeconds(1));
     // do something with the received messages
}