输入绑定到自定义类似乎不适用于blob

Question

My Azure Function has two input parameters:

• Event Hubs trigger
• Blob input binding

I am trying to bind both parameters to custom type (F# record in my case). Binding works fine for the trigger, but not for blog binding, which gives the following error:

Microsoft.Azure.WebJobs.Host: Error indexing method 'Functions.MailboxFanOut'. 
Microsoft.Azure.WebJobs.Host: Can't bind Blob to type 'Run+CustomerName'.

Here is the code:

[<CLIMutable>]
type CustomerName = {
    UserName: string
}

let Run(item: CustomerName, userNames: CustomerName, log: TraceWriter) =
    log.Verbose("F# function executing")

Replacing F# record with a class doesn't help...

Here is the function definition:

{
  "bindings": [
    {
      "type": "eventHubTrigger",
      "name": "item",
      "direction": "in",
      "path": "blabla",
      "connection": "eventhubs",
      "consumerGroup": "$Default"
    },
    {
      "type": "blob",
      "name": "userNames",
      "path": "tada/123",
      "connection": "foo",
      "direction": "in"
    }
  ],
  "disabled": false
}

Answer 1

The blob bindings unfortunately don't currently support POCO bindings as you'd expect. We have an open issue in our repo tracking this here .

To work around that, I recommend binding to a Stream, string, or one of the other supported types and doing the deserialization into your POCO type in your method.