在Async方法中绑定到输出blob时，将Blob绑定到IAsyncCollector时出错

我试图在这篇文章之后绑定到Async方法中的blob输出： 如何将输出值绑定到我的异步Azure函数？

我有多个输出绑定，所以只返回不是一个选项

public static async Task Run(HttpRequestMessage req, IAsyncCollector collection, TraceWriter log) { if (req.Method == HttpMethod.Post) { string jsonContent = await req.Content.ReadAsStringAsync(); // Save to blob await collection.AddAsync(jsonContent); return req.CreateResponse(HttpStatusCode.OK); } else { return req.CreateResponse(HttpStatusCode.BadRequest); } } 

我对blob的绑定是：

 { "bindings": [ { "authLevel": "function", "name": "req", "type": "httpTrigger", "direction": "in" }, { "name": "$return", "type": "http", "direction": "out" }, { "type": "blob", "name": "collection", "path": "testdata/{rand-guid}.txt", "connection": "test_STORAGE", "direction": "out" } ], "disabled": false } 

但每当我这样做，我得到以下内容：

错误：函数（$ WebHook）错误：Microsoft.Azure.WebJobs.Host：错误索引方法’Functions.WebHook’。 Microsoft.Azure.WebJobs.Host：无法绑定Blob以键入’Microsoft.Azure.WebJobs.IAsyncCollector`1 [System.String]’

Answer 1

Blob输出绑定不支持收集器，请参阅此问题 。

对于可变数量的输出blob（在您的情况下为0或1，但可以是任何），您将不得不使用命令式绑定。 从function.json删除collection绑定，然后执行以下操作：

 public static async Task Run(HttpRequestMessage req, Binder binder) { if (req.Method == HttpMethod.Post) { string jsonContent = await req.Content.ReadAsStringAsync(); var attributes = new Attribute[] { new BlobAttribute("testdata/{rand-guid}.txt"), new StorageAccountAttribute("test_STORAGE") }; using (var writer = await binder.BindAsync(attributes)) { writer.Write(jsonContent); } return req.CreateResponse(HttpStatusCode.OK); } else { return req.CreateResponse(HttpStatusCode.BadRequest); } }