Azure EventGrid（已创建 Blob）函数输出流

Question

如果我创建一个 azure 函数 Blob Trigger，我可以定义 Blob 的输入流和我想写入一些数据的输出流，签名类似于下面。

public async Task RunAsync(
            [BlobTrigger(BlobPath, Connection = "FileStorage")]
            Stream inputStream,
            [Blob(OutputBlobPath, FileAccess.Write, Connection = "FileStorage")]
            Stream outputStream,
            /* other fields removed for brevity */
            ) 
{ 
    /* ... */
}

是否可以在使用为创建 blob 时触发的 EventGrid 触发器定义类似的内容？ 即

  public async Task RunAsync(
            [EventGridTrigger] EventGridEvent eventGridEvent, 
            [Blob("{data.url}", FileAccess.Read, Connection = "FileStorage")] Stream input,
/* is something like this possible -> */ [Blob(?, FileAccess.Write, Connection = "FileStorage")] Stream output)
        {
            /* ... */
        }

Answer 1

可以为 blob 绑定到 CloudBlobContainer 而不是 Stream，后者为 blob 提供完整的存储 API。它看起来像这样：

public static async Task Run(
    [EventGridTrigger] EventGridEvent eventGridEvent,
    [Blob(/* container params */)] CloudBlobContainer blobContainer,
    ILogger log)
{
   // Use blobContainer to read/write blobs in container
}

来自Azure docs：

You can bind to the following types to write blobs:

TextWriter
out string
out Byte[]
CloudBlobStream
Stream
CloudBlobContainer
CloudBlobDirectory
ICloudBlob
CloudBlockBlob
CloudPageBlob
CloudAppendBlob

Answer 2

当然你可以在 EvenGrid 触发函数中使用输出流。我在本地测试它。首先，我上传了一个名为“input.txt”的blob，内容为“input”。运行我的函数后，我上传另一个 blob（或删除另一个 blob）来触发触发器，然后将内容“input”添加到名为“test.txt”的 blob 中。

这是我的代码。

 [FunctionName("Function1")]
        public static async System.Threading.Tasks.Task RunAsync([EventGridTrigger] EventGridEvent eventGridEvent,
           [Blob("sample-items/input.txt", FileAccess.Read, Connection = "AzureWebJobsStorage")] Stream input,
           [Blob("sample-items/test.txt", FileAccess.Write, Connection = "AzureWebJobsStorage")] Stream output)
        {
            await input.CopyToAsync(output);
                    ......
         }