如何从 ServiceBusAttribute 构造函数内部访问环境变量？

Question

我有一个绑定到服务总线的 azure 函数，我是这样使用它的：

[FunctionName("MyFunctionName")]
public async Task<IActionResult> Run(
[HttpTrigger(AuthorizationLevel.Function, "get", "post", Route = null)] HttpRequest req,
[ServiceBus("myqueueortopicname", Connection = "ServiceBusConnection")] IAsyncCollector<string> messages)

我正在尝试使服务总线队列名称可配置并取自 Environment.GetEnvironmentVariable("MyMessageBusQueueName")

有

[ServiceBus(Environment.GetEnvironmentVariable("MyMessageBusQueueName"), Connection = "ServiceBusConnection")] IAsyncCollector<string> messages)`

local.Settings.json:

{
    "IsEncrypted": false,
    "Values": {
        "MyMessageBusQueueName": "myqueueortopicname",
        "ServiceBusConnection": "..."
    },
    "ConnectionStrings": {}
}

但是我有一个错误：

An attribute argument must be a constant expression, typeof expression or array

Answer 1

您需要用 % 包裹环境变量名称来使用绑定表达式。将队列名称定义为 %MyMessageBusQueueName%，它将绑定到环境变量

[ServiceBus("%MyMessageBusQueueName%", Connection = "ServiceBusConnection")] IAsyncCollector<string> messages)

在 Microsoft 文档中阅读有关绑定表达式的信息 ---here。

如何从 ServiceBusAttribute 构造函数内部访问环境变量？

How to access the environment variables from inside ServiceBusAttribute constructor?

azure

azureservicebus

azure-functions