azure - 如何从 ServiceBusAttribute 构造函数内部访问环境变量？

Question

我有一个绑定(bind)到服务总线的 azure 函数，我像这样使用它:

[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")

与

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

local.Settings.json:

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

但是我遇到了一个错误:

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

Answer 1

您需要通过用 % 包装环境变量名称来使用绑定(bind)表达式。将队列名称定义为 %MyMessageBusQueueName% ，它将绑定(bind)到环境变量

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

阅读 Microsoft 文档中有关绑定(bind)表达式的信息 --- here .